STUDY PROTOCOL Open Access
Impac o imp o ed eco ding o wo k-
ela edness in p ima y ca e isi s a
occupa ional heal h se ices on sickness
absences: s udy p o ocol o a andomised
con olled ial
Salla A kins
1,4*
, Ulla Ojajä i
2
, Nina Talola
1
, Me i Viljamaa
2
, Jaakko Ne alainen
3
and Jukka Ui i
1
Abs ac
Backg ound: Employmen p o ec s and os e s heal h. Occupa ional heal h se ices, pa icula ly in Finland, ha e a
cen al ole in p o ec ing employee heal h and p e en ing wo k abili y p oblems. Howe e , p ima y ca e wi hin
occupa ional heal h se ices is cu en ly unde used in in o ming p e en i e ac i i ies. This s udy was designed o
assess whe he he eco ding o wo k abili y p oblems and imp o emen o ollow-up o wo k- ela ed p ima y ca e
isi s can educe sickness absences and wo k disabili y pensions a e 1 yea .
Me hods/design: A p agma ic ial will be conduc ed using pa ien elec onic egis e s and egis e s o he cen al
pensions agency in Finland. Twen y- wo occupa ional heal h cen es will be andomised o in e en ion and con ol
g oups. In e en ion uni s will ecei e aining o imp o e eco ding o wo k abili y illnesses in he p ima y ca e se ing
and imp o ed ollow-up p ocedu es. The in e en ion impac will be assessed h ough examining a es o sickness
absence ac oss in e en ion and con ol clinics as well as be o e and a e he in e en ion.
Discussion: The ial will de elop knowledge o he in e en ion po en ial o p ima y ca e o p e en ing wo k disabili y
pensions and sickness absence. The use o ou ine pa ien egis e s and pensions egis e s o assess he ou comes o a
andomised con olled ial will b ing o wa d ial me hodology, pa icula ly when using egis e -based da a. I success ul,
he in e en ion will imp o e he quali y o occupa ional heal h ca e p ima y ca e and con ibu e o educing wo k
disabili y.
T ial egis a ion: ISRCTN Regis y e e ence numbe ISRCTN45728263. Regis e ed on 18 Ap il 2016.
Keywo ds: Occupa ional heal h ca e, Sickness absence, Wo k abili y, Clus e andomised ial, Elec onic pa ien egis e s
Backg ound
The e is a s ong ela ionship be ween employmen and
heal h. Full- ime employmen p o ec s and os e s heal h
[1–3]. The bene icial e ec s o wo k on pe cei ed heal h
s a us and quali y o li e can be seen e en a e e-
employmen a e a pe iod o unemploymen [4]. Be-
cause o he impo ance o wo k o bo h indi idual
well-being and heal h, along wi h na ional p oduc i i y,
i is impo an o ensu e ha indi iduals a e heal hy,
main ain hei wo k abili y and a e able o pa icipa e in
he wo k o ce. Main aining wo k abili y, howe e , is no
a simple p ocess. The e a e se e al iden i ied isk ac o s
o wo k disabili y, including wo k cha ac e is ics [5, 6];
uns able jobs and unemploymen [7]; a numbe o
ch onic diseases [8]; sickness absence a es [9]; and some
pe sonal cha ac e is ics, such as socioeconomic cha ac-
e is ics [6], educa ion le el [10], gende [11] and age
[10]. Mos o hese isk ac o s o wo k disabili y a e e-
la ed o wo kplace cha ac e is ics [12], and employe s
* Co espondence: [email p o ec ed]
1
Facul y o Medicine and Li e Sciences, Uni e si y o Tampe e, Tampe e,
Finland
4
Depa men o Public Heal h Sciences, Ka olinska Ins i u e , S ockholm,
Sweden
Full lis o au ho in o ma ion is a ailable a he end o he a icle
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A kins e al. T ials (2017) 18:352
DOI 10.1186/s13063-017-2076-3
can in luence hese ac o s by leade ship, o ganisa ional
changes and wo king a angemen s [13]. Fo e ec i e ac-
ion, he employe needs collabo a ion wi h occupa ional
heal h se ices (OHS) ha can p o ide in o ma ion e-
ga ding he ea ly signs o wo k disabili y. Collabo a ion
wi h OHS can con inue om ea ly signs o wo k disabili y
o managing ongoing wo k disabili y, such as by modi ying
wo k asks o suppo ing e u n o wo k [14].
