S T U D Y P R O T O C O L Open Access
The use of digitally collected patient-
reported outcome measures for newly
operated patients with total knee and hip
replacements to improve post-treatment
recovery: study protocol for a randomized
controlled trial
David Kuklinski
*
, Laura Oschmann, Christoph Pross, Reinhard Busse and Alexander Geissler
Abstract
Background: The number of total knee replacements (TKRs) and total hip replacements (THRs) has been increasing
noticeably in hig h-income countries, such as Germany. In particular, the number of revisions is expected to rise
because of higher life expectancy and procedures performed on younger patients, impacting the budgets of
health-care systems. Quality transparency is the basis of holistic patient pathway optimization. Nevert heless, a
nation-wide cross-sectoral assessment of quality from a patient perspective does not yet exist. Several studies have
shown that the use of patient-reported out come measures (PRO Ms) is effective for measuring quali ty and
monitoring post-treatment recovery. For the first time in Germany, we test whether early detection of critical
recovery paths using PROMs after TKR/THR improves the quali ty of care in a cost-effective way and can be
recommended for implementa tion into standard care.
Methods/design: The study is a two-arm multi-center patient-level randomized controlled trial. Patients from nine
hospitals are included in the study. Patient-ce ntered questionnaires are emplo yed to regularly measure digitized
PROMs of TKR/THR patients from the time of hospital admissi on until 12 months post-discharge. An expert
consortium has defined PROM alert thresh olds at 1, 3, and 6 months to signal critical recovery paths after TKR/THR.
An algorithm alerts study assistants if patients are not recovering in line with expected recovery paths. The study
assistants contact patients and th eir physicians to investigate and, if needed, adjust the post-treatment protocol.
When sickness funds ’ claims data are added, the cost-effectiveness of the interv ention can be analyzed.
Discussion: The study is expected to deliver an important contribution to test PROMs as an intervention tool and
examine the determinants of high-quality endoprosthe tic care. Depending on a positive and cost-effective impact,
the goal is to transfer the study design into standard care. During the trial design phase, sever al insights have been
discovered, and there were opportunities for efficient digita l monitoring limited by existing legacy care model s.
(Continued on next page)
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* Correspondence: [email protected]
Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
Kuklinski et al. Trials (2020) 21:322
https://doi.org/10.1186/s13063-020- 04252-y

(Continued from previous page)
Digitalization in hospital pr ocesses and the implementat ion of digital tools still represent challenges for hospital
personnel and patients. Furthermore, data privacy regulations and the separation between the in- and outpatient
sector are roadblocks to effectively monitor and assess quality along the full patient pathway.
Trial registration: German Clinical Trials Register: DRKS00019916 . Registered November 26, 2019 – retrospectively
registered.
Keywords: Health-care policy, PROM, Quality of care, TKR, THR, Value-based health care, Randomized controlled trial
Background
Total knee replacements (TKRs) and total hip replace-
ments (THRs) are among the most freq uent and increasing
surgeries in high-income cou ntries, such as Germany. They
are considered to be effective but also highly invasive pro-
cedures to treat ost eoarthritis in the knee and hip . In 2016,
in Germany, there were mor e than 187,000 procedures
(230 per 100,000 population) for TKRs – a 38% increase
compared with 2006 – and 233,000 p rocedures (280 per
100,000 population) for THRs – a 17% increase compared
with 2006 [ 1 – 3 ]. Moreover, th e number of primary as well
as revision procedures is exp ected to rise steadily because
of i nc re a se d li f e ex pe cta n c ie s an d pr oc ed u re s pe rf o rm ed
on younger patients [ 2 ]. This d evelopment has a s ignificant
impact on the bud gets of health-care syst ems. Measuring
patient-reported quality help s to generate transparency, to
evaluate treatments, and as a consequence to optimize pa-
tients ’ pathways (indication, procedure, and recovery), lead-
ing to enlarged revision horizons and a decreased number
of revision s [ 4 ].
Quality of joint replacement in Germany is measured
and monitored by several mandator y or voluntary initia-
tives. They concentrate on the collection and analyses of
clinical q uality indicator s and adm i ni st ra t iv e data a s wel l as
the adherence to stru ctural and processual standards and
the interp retation of medical documen t ation [ 5 ]. These
quality initiatives are limited mostly to the acute inpatient
sector [ 6 ] . A nation-w ide st andardized and cross-sectoral
assessment of quality from a patient persp ective does not
exist yet. As a result, the improvement of arthroplasty-
relevant problems such as post-operati ve joint functional-
ity, pain, or constraints in dai ly life cannot be assessed by
the existing quality measu rement tools. However, an im-
provement in t hose quality dimensions defines treatment
success [ 7 ] and significantly affects patient utility [ 8 ]. Con-
sequently, a recent study in the UK concluded th at, for
patients with THR, quality measured by patient-reported
outcomes (PROMs) significantly affects patient utility in
th e fo r m o f wi ll i ngn e s s to tr av el a n d hos p it al d em an d po si -
ti v el y. I n co n tr as t, e xi s ti ng q ua l ity ind i ca to r s suc h a s mo r-
tality rates or r eadmission rates have either only a small
positive or even insignificant effect [ 8 ].
Furt he rmo re, inc re ase d tr ansp aren cy of th e pa tien ts ’ re-
cov ery pr oc ess us ing PR OMs i niti ates a di rect f eedb ack
mech an ism bet ween ph ys ici an and pati en t, thus opt imi z-
ing su rg eri es [ 9 , 10 ] an d bes t prac ti ce sh arin g [ 7 ]. At
pres en t this is b arel y giv en. Af ter re hab ilit at ion, pa ti ents
wil l seld om re tu rn to th e hosp ita l for foll ow-u p vi sits and
inst ea d they see th eir fami ly phys ici an s or outpat ie nt spe-
ci ali sts. Unf or tuna te ly, co mmun ica tion ch an nels be tw een
hosp it als an d fol low- up ph ysici a ns are ofte n no t pres ent,
prev en ting an y feed ba ck mech an ism re gard ing th ei r pa-
tien ts ’ re cov ery pr oces s [ 11 ].