Wo k abili y is a cen al issue in Finland because 7.5%
o he wo king popula ion e i e ea ly on disabili y pen-
sions, which also lowe s he a e age e i emen age [5]
and p oduc i i y. In Finland, OHS moni o and main ain
employee wo k abili y and h ough a ious ac i i ies o
p e en wo k disabili y and o he wo k- ela ed heal h
p oblems [15]. The wide manda e o OHS is possible be-
cause all employees a e equi ed o ha e p e en i e
OHS by law, and app oxima ely 80% o he wo king
popula ion also ecei e p ima y ca e se ices h ough
OHS. In es men s in OHS ha e esul ed in bene i s o
o ganisa ions and hei employees, such as educ ion in
sick lea e [16] and inc eased p o i abili y [16, 17]. In e-
cen yea s, disabili y pension a es ha e also declined
[18]. In Finland, OHS a e an impo an p o ide o
heal h ca e, pa allel o he p i a e and public sec o s
[15]. OHS a e a a key posi ion o os e ing employees’
wo k abili y because hey see employees du ing bo h
p e en i e and cu a i e ac i i ies.
Though p og ess has been made in educing wo k dis-
abili y, mo e wo k is needed in his a ea, and OHS po-
en ial in his espec is unde used. The e is insu icien
in o ma ion abou he ex en , impac and ac ions aken,
based on assessmen s o wo k abili y o diagnoses’wo k-
ela edness du ing hese isi s. O e hal o he causes o
hese isi s a e wo k- ela ed (27% caused by wo k and
52% impai wo k abili y) [19], bu his in o ma ion is
a ely used in p e en i e ac i i ies because elec onic e-
co ds do no allow o p ecise collec ion and use o his
in o ma ion. In e ening in wo king condi ions om he
p ima y ca e se ing could con ibu e o imp o ing em-
ployee wo k abili y and educing disabili y [20].
The ial desc ibed in his a icle is a mul i-cen e,
p agma ic, pa allel-g oup, clus e andomised con olled
ial using elec onic heal h eco ds and pension egis-
ies o imp o e he eco ding o wo k- ela edness and
impac on wo k abili y o p ima y ca e isi s and ul i-
ma ely he ollow-up o hese cases a OHS uni s in
Finland. We ollow he s anda dised S anda d P o ocol
I ems: Recommenda ions o In e en ional T ials
(SPIRIT) checklis in his epo (Addi ional ile 1).
Aim 1
Ou i s aim in he p esen s udy is o assess he e ec
o an in e en ion o imp o ing eco ding and ollow-
up o pa ien p ima y ca e isi s in occupa ional heal h
ca e on medium-leng h sickness absence. Ou hypo h-
esis is ha imp o ed eco ding o wo k- ela edness and/
o e ec s on wo k abili y du ing p ima y ca e isi s and
close ollow-up and ini ia ion o ac ions in ol ing he
pa ien and employe a he wo kplace will educe
medium-leng h (4–9 days) sickness absences.
Aim 2
Ou second aim in he p esen s udy is o assess he
e ec o an in e en ion o imp o e he eco ding and
ollow-up o p ima y ca e isi s o OHS on wo k dis-
abili y pensions as eco ded in he cen al pensions
egis e and long- e m sickness absence (9–60 days) as
eco ded in elec onic pa ien egis e s. We will also in-
es iga e he impac o he in e en ion on sho - e m
(1–3 days) sickness absences. Ou hypo hesis is ha
close pa ien ollow-up will enable he occupa ional
heal h (OH) and employe eams o add ess wo k abil-
i y p oblems ea lie and hus educe sickness absences
and disabili y pension a es.
Resea ch ques ion
Does an in e en ion o imp o e eco ding and ollow-
up o p ima y ca e isi s’wo k- ela edness and hei
impac on wo k abili y educe medium-leng h sickness
absences (4–9 days) mo e han no in e en ion when
measu ed a e 1 yea ?
Me hods/design
T ial design
The ial is a mul i-cen e, pa allel-g oup, p agma ic su-
pe io i y, clus e andomised con olled ial o 1 yea in
du a ion. Each OH uni ep esen s one clus e . Because
he in e en ion is p o ided o doc o s esponsible o
mul iple pa ien s and mul iple employe o ganisa ions, a
clus e design was chosen o dec ease con amina ion
bias. The s udy design was de eloped in acco dance wi h
he SPIRIT guidelines checklis .
Se ing
The s udy was de eloped oge he wi h Pihlajalinna
Työ e eys, an OHS p o ide ha is pa o a p i a e
conso ium. A he ime o ial ini ia ion, he p o ide
has 22 OH uni s in di e en ci ies and owns ac oss
Finland, which oge he had app oxima ely 67,000 em-
ployees on hei clien lis s a he end o 2015. In
Finland, app oxima ely 91% o all employees a e wi hin
he emi o OHS [21], app oxima ely 86% o whom
ha e company-p o ided p ima y ca e se ices, wi h he
es ecei ing legisla i e p e en i e se ices.