For example, the effects of improved medical quality
by continuously monitorin g patients after surg ery using
PROMs have bee n concluded in a study of patients with
cancer [ 12 , 13 ]. The study shows that, during routine
treatment, cons ta nt moni tori ng an d earl y dete cti on of
cr itic al re cove ry pa ths vi a PROM s si gnifi ca ntl y imp rove d
su rviv al rate s and de cre ased th e number o f emer genc y
vi sits [ 12 , 13 ].
Our study is designed to go beyond testing the effect -
iveness of PROM s as a quality measurement instrument.
For the first time in Germany , we want to test whether
an early detection of critical recov ery paths after TKR /
THR via PROMs and change of post-treatment pathways
improves clin ical quality indicators such as readmissions
and pa ti ent- ce nter ed qu ali ty meas ur es su ch as heal th -
re late d qual ity o f life an d joi nt fu ncti ona li ty and, i n turn ,
le ads to a de crea se o f heal th- care co st s. Th e stud y focu ses
on tw o spec ifi c ques ti ons : (a) Ca n the us e of PR OMs af te r
TKR/ TH R impa ct th e pati ent pa th way i n a posi tiv e and
cost -e ffe cti ve mann er ? (b ) Can we reco mmen d the imp le -
ment at ion of PRO Ms into st anda rd ca re, and wh at are
best pr ac tice s to foll ow?
Methods/Design
Overall study design
This study is a two-a rm multi-center patien t-level ran-
domized controlled trial (RCT). Patient-cente red ques-
tionnaires are employed digitally to regu larly mea sure
PROMs of patients with TKR and THR from the time of
hospital admission until 12 months after discharge. With
the support of an expert consortiu m of physicians,
PROM threshold alert values at 1, 3, and 6 months have
been define d to signal critical recovery of patients after
TKR/THR. Wi th the help of an algorithm, patie nts and
Kuklinski et al. Trials (2020) 21:322 Page 2 of 10

post-treatment physicians are alerted to intervene in
case of critical PROM values.
By addi ng cr oss- se ctor al ins ur ance cl ai ms data (r es ourc e
cons um ptio n: drug s, ph ys ioth erap y, spec ial ist vi si ts, co m-
pli cati on s, infe ctio ns , and hosp ita l stays) at th e pati ent
le vel, th e stud y exam in es the ef fect of PRO M-b ased m oni-
tori ng of pati en ts up to 12 mont hs po st- surg ery on the
cl ini cal as we ll as pati ent- re port ed ou tc ome s and i ts co st-
effe ct iven es s.
Ethics, consent, permissions, and funding
The study is funded by the Innovation Fund of the German
Federal Joint Committee (G-BA) in the st ream “ Care
models with comprehensive a nd measurable results and
process responsibi lity ” . The funding period is set between
April 1, 2019 and March 31, 2023. The study will be con-
ducted in accordance with the D eclaration of Helsinki. The
study was ap proved prima rily by the Charit é ’ sE t h i cC o m -
mittee, Berlin (EA 4/169/19). The other responsible ethical
review committees of particip ating hospitals (Medical
Chamber Hamburg, M edical Chamber Schleswig-Holstein,
Hannover Medical School, Friedrich-Schiller University
Jena, and Medical Chamber Brandenburg) agreed with the
decision. The study is registered at the German Clinical
Trials Register (DR KS) under t rial number DRKS00 019916.
All potentially eligible par ticipants will be approached to
offer their informed consent to participate in the study.
The current protocol is version 1, dated Ja nuary 15, 20 20.
Any changes in the study design will be communicated to
all project partners, including hospitals.
Study setting
The study started on October 1, 2019 and w ill last for two
years, whereas patient recruitment will end after one year,
on September 30, 2020. T he second year will c oncentrate
on follow-ups and correspo nding interventions. After two
years, the study will be evaluated by an independent and
impartial research institute ( aQua Institute, Göttingen,
Germany). Study centers are th en i n ep a r t i c i p a t i n gh o s p i -
tals. These hospitals are located around Germany (seven
different federal states) and are among Germany ’ s leading
endoprosthetic centers. Hospi tals differ in their type, in-
cluding university hospitals, s pecialized e ndoprosthetic cen-
ters, full-service providers, and specialist outpatient clinics.
Based on histori cal hospital case volumes for elective
TKR/THR to estim ate expected workload, up to two
study assistan ts are employ ed at each ce nter – funde d
by means of the Innovation Fund – to operation alize the
study design in each center. Before the start of the pro-
ject, these stud y assistants were trained thoroughly in
workshops to be in line with the specification s of the
study design. The study assistan ts are responsib le for all
study-related activities during the patie nts ’ hospit al stay
and for follow-u p as well as the initiation and
documentation of inte rventions and a complete final
documentation of the participa nt after 12 months.
The st udy as sist an ts and pati en ts use a so ftwa re int er-
face pr ov ide d by HRTBT Medi ca l Solu tion s Gmb H
(Ber lin , Germ an y), a digi ta l sol uti ons pr ovi der fo r hosp i-
tals , to docu ment pa tien t en roll ment , ke y pr oce dure as -
pe cts, an d the pati en t-re po rted out com es. Pati en ts ’ he al th
pro cedu re an d clai ms data along th e care pa th way ar e
acce ss ed vi a the pa rt icip at ing Ge rm an si ckne ss fu nd s
BARM ER and BK K, b oth o f whic h ar e part of th e so cial
heal th ins ur ance sc heme [ 14 ]. Th es e ins uran ce cla ims da ta
wil l be ex tr acte d fo r fou r ye ars (2 01 8 – 20 21 ) for tho se pa-
tien ts in sure d in one of thes e fund s and ha ving co nsen te d
to stud y desi gn an d data shar in g.