Pa icipan s and ec ui men
Each OH uni wi hin Pihlajalinna Työ e eys had be-
ween 500 and 9000 employees on hei egis e . In he
A kins e al. T ials (2017) 18:352 Page 2 o 8
s udy, each clus e is conside ed an independen uni .
All OH uni s in he conso ium wi h ull- ime OH s a
we e selec ed o he s udy. Two cen es wi hin he same
own as a la ge cen e wi h pa - ime OH s a we e le
ou o he s udy. The in e en ion aining was consid-
e ed ou ine s a aining. Employees on he egis e o
he OHS in 2015–2017 be ween he ages o 18 and
65 yea s will be included in he analysis. The coho will
be open, and employees a e eligible i hey join he OH
egis e a any ime du ing he s udy pe iod. An em-
ployee isi ing any o he 22 OH uni s we e conside ed
eligible o analysis.
Randomisa ion and alloca ion
To alloca e OH uni s in o in e en ion and con ol
g oups, a andomisa ion p ocess using dynamic alloca-
ion (speci ically minimisa ion) was used. This me hod
was i s p esen ed by Ta es [22] and la e by Pocock
and Simon [23]. The use o minimisa ion has inc eased
in ecen yea s [24], and i has been sugges ed as he
‘pla inum s anda d’o ials [25] because i allows o
balance be ween ea men and con ol a ms. In his
ial, we conside ed he ollowing as po en ial con-
ounde s and included hem in he minimisa ion: (1) he
clien olume o he OHS sepa a ed in o h ee en e p i-
ses—small, medium and la ge, (2) he main sec o o he
OHS clien s (indus y s o he s) and (3) whe he one o
he OHS uni ’s en e p ise clien s was a majo pape ac-
o y o no ( he pape ac o y had ins i u ed la ge-scale
OH in e en ions in ecen yea s).
We began he andomisa ion wi h simple andomisa-
ion conduc ed by he eam s a is ician (NT). We allo-
ca ed he i s ou uni s h ough simple andomisa ion
(1:1) using he andom numbe gene a o in he R p o-
g am (R Founda ion o S a is ical Compu ing, Vienna,
Aus ia). Fo he emaining 18 uni s, we used minimisa-
ion o alloca e each OHS uni o ei he he ea men
g oup o he con ol g oup o minimise he o al imbal-
ance o po en ial con ounde s, con inuing wi h a 1:1 a-
io. Because he in e en ion was embedded in ou ine
p ac ice, alloca ion was concealed om pa icipan s bu
no om p o ide s o in es iga o s. The conce n o lack
o blinding du ing he minimisa ion p ocess did no
apply in his case, owing o he clus e -based design and
he ac ha bo h he in e en ion and con ol clus e s
a e pa o Pihlajalinna Työ e eys.
Assessmen poin s
Baseline in o ma ion will be assessed o 1 yea p e-
ceding he in e en ion, om 1 May 2015 o 1 May
2016. App oxima ely 72,000 spells o sickness absence
we e egis e ed among 25,000 clien s a Pihlajalinna
Työ e eys in 2015. Fo he p ima y ou come (mean
sickness absence o medium leng h a e he in e en ion
compa ed wi h baseline), assessmen will be conduc ed by
NT a e 1 yea o he in e en ion, using da a up o 1
May 2017 (see Fig. 1 o ial low and Fig. 2 o SPIRIT
diag am). Fo mean disabili y pensions pe cen e, he
ime will be inc eased o 31 Decembe 2017, wi h subse-
quen analysis hoped o a e mo e unding is ecei ed.
In e en ion
All uni s we e in o med o he ongoing esea ch and i s
aims be o e he s a o aining. In he in e en ion
g oup, all doc o s and nu ses o o he OH p o essionals
who a e pa o in e en ion uni s ook pa in aining
p o ided by Pihlajalinna Työ e eys. The in e en ion
aining s a ed on 1 May 2016. The aining las ed ap-
p oxima ely 1 h. Du ing he aining, he p inciple o he
in e en ion was explained, and all pa icipan s ecei ed
w i en ins uc ions on he eco ding p ocedu e and
in e en ion p ocesses. When physicians o nu ses we e
absen , a ollow-up isi o phone call was made o im-
pa he in e en ion in o ma ion. Each physician and
nu se esponsible o a company’s OHS ook esponsibi-
li y o hei companies’employees’ ollow-up. The im-
plemen a ion o he in e en ion was ollowed by he
Pihlajalinna Työ e eys aine , who ollowed up wi h
nu ses and physicians and in i ed hem o pe sonal dis-
cussions on he p ocess as necessa y.
Figu e 3 de ails he in e en ion and pa icipan low.