Sample size
The estimation of the study ’ s sample size is based on
historical case volumes (iden tified by procedur e codes
OPS 5 – 820 and 5 – 822) of the nin e study hospit als from
2018. Hence, we expect arou nd 17,500 patien ts to be eli-
gible in the 12-mo nth recruiting time frame. Th is figure
already exclud es emergency patients and minors. Fur-
thermore, prio r field studies by HRTBT Medical Solu -
tions GmbH suggest that around 15 % of patie nts reject
participation and around 30% of the remainder will not
finalize all follow-u p surveys despite reminder s and ac-
tive follow-up efforts. Consequently, we expec t to rea ch
a sample size of around 10,500 participants having com-
pleted all follow-ups. This number is not yet adjuste d
for people without direct or indirec t access to the inter-
net or other techn ical constraint s, but increasin g case
volumes compared with 2018 are expec ted to balance
this effect.
Furthermore, it is expecte d that insurance claims data
for patients insured in the two participating sickness
funds (abou t 2700 patie nts) can be obtain ed, resulting in
a sample size of 2700 for our primary endpo int. If we as-
sume a statistical difference in effect betw een the inter-
vention and control groups of 0.15 standard deviatio ns,
an error probability of less tha n 5%, and a power of 80%,
a sample size of only around 1400 patien ts with insur-
ance claims data is required for analysis.
Eligibility criter ia
Eligible for this study are all patients with primary elect-
ive TKR and THR above the age of 18 having a sched -
uled surgery or pre-surgery visit betw een Octobe r 2019
and September 2020. Exclusion criteria for part icipation
are emergencies (e.g., femoral fracture), patien ts with
American Societ y of Anes thesiologists classif ication 4 – 6
(4: a patient with a life-threaten ing disease, 5: a mori -
bund patient who is unlikel y to survive without surg ery,
6: a deceased patient with con firmed brain death or an
organ donor), and patients younger tha n 18 years.
Kuklinski et al. Trials (2020) 21:322 Page 3 of 10

Additionally, for practic al reasons, patien ts without dir-
ect or indirec t access to an e-mail account are excluded
from the study. E-mail addresses from relatives are ac-
cepted. All patien ts who deny participation will not be
included in the study.
Informed cons ent
All patients with a primary elective TKR or THR will be
approached by their correspon ding study assista nts for a
p a t i e n tb r i e f i n go n c et h e yh a v e been scheduled for surgery
in the corresponding hospital. Patients will be informed by
either the study assistant or the corresponding physicians
of the study and its benefits, r is ks, and design. Additionally,
they are handed a comprehensive study information docu-
ment. Befor e patients are incl uded, they are requ ired to sign
an informed consent form for th eir stu dy part icip ation
(Supplement 1 ). The informed consent allows us to contact
the patient via e-mail, post, and telephone and to process
and link the patient ’ s data from different sources during
and after the study.
Patients are aske d to sign two addit ional consent
forms: (a) one for processing the ir hospital administra -
tive data and (b) one for process ing their insurance data
in case the patient is con tracted with one of the partici-
pating sicknes s funds. Both of these consent forms are
optional an d are not required to participate in the study.
Pati en ts will be free to wi thdr aw from ei ther on e of the
thre e co nsen ts wi th out st ati ng a re aso n. If th e pati en ts
with dr aw fr om the co nsen t fo r part ici pa tio n, all th ei r data
wil l be delete d. Pa tien ts are al lowe d to part ici pate in oth er
st udie s as long as th ese do no t int erfe re wi th our st udy.
Participant timel ine
Each participant will be participa ting in the stud y for a
maximum of 12 months plus the duration of the hospital
stay, startin g with the admission day followe d by the in-
patient stay and the discharge and post-discharge period .
The participant will have to answer two questionna ires
during the hospit al stay: at admission and discharge. At
discharge, the randomized allocation into the interven -
tion and control groups takes effect, and the participant
is followed up with electronic question naires eith er one
or fo ur tim es in the 12 mont hs after hospi tal disc harg e.
With the fi nal ques tion nai re af ter 12 mo nths , the stud y
wil l conc lud e for each pa rti cipa nt re gard les s of all ocat ion .
The ti m eline for the pa rti cipa nt s is pr esen ted in Fig . 1 .
Baseline asses sment
Baseline assessment takes place for all eligible partici-
pants at the day of admission into the hospital. The timing
differs slightly between the s tudy centers. Three study cen-
ters perform the baseline assessment during their pre-
surgery examination days; this can be up to 6 weeks before
surgery. After giving informe d consent, the participant will
be included in the study by providing name and e-
mail address. In the next step, while waiting for the
physician ’ s appointment, the participant is given a
tablet to respond to a 10- to 15-min questionnaire
co ns is t in g of bas ic dem o gr ap h ic , c om or b id it y i nf or m a-
tion, and selected PROM sets.
The overal l questionnaire is based on the ICHOM
(International Consor tium for Health Outc omes Meas-
urement) Stan dard Set for Hip and Knee Oste oarthritis,
which consists of the EQ-5D-5L, HOOS -PS/KOOS-PS,
and an analogue pain scale . This set was refined by add-
ing the PROMIS Depression and Fatigu e sets, as stud ies
show that the recovery pro cess is also af fected by pa-
tients ’ mental conditions [ 15 ]. During selec tion of the
PROM sets, thre e criteria were of utmost imp ortance.
First, the questionnaire shou ld be brief to inc lude it in
the hospital ’ s daily activities. Second, the sets should be
renowned and pro ven by literatu re. Finally, the com-
bined set of PROMs should cover all importa nt patient-
related aspects of the osteoarth ritic condition and the
elective TKR and THR procedures: health -related quality
of life, functionali ty, pain, and mental condition.
At di sc harg e fr om th e ho spi ta l, th e pa rti cipa nt o nce
again is handed a tablet to c omplet e – alone or with the
help of the stud y as sistant – a mostly identical question-
naire (omit ting demographic and comorbidity questions).