The in e en ion was designed o i s es ima e he ela-
ionship o he main o addi ional diagnosis o he isi
eason o wo k. Du ing each p ima y ca e isi , he a -
ending physician would assess i s ly whe he he diag-
nosis was ela ed o wo k. Secondly, he clien ’s isko
applying o a wo k disabili y pension was es ima ed
acco ding o ou ca ego ies: (1) no isk o wo k disabili y
pension, (2) less han 50% chance o wo k disabili y pen-
sion in he nea u u e (2–5 yea s), (3) mo e han 50%
chance o wo k disabili y pension in he nea u u e (2–5
yea s) and (4) immedia e isk o wo k disabili y pension.
This assessmen is en e ed in Pihlajalinna Työ e eys’s
elec onic pa ien egis e . Once weekly, all pa ien s a e
ecalled on he elec onic sys em o whom a eco d o
wo k- ela edness was made. Each case is hen assigned o
he OH nu se esponsible o he pa ien ’semploye ela-
ions. The esponsible OH nu se hen ini ia es ollow-up
isi s as app op ia e. These can include wo ksi e isi s;
ipa i e nego ia ions be ween he OH physician, em-
ployee and employe ; occupa ional physio he apy o he
employee; occupa ional psychologis s’assessmen s; o di -
e en kinds o ehabili a ion p ocesses a an indi idual
le el. When a clien is deemed as a g ea e han 50% isk
o wo k disabili y, a sepa a e ehabili a ion plan will be
comple ed wi h he clien p esen . This plan will include
de ails on he clien ’s heal h s a us, planned ac ions o
ehabili a ion, and ollow-up by he OH p o essionals.
A kins e al. T ials (2017) 18:352 Page 3 o 8
Fig. 2 SPIRIT igu e: Summa izes he alloca ion, in e en ions, and ou comes o he s udy
Fig. 1 T ial low diag am. OHS Occupa ion heal h se ices
A kins e al. T ials (2017) 18:352 Page 4 o 8
The con ol g oup did no ecei e addi ional aining
on eco ding wo k- ela edness. I is possible ha Con ol
g oup physicians migh hea o he in e en ion and
migh pay mo e a en ion o assessing po en ial h ea s
o wo k abili y du ing he in e en ion. Howe e , no
cen al in o ma ion is p o ided ega ding he in e en-
ion in he conso ium, and no o malised in o ma ion is
p o ided o con ol uni s, which may educe con ound-
ing. A e he end o he in e en ion, con ol uni s will
be gi en a chance o pa icipa e in aining and imple-
men he in e en ion i he esul s o he in e en ion
we e posi i e. Compliance is checked ia egula con-
ac s by he in e en ion aine wi h he OH uni s,
enqui ing abou implemen a ion and challenges.
Ou come measu es
P ima y ou come
The p ima y ou come is educ ion om baseline o he
mean numbe o medium e m (4–9 days) sickness ab-
sences om he wo kplace pe in e en ion and con ol
cen e a e 1 yea o ollow-up as measu ed by OHS pa-
ien eco ds. We chose medium-leng h sickness ab-
sences as he p ima y ou come o ensu e ha we ha e a
su icien numbe o cases o assess impac . Wi hin he
Pihlajalinna Työ e eys coho in 2015, he e we e
17,794 ins ances o sickness absences be ween 4 and
9 days in du a ion. This ou come is also suppo ed by a
la ge Finnish s udy on o e 6000 municipal wo ke s [26]
which indica ed ha sickness absences o be ween 4 and
9 days we e mo e p e alen (85.7 and 59.0 pe 100
pe son-yea s o women and men, espec i ely) han
hose o e 2 weeks (10+ days) in du a ion. The s udy
also indica ed ha sel -ce i ied (1–3 days) absences
we e he mos common (156.4 and 96.1 pe 100 pe son-
yea s o women and men, espec i ely), bu hese a e
no eliably a ailable om he elec onic pa ien egis e
held by Pihlajalinna Työ e eys. Longe sickness ab-
sences (be ween 2 weeks and 60 days) a e less p e alen
and had a es o 22.8 and 18.0 pe 100 pe son-yea s o
women and men, espec i ely, wi h long absences o
Fig. 3 Pa icipan low diag am
A kins e al. T ials (2017) 18:352 Page 5 o 8

o e 60 days being ela i ely in equen (4.7 and 4.4 pe
100 pe son-yea s o women and men, espec i ely) [26].
Sho e (1–3 days) sickness absences we e no included
as a p ima y ou come, because hey a e no eliably
a ailable om he pa ien egis e , and hey ha e been
ound no o be associa ed wi h disabili y pensions, excep
h ough hei associa ion wi h longe - e m (3+ days) sick-
ness absences [9]. Long (3+ days) sickness absence spells
ha e been ound o be p edic i e o wo k disabili y be o e
he age o 55 [9] and ega dless o heal h s a us [27].
Seconda y ou comes
We will assess he ollowing seconda y ou comes:
1. Reduc ion in mean numbe o sho e m (1–3 days)
sickness absences om he wo kplace pe clus e
om baseline a e 1 yea om he s a o he
in e en ion as measu ed by sel - epo eco ded on
OHS eco ds o OHS eco ds o sickness absence
2. Reduc ion o mean numbe o any o m o wo k
disabili y pensions as measu ed by an employee
egis e ing as ecei ing a wo k disabili y pension on
he cen al pensions egis e om baseline o up o
2 yea s om he in e en ion as measu ed by he
en y on he cen al pensions egis e
3. Reduc ion o mean numbe o long- e m (9+ days)
sickness absences om he wo kplace pe clus e
om baseline o 1 yea a e he in e en ion as
measu ed by OHS eco ds
Powe calcula ion
The p e-s udy powe and sample size calcula ions o
ou main ou come we e based on da a collec ed in 2015
wi h es ima es o he indi iduals be ween he ages o 18
and 65 om he 22 OH uni s (n= 24,892). The 22 clus-
e s had an a e age size o 2300 indi iduals. We es i-
ma ed he in a-clus e co ela ion coe icien o be 0.05.
We used he n4means unc ion in he CRTSize package
in R [28], which akes in o accoun ha he ou come o
indi iduals canno be assumed o be independen . We
used a wo-sided alpha o 5% o ou p ima y ou come,
he sickness absences o medium (4–9) days, wi h an SD
o 1.5. Wi h 11 clus e s andomised o each a m (assum-
ing 2300 indi iduals pe OHS), he s udy had 91% powe
o de ec a leas a 10% di e ence be ween indi iduals in
he in e en ion and con ol OHS g oups. These calcula-
ions showed ha e en wi h a 20% loss o ollow-up o
missing da a, we would s ill ha e 90% powe o he p i-
ma y analysis.
Da a collec ion
Da a on pa ien isi s o he OHS uni we e collec ed
om a cen al pa ien egis e . Sel - epo ed sickness ab-
sences o be ween 1-3 days a e epo ed by he employe
o he OHS uni . P e-in e en ion da a we e ex ac ed by
he in o ma ion echnology se ice p o ide o Pihlaja-
linna Työ e eys, who p o ided coded and anonymised
pa ien da a, a sepa a e lis o pe sonal iden i ie s and a
code o combining he pa ien da a wi h he pe sonal
iden i ie . The lis o pe sonal iden i ie s was sen o he
Finnish Cen e o Pensions, which holds a egis y o
pensions, including disabili y pensions, o he en i e
popula ion. The Finnish Cen e o Pensions ex ac ed
da a on pensions o he en i e lis o pe sonal iden i ie s
and coded i wi h he same code. The pseudonymised pa-
ien da a and coded pension da a we e sen o he Uni e -
si y o Tampe e. The same p ocess will be epea ed o
da a collec ed du ing and a e he in e en ion.
Da a managemen
The da a om he Finnish Cen e o Pensions and
Pihlajalinna Työ e eys we e combined on he basis o pa-
ien codes a he Uni e si y o Tampe e using R so wa e.
Da a we e kep on a secu e se e , passwo d-accessible
only o he esea ch eam. Da a accu acy will be checked
by e e ing back o he OHS uni s o de ails whe e he e
a e suspec ed e o s in da a en y. The Finnish Cen e o
Pensions egis e sys em checks he da a au oma ically,
and he da a a e ou inely e iewed and co ec ed.
Da a analysis
Da a will be analysed on he in en ion- o- ea p inciple.
All employees egis e ed a a clus e will be analysed as
pa o ha clus e . We will use bo h R and IBM SPSS
S a is ics so wa e (IBM, A monk, NY, USA) o analyse
he da a. We will i s examine he da a using desc ip i e
s a is ics. Be ween-g oup analysis will be conduc ed
using Pea son’s chi-squa e es o Fishe ’s exac es o
ca ego ical da a and S uden ’s es o he Mann-
Whi ney U es o con inuous a iables, depending on
no mali y o a dis ibu ion. The no mali y o he dis i-
bu ion o he a iable will be examined wi h he
Kolmogo o -Smi no es . The in e en ion e ec s o
p ima y and seconda y ou comes will be analysed using
eg ession analysis, logis ic eg ession will be used o
dicho omous ou come a iables, and Poisson eg ession
will be used when he ou come a iable is a coun . In
bo h analyses, we will examine he impac o , and con-
ol o , possible con ounde s. The eg ession analysis
will esul in ORs and a e a ios wi h 95% CIs. The e-
sul s will be conside ed signi ican a p< 0.05. Fo ana-
lysing he di e ences in du a ion o sickness absences,
we will use Kaplan-Meye su i al cu es and he log-
ank es .