Besides d ocumenting the data from t he quest ionnaire, the
study assist ant will document add itional parameters at
admission, after surgery, and at discharge, encapsulating
information on the part icipant ’ s medical hist ory, th e sur -
gery, and aftercare. In Fig. 1 , th e st anda rd pro to co l ite ms at
di ffe ren t p oi nt s i n ti me a re sh own .
Randomization and blinding
The allocation of participants occurs after completion of
the patient survey at the day of discharge; thus, during
inpatient stay, all eligible patients are treated equally. All
participants are stratif ied into patien ts with TKR or
THR and then random ly allocated at a ratio of 1:1 into
the interventio n or control group. No further stratif ica-
tions or corrections are performe d. Owing to data
security regulat ions, randomiza tion will be carried out
for each hospital individua lly. Figure 2 shows the
randomization flow. The stud y ’ s software provider will
be responsibl e for the random ization algorithm, and al-
location will be show n to the study assi stant or the phys-
ician only after discharge of the participant. Hence ,
during the inpatient stay, the hospital staff and the par-
ticipants are blinde d. The participants will stay blinde d
until the end of the study, not knowing whethe r they are
in the interventio n or control group. Frequ ency of the
surveys is not disclosed to patients, in either the inter-
vention or con trol group.
Kuklinski et al. Trials (2020) 21:322 Page 4 of 10

Intervention
Whereas participa nts in the control group will be asked
to complete only a final follow-up questionna ire 12
months post-dis charge, participant s in the inte rvention
group have to comple te four follo w-up questionna ires:
at months 1, 3, and 6 an d a final follow-u p 12 months
after discharge. All follow-up questionnaires are sent via
e-mail and are answered electronic ally by the partici-
pants on their computers, smar tphones , or tablets. In
case the participants do not have an e-mai l account, e-
Fig. 1 Standard protocol items – PROMoting Quality
Kuklinski et al. Trials (2020) 21:322 Page 5 of 10

mails are sent to relatives if agreed upon and jointly
filled out by relative and patient. Results from the ques-
tionnaires will be autom atically transferred to the study ’ s
software an d are observable by the hospitals ’ study assis-
tants and physician s; 1-, 3-, an d 6-month PROM set
scores will then be screened for critical values or un-
favorable develo pments.
When critica l values or deve lopments are detected, the
software alerts the study assistants of the corresponding
hospitals and an interv ention is initiate d. Interventions
are characterized by three steps. Fir st, the stud y assistant
sends a sta ndardized repor t to the participant , via post
or e-mail, where critica l values and developments are
highlighted and a follow-up call is announced. Second,
the study assistant calls the participants by phone to in-
form them of the critical values, asking permis sion to
forward the PROM results to their outpatient specialist
or gene ral prac titi oner and re comm endi ng a v isit to th eir
phys ician to po tent ially ad just th e treatm ent. Fi nall y, a re-
port wi th the part ici pant ’ s re sul ts will b e fo rwar de d, by
post or fax , to th e outpa tient ph ysici an. In the ne xt re gula r
ques tionn aire, pa rtic ipa nts ar e as ked to re port ch ange s in
thei r trea tmen t schedu le in or der to docum ent mo difica -
tio ns in the ou tpat ient ph ysici ans ’ tr eatmen t with re spec t
to phys ioth erap y, med ica tion , or surg ery.
For he alth -rel ated qu alit y of life (E Q-5D -5L ) and fu nc-
tio nali ty (KOOS -PS and HOOS -PS ), cr iti cal abso lute
val ues an d unfa vor abl e devel opme nt in the re cove ry paths
were de fined b y an expe rt cons ortium of 13 or thoped ic
phys ician s, repr esen ting al l nine part icipa ting hosp itals .
For thi s defi niti on, th e stan dard Del phi tech niqu e was
de ploy ed. Th e ad vant age of the stan dard De lph i tech niqu e
is that it off ers a stru ctur ed pro cess of co llec ting expe rt
opin ions, ap proach ing cons ensu s, with out bei ng bias ed by
the do mina tion ef fect of a fe w expe rt s in open di scus sio ns
[ 16 ]. The ph ysic ians se para te ly popu late d te mpl ates f or
each i tem of the PROM sets – EQ -5D -5L (f or hi p and
knee ) an d KOOS- PS/HO OS- PS at 1, 3, 6, and 12 mont hs
afte r surger y – subj ect to an sw erin g the fo llowin g ques-
tio n: “ Wh ich pa tien t value of th is part icul ar item woul d be
cons idere d cri tica l at 1, 3, 6, o r 12 mont hs afte r su rger y to
sche dule an appo intm ent fo r a fo llow -up exam ina tion ? ”
Results wer e collected in one -on-one interview s, con-
solidated, and analyzed, an d basic sta tistics were played
back to the physicians, offering them the chance to ad-
just their values. Feedback was collected and once again
consolidated, and results were played back and discussed
in a final joint call. Moreover, it was agreed that nei ther
the EQ-5D-5L nor KOOS-PS/HO OS-PS scores should
worsen over time. Defi ned values have additiona lly been
sanity-checked on histori c values of patients of two par-
ticipating stud y centers in order to test their sensit ivity.
For the PR OMI S Fati gue and Depr essi on scor es, on ly
abso lute cr itica l value s were se t on the ba si s of ex isti ng
re sear ch; fo r exam ple, a cr iti cal PR OMI S Depr essi on scor e
was se t to the PHQ- 9 (Pat ient Heal th Questi onnai re -9)
cl assi fica tion of “ mode ra tely se vere ” depr ession [ 17 ]. All
cr itic al val ues ar e summar ized in Tab le 1 .