Da a moni o ing
Because he s udy did no include ulne able popula-
ions, was conside ed no o ep esen a ha m o
A kins e al. T ials (2017) 18:352 Page 6 o 8
pa icipan s, and was conside ed o ha e po en ial o
ou ine p ac ice, we deemed a da a moni o ing commi -
ee unnecessa y.
E hical app o al
E hical app o al was ecei ed om he Pi kanmaa Hos-
pi al Dis ic e iew boa d (Pi kanmaa Hospi al Dis ic
e iew boa d 10/03/2016, e e ence R16041).
Discussion
The weal h o egis e s, especially in No dic coun ies,
allows o inno a i e esea ch o be conduc ed wi h
minimal need o addi ional da a collec ion o ouble
o he pa icipan s. Recen au ho s ha e a gued ha
egis y ials can ha e a weal h o bene i s, bu quali y
issues need o be aken in o accoun [29]. Ou p agma ic
ial uses he combina ion o elec onic heal h eco ds
wi h egis ies and es s a eal-wo ld in e en ion wi h a
good s udy design and maximum ex e nal alidi y [30]
wi h li le dis up ion o he physicians implemen ing he
s udy [31]. The ial is p agma ic in na u e, and hus,
while yielding esul s highly ans e able o o he se -
ings, he e a e s a is ical challenges in design. These in-
clude, o example, he high a ia ion in clus e size,
which may educe he powe . Rega dless o his, we ex-
pec he clus e and o al sample sizes o be su icien o
de ec a ue di e ence, and he impac o he clus e
size a ia ion can be de e mined du ing analysis.
While in e es ing om a me hodological s andpoin ,
he p ac ical impac o quali y imp o emen in occupa-
ional heal h ca e has implica ions beyond his ial and
his pa icula conso ium. Th ough assessmen o wo k-
ela edness o each isi , p ima y ca e isi s can be used
e ec i ely as a ool o seconda y p e en ion and ea ly
in e en ion. These app oaches can be used also in se -
ings whe e occupa ional heal h ca e is no s a u o y.
S udies ha e indica ed ha he eco ding o wo k-
ela edness o isi s is no op imal [32], and app oaches
such as his buil in o se ices could po en ially imp o e
epo ing. Imp o ed epo ing and ecogni ion can also
con ibu e o collabo a ion be ween OHS and employe s
and gene al p ac i ione s [33]. These issues a e impo -
an pa icula ly in Eu ope, whe e he popula ion is age-
ing and li e expec ancy is inc easing and whe e
economic de elopmen depends on a heal hy wo k o ce.
Challenges o he success o he ial can be he scale
o he in e en ion as well as ollow-up ime, which is
sho wi h espec o he ou come o disabili y pensions.
Fu he unding will be sough o ollow his coho o
a longe pe iod. In addi ion, no all sickness absences
can be ex ac ed o all clien s, because clien s may be
gi en sickness absence ce i ica es om he public sec o
o specialised se ices. Changing beha iou on he basis
o one aining isi may be oo op imis ic; physicians
may con inue no o eco d wo k- ela edness o impac
on wo k abili y op imally; in e nal s uc u es may no
suppo collec ing and ollowing up employe isi s; o
employe s may no be eage o in es in employee wo k
abili y. Th ough his andomised ial, we will be able o
assess whe he ou app oach wo ks, and we will conduc
impo an me hodological wo k on using elec onic eg-
is e s o p agma ic ials. Th ough he planned p ocess
e alua ion done alongside he ial, we will be able o as-
sess wha wo ked and wha did no wo k, as well as how
we should modi y he in e en ion in u u e o ensu e
ha suppo ing wo k abili y is a he cen e o p ima y
ca e isi s a occupa ional heal h ca e cen es.
T ial s a us
The ial began on 1 May 2016 and ended on 1 May
2017.
Addi ional ile
Addi ional ile 1: SPIRIT checklis . (PDF 168 kb)
Abb e ia ions
OH: Occupa ional heal h; OHS: Occupa ional heal h se ices; SPIRIT: S anda d
P o ocol I ems: Recommenda ions o In e en ional T ials
Acknowledgemen s
The au ho s acknowledge he pa icipa ion o he occupa ional heal h s a
in he s udy and all he indi idual clien s who a e pa o his s udy.
Funding
The p ojec wi hin which his s udy is conduc ed is unded by he Eu opean
Social Fund ( e e ence numbe S20659). The unde has aken no ac i e ole
in he design, implemen a ion o epo ing o his s udy.
A ailabili y o da a and ma e ials
No applicable.
Au ho s’con ibu ions
JU concep ualised he s udy. MV, NT, JN, UO and SA pa icipa ed in he design
o he s udy. SA, MV and UO coo dina ed implemen a ion o he s udy. SA
w o e he i s d a o he manusc ip and led subsequen e isions. UO, MV
and JN edi ed he manusc ip o in ellec ual con en . NT w o e he sampling
and sample size sec ion wi h con ibu ion by JN. All au ho s con ibu ed o
subsequen d a s o he manusc ip , and all au ho s ead and app o ed he
inal manusc ip .