Data quality enhancement
Each study assistan t is provi ded with a digita l dashbo ard
showing open tas ks, critical value alerts, and patien ts ’
Fig. 2 Randomization process
Kuklinski et al. Trials (2020) 21:322 Page 6 of 10

activity related to receiving and answering follow-u p
questionnaires. Each task is associa ted with a deadline,
and a color code reminds the stud y assistant of open
tasks. For the purpose of data comple teness, the partici-
pants will be reminded by the softwa re to fill in their
follow-up questionna ires 1, 2, and 7 days after the initia l
follow-up question naires are sent out. If a participant
has not compl eted the que stionnaire af ter three re-
minders, the study assistan t will call to support him or
her.
Moreover, predefined standardized e-mails, guidelines for
the follow-up s, and intervent ion calls ensure consistency
between study centers. Furth ermore, adher ence to the
protocol given in the study design was promoted in training
on the ground and duri ng a central workshop for all study
assistants and physicians.
Hospital administrative data, clinical quality data, and
insurance claims data
Afte r comp leti on of th e last pa rti cipa nt ’ s qu esti onnai re
and onl y for those wh o have give n cons ent, ho spi tal ad-
mini stra tive da ta an d i nsur ance cl aim s da ta will be adde d
to th e part ici pant s ’ PR OM da ta. Ho spi tal ad minist rati ve
da ta are pr ovide d by the ho spi tal s ’ co ntro lling de part ment
on th e basis of th e hosp ita l inte rnal ca se numb er of th e
pa tien t. In sura nce cl aims da ta are pr ovi ded fo r part ici-
pa nts wh o are in sure d at one of th e partic ipati ng si ckne ss
fund s and hav e give n cons ent.
Outcomes
The ov eral l aim of th e study i s to te st the co st-
effe ctiv enes s of PROMs fo r early i dent ifi cati on and ther e-
fore ti mely trea tment of post -sur gica l compl icat ions or
the he alth- relat ed qu alit y decr easing de vel opme nt s or
both . The pr ima ry en dpo int o f the st udy i s to in vest igate
cost -effe ctive ness an d thus the opti miza tion of outc ome
qual ity comp ared wi th th e reso urce utili zati on of the de -
sign ed int erve nti on acro ss the path way. Outc ome qual ity
is de fine d as a comp osi te meas ure of PR OMs an d cli nica l
outc ome meas ures su ch as re-op er ation s. Util ized
re sour ces ar e dire ct and in dire ct follo w-up he alth -car e
cost an d the cost of imp lement ing the desi gn ed
inte rven tio n.
Second ary outcome s include the improvement of the pa-
tients ’ functionality reflected by the KOOS-PS/HOOS-PS;
of medium- to long-term health-related quality o f life eval-
uated by the EQ-5D-5L; of pain in knee, hip, and lower
back; of satisfaction with treatment outcome (measured
through selected questions from the Patient Experience
Questionnaire, or PEQ); and o f clinical outcome measures
such as post-operative revision and re-operation rates. Fur-
thermore, these analyse s will be repea ted with subgroups.
Specific analyses will be carried out to estimate the impact
of enhanced recovery programs or the choice of a specific
implant on patient-reported outcome quality, for example.
Statistical analys is
Data wi ll be provi ded in el ectr onic form at s. A stat istica l
anal ysis pr ogram wi ll be us ed to ru n test s and an alys es .
For th e plan ned st atis tica l analys es, it has to be dist in-
gui sh ed betw een th e prim ary an d the seco ndar y outco me.
For primary outcom e – the cost -effectiveness of using
PROMs in TKR /THR – a cost -effectiveness analysis
(CEA) will be conducted . In the CEA, altern atives will
be evaluated by costs and consequences (qua lity im-
provement) and mapped on a cost- effectiveness plane
[ 18 ] and thus create support for later policy recomm en-
dations. For cost s, the cross-sectoral sickn ess funds ’
claims data on the patien t level for di rect and indirect
follow-up costs as well as the cost of the inte rvention
are taken into account to calculate incremental cost. For
the patients ’ overall health status, a compos ite measure
is used. Resu lts for each patient ’ s quality indicator are
gathered, sta ndardized, and com bined into a quality
index. This compos ite mea sure is a forma tive construct
as it is expected that the different quality indicators will
correlate [ 19 ]. In order to test for the rob ustness of the
results, scenario or probabilis tic sensit ivity analyse s or
both are planned.
For the secondary endpoints, we will ap ply mostly mul-
tiple regressions using the differences in the quality
Table 1 Summary of critical values
PROM Sets Month 1 Month 3 Month 6 Critical developments*
EQ-5D-5L hip 0.37 0.64 0.74 Yes
HOOS-PS 53.00 36.30 27.70 Yes
EQ-5D-5L knee 0.36 0.51 0.70 Yes
KOOS-PS 51.60 43.60 33.60 Yes
PROMIS Depression 65.80 65.80 65.80 No
PROMIS Fatigue 69.00 69.00 69.00 No
Abbreviations : EQ-5D-5L EuroQ oL 5-dimension 5-level, HOOS-PS Hip disability and Osteoarthri tis Outcome Score-Physi cal Function Short-form, KOOS-PS Knee injury
and Osteoarthritis Outcome Score-Physical Function Short-form, PROM Patient-reported outc ome measure, PROMIS Pati ent ‐ Reported Outcomes Measurement
Information System
* Alerts at critic al development defined as worsening score compared with previous questionnaire
Kuklinski et al. Trials (2020) 21:322 Page 7 of 10

indicator outcomes and improve ments between the inter-
vention and control groups. Several subgroup-level analyses
for distinct and relevant patient cohorts will be performed.
Besides others, subgroups w ill cover age, sex, education,
mobilization, comorbidity, and type of prosthesis.
Data management
The co lle cti on, sto rage , and proc essing of pers onal da ta in
thi s stud y are carr ied ou t in acco rdan ce wi th the ap plic-
abl e data pr ote cti on re gula ti ons of th e fede ral st ates i n
conn ecti on with th e Eur ope an Gene ral Data Pr otec tio n
Regu lati on (GD PR) an d take in to acco unt th e spec ific pr o-
vi sion s of the Germ an Soci al Code, Te nth Bo ok (SGB X) .
Duri ng the st ud y, all da ta reco rded electr onic all y or in th e
hosp ital wi ll be st ored at the re specti ve ho spi tal se rver s
and ca n be acc esse d or de cryp ted on ly by au tho rize d user s
in th e ho spital en viron ment. Dat a wi ll be tran sfer red to a
secu red pers ona li zed acce ss SFT P- Serv er of the ev alua ting
inst itute . Ever y auth oriz ed user is as signed to a sepa rate
ar ea on the serv er wher e tr ansp ort- encr ypte d (AES-2 56)
da ta can be sto red an d retr ieved .
All transferred data will be completely pseudonymized.
Consequently, to matc h primary patie nt data to hospit al
administrative data and insurance claims data, a pseudo-
nym will be creat ed by the study ’ s software followin g
UUID (universall y unique identifier) standard and is
added to the patien t data. The pseudon ym will be added
to the hospital administrative data and insurance claims
data. All other identificatio n data will be deleted before
it is transfe rred to the researc hing institute . Pseudony-
mized data will be stored for two years at the research-
ing institute (Tec hnical University Berlin, or TU Berlin)
and stored at study centers for 10 years after the study
completion to ensure fur ther evaluat ion of study results.
This complies with the recommendation for good prac-
tice for secondary data analysis [ 20 ].
Study management
Stud y manage ment is le d by th e proj ect te am at TU
Berl in. Th e ove rall proj ect te am co nsis ts of th e pers on re-
spo nsib le for th e st udy de sign , membe rs f rom th e two pa r-
tici pati ng Germ an sick ness fund s, the tech nica l pr ovide r,
and all st udy as si stan ts. The team meet s on a re gul ar on e-
mont h basis b y teleco nfer ence to di scus s the pro gress an d
sol ve aris ing prob lems. Re gula r one-o n-one ca ll s are con-
duct ed betw een th e TU Be rlin pr oject te am an d st udy as -
sist ants to ensu re that enro llment is i n line with th e study
pro toco l. Additi onal ly, on- site vi si ts are plan ned eve ry 3 –
4 mo nths . Duri ng th ese se ssi ons, st udy ma nage ment wi ll
moni tor ad here nce to th e stud y de sign .
Furthermore, inte rmediate reports with statistics on
recruitment an d follow-up rates are sent to the study
management each month . Regular status upda tes are
sent to the study sponsor. Interme diate reports con tain
only aggregate d data without part icipant-specific data.
After 6 and 12 months, patient data sets will be extracted
from the soft ware to check data quality and consist ency.
Moreover, payo uts to the hospit als are linked to patien t
recruitment rates (bas ed on their internally projected
yearly case volume) and follow-u p completion rates.
Therefore, study assistants need to export statistics at
given points in time to receive full compe nsation. Owing
to the character of the study, no adverse effect s are ex-
pected, but unfavorable developmen ts will initiate an
intervention and be part of the study design.
Discussion
Recent stud ies have show n the value of PROMs in moni-
toring patients ’ recovery paths in oncologi c settings [ 12 ,
13 ] as well as their effect iveness in measur ing patient-
relevant qua lity after TKR /THR [ 7 , 8 ]. However, to the
best of our knowle dge, no RCT has examined outc ome
improvement and cost- effectiveness of monitoring and
intervening in case of critical recovery paths with the
help of PROMs.
Insights
Depending on a positiv e and cost-ef fective impact of the
intervention, a further aim is to evaluate the feasibility of
implementing regular and digitize d PROM -based com-
munication into standard ca re. Furthermore , results
from this study can be leveraged to define and imple-
ment selectiv e contracts betw een sickness funds and
health providers based on quality indicators [ 21 ]. The
setup phase of our study revealed several insights.
Firs t, digiti zed PROM s can be a benef it but also a chal -
le nge to hosp ital s as we ll as pa tien ts . Unfor tunate ly, the
col lect ion of PROM s on pa per has be en no t effe cti ve and
ther e have be en low foll ow-up re turn ra tes and th e burde n
of addi tiona l docu men tati on work fo r hosp ital s. Digit ized
PRO Ms pro mise hi gher re turn ra te s and sign ifi cant ly
re duce d docu men tati on work . Neve rthe less , hospi tal IT
de part ment s ne ed to be coll abor ativ e a nd pers onnel ne ed
to be tr ain ed to fam ilia rize pa tien ts with di gi tal too ls.
Seco nd, stru ctur al chan ges ar e nee ded to enab le seam -
le ss imp lem enta tion of the st udy desi gn. Th e effect ivene ss
of PRO Ms requ ire s acce ptan ce by phys ici ans as wel l as
hosp ital m anag em ent. It coul d be ob serv ed that a mo ve
towa rd pati ent cent ered ness wa s gene rall y perc eiv ed as
very positi ve by ph ysi cian s and stud y assist ants . Neve rthe -
le ss, re sour ces are re qui red for pe rsonn el who fa mili arize
pa tien ts with PR OMs an d thei r rel evan ce in the af terc are
and wh o comp ile th e data . This re lat ionshi p betw een
st udy as sist ant and pa tien t is the ce ntra l lever fo r data
qual ity an d comp lete ness . More over , eff ective com muni -
cati on chan nels be tw een ho spi tal s and o utpati ent ph ysi-
ci ans an d pati ents ar e key fo r the b est po ssib le re cove ry
pa thwa y. Often , this com muni cati on is disr upte d becau se
Kuklinski et al. Trials (2020) 21:322 Page 8 of 10

of th e boun dari es betwe en the si loed in - and out pati ent
sect or in the Germ an heal th- care sy stem .
Third, data privacy and security regulation were
challenging factors in the setup of the study. New data
security regulations complicate the communication
between hospitals, patients, and outpatient physicians.
A common nation-wide heal th data platf orm for col-
lecting data and for communicating results could be
an interesting idea for fur ther discussion.