E hics app o al and consen o pa icipa e
E hics app o al was ecei ed om he Pi kanmaa Hospi al Dis ic E hical
Re iew Commi ee ( e e ence numbe R16041). The need o indi idual
in o med consen was wai ed due o he la ge numbe o pa icipan s and
he non-in asi e na u e o he s udy.
Consen o publica ion
No applicable.
Compe ing in e es s
The au ho s decla e ha hey ha e no compe ing in e es s.
Publishe ’sNo e
Sp inge Na u e emains neu al wi h ega d o ju isdic ional claims in
published maps and ins i u ional a ilia ions.
A kins e al. T ials (2017) 18:352 Page 7 o 8
Au ho de ails
1
Facul y o Medicine and Li e Sciences, Uni e si y o Tampe e, Tampe e,
Finland.
2
Pihlajalinna Työ e eys, Tampe e, Finland.
3
Facul y o Social
Sciences, Uni e si y o Tampe e, Tampe e, Finland.
4
Depa men o Public
Heal h Sciences, Ka olinska Ins i u e , S ockholm, Sweden.
Recei ed: 6 Decembe 2016 Accep ed: 30 June 2017
Re e ences
1. Ross CE, Mi owsky J. Does employmen a ec heal h? J Heal h Soc Beha .
1995;36:230–43.
2. Els ad JI. Inequali ies in heal h ela ed o women’s ma i al, pa en al, and
employmen s a us—a compa ison be ween he ea ly 70s and he la e 80s.
Soc Sci Med. 1996;42:75–89.
3. an de Noo d M, Ijzelenbe g H, D oome s M, P ope KI. Heal h e ec s o
employmen : a sys ema ic e iew o p ospec i e s udies. Occup En i on
Med. 2014;71:730–6.
4. Ca lie BE, Schu ing M, Lö e s FJB, Bakke B, Bo ge s N, Bu do A. The
in luence o e-employmen on quali y o li e and sel - a ed heal h, a
longi udinal s udy among unemployed pe sons in he Ne he lands. BMC
Public Heal h. 2013;13:503.
5. Lahelma E, Laaksonen M, Lallukka T, Ma ikainen P, Pie iläinen O, Saas amoinen
P, e al. Wo king condi ions as isk ac o s o disabili y e i emen : a longi udinal
egis e linkage s udy. BMC Public Heal h. 2012;12:309.
6. Pol inen A, Gould R, Lahelma E, Ma ikainen P. Socioeconomic di e ences
in disabili y e i emen in Finland: he con ibu ion o ill-heal h, heal h
beha iou s and wo king condi ions. Scand J Public Heal h. 2013;41:470–8.
7. Gus a sson K, A onsson G, Ma klund S, Wikman A, Flode us B. Pe iphe al
labou ma ke posi ion and isk o disabili y pension: a p ospec i e
popula ion-based s udy. BMJ Open. 2014;4, e005230.
8. Män yniemi A, Oksanen T, Salo P, Vi anen M, Sjös en N, Pen i J, e al. Job
s ain and he isk o disabili y pension due o musculoskele al diso de s,
dep ession o co ona y hea disease: a p ospec i e coho s udy o 69,842
employees. Occup En i on Med. 2012;69:574–81.
9. Ki imäki M, Fo ma P, Wiks öm J, Halmeenmäki T, Pen i J, Elo ainio M, e al.
Sickness absence as a isk ma ke o u u e disabili y pension: he 10- own
s udy. J Epidemiol Communi y Heal h. 2004;58:710–1.
10. Olo sson T, Pe e sson IF, E iksson JK, Englund M, Sima d JF, Nilsson
JÅ, e al. P edic o s o wo k disabili y du ing he i s 3 yea s a e
diagnosis in a na ional heuma oid a h i is incep ion coho . Ann
Rheum Dis. 2014;73:845–53.
11. Albe sen K, Lund T, Ch is ensen KB, K is ensen TS, Villadsen E. P edic o s o
disabili y pension o e a 10-yea pe iod o men and women. Scand J Public
Heal h. 2007;35:78–85.
12. Joling CI, Bla e BM, Ybema JF, Bonge s PM. Can a o able psychosocial
wo k condi ions and high wo k dedica ion p o ec agains he occu ence
o wo k- ela ed musculoskele al diso de s? Scand J Wo k En i on Heal h.
2008;34:345–55.
13. Kaspin LC, Go man KM, Mille RM. Sys ema ic e iew o employe -sponso ed
wellness s a egies and hei economic and heal h- ela ed ou comes. Popul
Heal h Manag. 2013;16:14–21.