Lastly, in Germany, there is a d iverse landscape of
hospitals, ranging from full-service providers to spe-
cialized hospitals and specialist outpatient clinics. The
div e rs i ty o f t he s et of hos p it a ls in t h e st ud y s am p le
already indicates that a standardized “ one size fits all ”
process will not work. The collected insights in hind-
sight can be leveraged for further analysi s to define
the degree of standardization in the approach.
Limitations
There are a numbe r of limit ations to the study at hand.
First, owing to data security regulations and complexity,
outpatient physic ians are not forma lly part of the study.
Unfortunately, we can only advise but not oblig e the
outpatient physici ans to use the participants ’ critica l
PROM results in their further treatment plan. We try to
convince them of the study relevance by sending infor-
mation material, directing them to our study websi te,
and thorough con versation with the participa nt. Second,
patients without direct or indirect access to an e-ma il
address cannot be included in the study. We hope to
minimize this effect by involv ing their relatives. Third,
there is no empirical evide nce on critica l PROM values
at specific points in time yet. We have tried to overc ome
this limitation with the forma tion of an expert consor-
tium and a real data chec k. Neverthele ss, the defined
critical values might be over- or underestima ted, thus in-
cluding participant s with non -critical recov ery paths or
missing participants with critical recovery paths.
Fo ur t h, p a rt ic ip a nt s i n th e i nt er ve nt io n g r ou p mi g ht
have a learni ng curve when responding to the follow-
up questionnaires, deliberately avoiding interventions.
Fr om ou r poi n t of v i ew , t hi s ef fe c t i s un lik e ly a s t he
participant does not profit from avoi ding interven-
tions. Finally, differences between study centers i n
personnel, organization, and infrastructure might in-
fluence the patient pathway during ho spital stay des-
pite adherence to the study protocol.
Dissemination
The results of this study will be submitted for publi-
cation in relevant journals, presented in relevant con-
ferences, and used in the po litical discourse. Results
will play a role in conversations with the sickness
funds and the Federal Joint Committee for developing
German-wide implementation. Participating hospitals
will be included in the publications and have the
right for publ ication of their data. All results will be
on an aggregated basis and cannot be connected to
individual participants.
Trial status
The cu rren t pr otoc ol is vers ion 1, da ted Jan uary 15, 20 19.
Recr uitm ent o f pati ents bega n, de penden t on the st ud y
cent er, bet ween Oc tobe r 1 and Ja nuar y 1, 2020 an d will
end ar ound De cem ber 31 , 2020 . The tri al was st ill open at
the ti me of stud y protoc ol su bmi ssi on. T he stud y i s ex-
pe cted to run un til Marc h 31, 20 23.
Supplementary information
Supplementary information accompan ies this paper at https://doi.o rg/10.
1186/s13063-020-04252-y .
Additional file 1. Informed consent.
Abbreviations
CEA: Cost-effectiveness analysis; EQ-5D- 5L: EuroQoL 5-dimension 5-level;
HOOS-PS: Hip disability and Osteoarthritis Outc ome Score-Physical Function
Short-form; KOOS-PS: Knee injury and Osteoar thritis Outcome Score-Physical
Function Short-form; PROM: Patient-reporte d outcome measure;
PROMIS: Patient ‐ Reported Outcomes Measuremen t Information System;
RCT: Randomized controlled trial; THR: Total hip replacemen t; TKR: Total knee
replacement; TU Berlin: Technical University Berlin
Acknowledgments
We thank the orthopedic physicians and study assistant s involved for their
engagement in the design and the study itself; all physicians who were part
of the expert conso rtium for support in defining the critical thresholds; the
study centers Charité, DIAKOVERE Annastift, Helios ENDO-Klinik Hamburg
GmbH, RoMed Kliniken Prien a. Chiemsee, Sana Kliniken Sommerfeld, Schön
Klinik Hamburg Eilbek, Schön Klinik Neustadt, VAMED Ostseeklinik Damp
GmbH, Waldkliniken Eisenberg GmbH for their contributions to carry out this
study and HRTBT Medical GmbH for technically implementing the study de-
sign; Thorben Breitkreuz and Thomas Grobe from the aQua Institute for sup-
porting statistical analyses and power calculations and for proofreading the
document; the sickness funds BARMER and BKK Dachverba nd for their pro-
ject partnership; and Justus Vogel and Jens Deer berg-Wittram for their valu-
able input and support durin g the grant application process. We
acknowledge support by the Open Access Publica tion Fund of TU Berlin.
Authors ’ contributions
DK, LO, CP, and AG were responsible for the study design and methodology.
LO is leading the project administration, and project supervision was
provided by AG, RB, and CP. DK drafted the first version of this article. LO,
CP, RB, and AG provided valuable feedback on the manuscript. All authors
provided critical intellectual input to the manuscript and read and approved
the final version of the manuscript, agreeing to be accountable for all
aspects of the work.
Funding
The study is funded by the Innova tion Fund of the German Federa l Joint
Committee (G-BA) in the stream “ Care mode ls with comprehensive and
measurable results and process responsib ility ” under the funding code
01NVF18016. The funding period is set between Apri l 1, 2019 and March 31,
2023. The funding body was not actively involved in the study design or in
the data collection or analysis or interpretation of the results but rather
acted and will act as a reviewing and monitoring body.
Kuklinski et al. Trials (2020) 21:322 Page 9 of 10

Availability of data and material s
Data sets generated and collecte d by this study will not be publicly
available. Analyses of the collected data will be granted only to the
researching institute, the evaluating institute, and the participating hospitals.
Ethics approval and consent to participate
The study was approved by the lead Charité Ethics Committee, Berlin (EA4/
169/19). Assent was given by the other responsible ethical review
committees (Medical Association Hamburg, Medical Asso ciation Schleswig-
Holstein, Hannover Medical School, Friedrich-Schiller Univers ity Jena, and the
Medical Association Brandenbur g). The study is registered at the German
Clinical Trials Register (DRKS) under DRKS00019916. All potential ly eligible
participants will be approached to offer their informed consent to participate
in the study. Additionally, they can accept to release their hospital
administrative data in an optional consent form. For patients insured by
participating sickness funds, a third consent form is handed out to ask for
permission to process their insu rance claims data at the end of the study
period. Patients will be free to withdraw from either of the three consents
without stating a reason. If the patients withdraw from the consent for
participation, all their data will be deleted.
Consent for publication
Material in this article is not subject to publication restrictions.
Competing interests
CP is contracted full-time with Stryker Corporation, a medic al technology
company that also produc es knee and hip implants. The other authors
declare that they have no competing interests.
Received: 4 February 2020 Accep ted: 13 March 2020
References
1. Statistical offices of the Federation and the federal states. Diagnosis-Related
Groups Statistic 2016, On-Site, Version 0.
2. Pabinger C, Geissler A. Utilization rates of hip arthroplasty in OECD
countries. Osteoarthr Cartil. 2014;22(6):734 – 41.
3. Pabinger C, Lothaller H, Geissler A. Utilization rates of knee-arthroplasty in
OECD countries. Osteoarthr Cartil. 2015;23(10):1664 – 73.
4. Pabinger C, Lothaller H, Portner N, Geissler A. Projections of hip arthroplasty
in OECD countries up to 2050. Hip Int. 2018;28(5):498 – 506.
5. Pross C, Geissler A, Busse R. Measuring, Reporting, and Rewarding Quality of
Care in 5 Nations: 5 Policy Levers to Enhance Hospital Quality
Accountability. Milbank Q. 2017;95(1):136 – 83.
6. Va lde ra s JM, Ko tzeva A, Es pal larg ues M, Guya tt G, Fe rran s CE, Ha ly ard MY , et al.
Th e impa ct of meas urin g pati ent- repo rted ou tcom es in cl ini cal pra cti ce: a
sy ste mati c re vie w of the lite ratu re . Qu al Life Re s. 200 8; 17(2 ):1 79 – 93 .
7. Homm R. Patient-reported Outcomes (PROs) bei Hüft-und Kniegelenkersatz.
In: Klauber J, Dormann F, editors. Qualitätsmonitor 2017. Berlin: Medizinisch
Wissenschaftliche Verlagsgesellschaft; 2017.
8. Gutacker N, Siciliani L, Moscelli G, Gravelle H. Choice of hospital: Which type
of quality matters? J Health Econ. 2016;50:230 – 46.
9. Ba ker PN, D ee han DJ , Lee s D, J am eson S, A very PJ, Gregg PJ, et al . The effe ct
of su rgic al fact or s on ear ly patie nt-r epor te d outc ome mea sure s (PRO MS )
fo llo wing to ta l knee rep lace ment . J Bone J oint Su rg Br. 20 12; 94(8 ):105 8 – 66 .
10. İ mr en Y, Ded eo ğ lu SS , Çaka r M, Ça buk H, Ba yrak ta r TO, G ürbü z H. Inf rapa tel lar
Fa t Pa d Ex cisi on dur ing To tal Kn ee Arth rop last y Did No t Alte r the Pa tel la r
Te ndon Le ngth : A 5-Ye ar Fo llo w-Up Stud y. J Kn ee Su rg . 201 7;30 (5 ):4 79 – 83.
11. Resolution of the Federal Joint Committee on the Acceptance of the Draft
Conceptual Draft of the Institution pursuant to Section 137a of the German
Social Code, Book V for a Quality Assurance Procedure for Discharge
Management; 2017.
12. Ba sch E, Dea l AM, Du eck AC , Sc her HI , Kris MG , Hudis C, et al . Over all Su rv iva l
Re su lts of a Tria l Asse ss ing Pa ti ent- Repo rt ed Outc ome s for Sym ptom
Mo nito ring Du ri ng Rout ine Canc er Tr eat ment . JAMA . 201 7;3 18(2 ):19 7 – 8.
13. Basch E, Deal AM, Kris MG, Scher HI, Hudis CA, Sabbatini P, et al. Symptom
Monitoring With Patient-Reported Outcomes During Routine Cancer
Treatment: A Randomized Controlled Trial. J Clin Oncol. 2016;34(6):557 – 65.
14. Busse R, Blümel M, Knieps F, Bärnighausen T. Statutory health insurance in
Germany: a health system shaped by 135 years of solidarity, self-
governance, and competition. Lancet. 2017;390(10097):882 – 97.
15. Singh JA, Lewallen DG. Depression in primary TKA and higher medical
comorbidities in revision TKA are associated with suboptimal subjective
improvement in knee function. BMC Musculoskelet Disord. 2014;15:127.
16. Jairath N, Weinstein J. The Delphi methodology (Part one): A useful
administrative approach. Can J Nurs Adm. 1994;7(3):29 – 42.
17. Choi SW, Schalet B, Cook KF, Cella D. Establishing a common metric for
depressive symptoms: linking the BDI-II, CES-D, and PHQ-9 to PROMIS
depression. Psychol Assess. 2014;26(2):513 – 27.
18. Rudmik L, Drummond M. Health economic evaluation: important principles
and methodology. Laryngoscope. 2013;123(6):1341 – 7.
1 9 . Shwartz M, Res tuccia JD, Rosen AK. Com posite Measures of Health Care P rovider
Performance: A Description of Appr oaches. Milbank Q. 2015;93(4):788 – 825.
20. Swart E, Gothe H, Geyer S, Jaunzeme J, Maier B, Grobe TG, et al. Gute Praxis
Sekundärdatenanalyse (GPS): Leitlinien und Empfehlungen.
Gesundheitswesen. 2015;77(2):120 – 6.
21. Quality contracts according to § 110a SGB V - Evaluation concept for
investigating the development of quality of care according to § 136b para.
8 SGB V; 2017.
Publisher ’ sN o t e
Springer Nature remains neutral with regard to jurisdic tional claims in
published maps and institutional affiliatio ns.
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