14. an Oos om SH, D iessen MT, de Ve HCW, F anche RL, Schons ein E, Loisel
P, e al. Wo kplace in e en ions o p e en ing wo k disabili y. Coch ane
Da abase Sys Re . 2009;2, CD006955.
15. Ma imo JP, Mäki alo J; Finnish Ins i u e o Occupa ional Heal h. The s a us
o occupa ional heal h se ices in Finland and he ole o he Finnish
Ins i u e o Occupa ional Heal h in he de elopmen o occupa ional heal h
se ices: epo o he in e na ional e alua ion o he Finnish Ins i u e o
Occupa ional Heal h (FIOH). Helsinki: Työ e eyslai os; 2014
16. Baicke K, Cu le D, Song Z. Wo kplace wellness p og ams can gene a e
sa ings. Heal h A (Millwood). 2010;29:304–11.
17. Mille P, Whynes D, Reid A. An economic e alua ion o occupa ional heal h.
Occup Med (Lond). 2000;50:159–63.
18. Sauni R, Ui i J. Uude yöky y ömyyseläkkee o a ähen ynee neljänneksen.
Suom Laaka il. 2015;45:3056–7.
19. Ikonen A, Räsänen K, Manninen P, Rau io M, Husman P, Ojajä i A, e al.
Wo k- ela ed p ima y ca e in occupa ional heal h physician’s p ac ice.
J Occup Rehabil. 2012;22:88–96.
20. Ma imo KP, Va onen H, Husman K, Viika i-Jun u a E. Fac o s associa ed wi h
sel -assessed wo k abili y. Occup Med (Lond). 2007;57:380–2.
21. Kauppinen T, Ma ila-Holappa P, Pe kiö-Mäkelä M, Saalo A, Toikkanen J,
Tuomi aa a S, e al. Työ ja e eys suomessa 2012: seu an a ie oa yöolois a
ja yöhy in oinnis a. Työ e eyslai os: Helsinki; 2013.
22. Ta es DR. Minimiza ion: a new me hod o assigning pa ien s o ea men
and con ol g oups. Clin Pha macol The . 1974;15:443–53.
23. Pocock SJ, Simon R. Sequen ial ea men assignmen wi h balancing o
p ognos ic ac o s in he con olled clinical ial. Biome ics. 1975;31:103–15.
24. Ta es DR. The use o minimiza ion in clinical ials. Con emp Clin T ials.
2010;31:180–4.
25. T easu e T, MacRae KD. Minimisa ion: he pla inum s anda d o ials?
Randomisa ion doesn’ gua an ee simila i y o g oups; minimisa ion does.
BMJ. 1998;317:362–3.
26. Laaksonen M, Ma ikainen P, Rahkonen O, Lahelma E. Explana ions o
gende di e ences in sickness absence: e idence om middle-aged
municipal employees om Finland. Occup En i on Med. 2008;65:325–30.
27. Hul in H, Lindholm C, Mölle J. Is he e an associa ion be ween long- e m
sick lea e and disabili y pension and unemploymen beyond he e ec o
heal h s a us? –A coho s udy. PLoS One. 2012;7, e35614.
28. Ro ondi MA. CRTSize: sample es ima ion unc ions o clus e andomized
ials. 2011. A ailable om: h p://c an. -p ojec .o g/web/packages/CRTSize/
index.h ml. Accessed 15 Aug 2016.
29. Laue MS, D’Agos ino S RB. The andomized egis y ial— he nex
dis up i e echnology in clinical esea ch? N Engl J Med. 2013;369:1579–81.
30. S aa TP, Goldac e B, Gulli o d M, Cassell J, Pi mohamed M, Taweel A, e al.
P agma ic andomised ials using ou ine elec onic heal h eco ds: pu ing
hem o he es . BMJ. 2012;344, e55.
31. Gliklich RE, D eye NA, Lea y MB, edi o s. In e acing egis ies wi h
elec onic heal h eco ds. In: Regis ies o e alua ing pa ien ou comes: a
use ’s guide. Vol. 2. 3 d ed. Rock ille, MD: Agency o Heal hca e Resea ch
and Quali y; 2014. p. 3–22
32. A naud S, Cabu S, Viau A, Sou ille M, Ve ge P. Di e en epo ing pa e ns
o occupa ional diseases among physicians: a s udy o F ench gene al
p ac i ione s, pulmonologis s and heuma ologis s. In A ch Occup En i on
Heal h. 2010;83:251–8.
33. Moßhamme D, Na anzon I, Manske I, G u schkowski P, Riege MA. Coope a ion
be ween gene al p ac i ione s and occupa ional heal h physicians in Ge many:
how can i be op imised? A quali a i e s udy. In A ch Occup En i on Heal h.
2014;87:137–46.
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