In e na ional Jou nal o
En i onmen al Resea ch
and Public Heal h
A icle
In luence o Pue pe al Heal h Li e acy on Tobacco Use
du ing P egnancy among Spanish Women:
A T ans e sal S udy
Ra ael Vila-Candel 1,2 , Es he Na a o-Illana 3,*, Desi ée Mena-Tudela 4, Pila Pé ez-Ros 3,
En ique Cas o-Sánchez 5, F ancisco Ja ie So iano-Vidal 2,6 and Jose An onio Quesada 7
1Depa men o Obs e ics and Gynaecology, La Ribe a Uni e si y Hospi al, FISABIO, C a. Co be a km 1,
46600 Valencia, Spain; a ael. ila@u .es
2Depa men o Nu sing, Facul y o Nu sing and Podia y, Uni e si y o Valencia, Jaume Roig, s/n,
46010 Valencia, Spain; ancisco.j.so iano@u .es
3Depa men o Nu sing, Ca holic Uni e si y o Valencia “San Vicen e Má i ”, Espa e o 7, 46007 Valencia,
Spain; pila .pe ez@uc .es
4
Depa men o Nu sing, Jaume I Uni e si y, A de Vicen Sos Bayna , s/n, 12071 Cas ell
ó
de la Plana, Spain;
[email p o ec ed]
5NIHR Heal h P o ec ion Resea ch Uni (HPRU) in Heal hca e Associa ed In ec ions (HCAI) and
An imic obial Resis ance (AMR) a Impe ial College London, Du Cane Road, London W12 0NN, UK;
[email p o ec ed]
6Depa men o Obs e ics and Gynaecology, Lluis Alcanyis Hospi al, FISABIO. C a Xà i a, s/n,
46800 Valencia, Spain
7
Depa men o Clinical Medicine, Miguel He n
á
ndez Uni e si y, A de la Uni e si a d’Elx s/n, 03202 Elche,
Spain; [email p o ec ed]
*Co espondence: es he .na a o@uc .es
Recei ed: 25 Ma ch 2020; Accep ed: 20 Ap il 2020; Published: 23 Ap il 2020
Abs ac :
Backg ound: Despi e he ac ha obacco use du ing p egnancy p oduces ad e se pe ina al
e ec s, some women con inue o smoke. Heal h li e acy (HL) is essen ial o heal h ou comes in adul s.
Howe e , li le is known abou HL in p egnan women o pos pa um women. The s udy aimed
o analyse he ela ionship be ween he deg ee o HL o women du ing he ea ly pue pe ium and
obacco use du ing p egnancy. Me hods: A mul icen e, desc ip i e, c oss-sec ional s udy was ca ied
ou wi h women in he ea ly pue pe ium in a egion o eas e n Spain, be ween No embe 2017 and
May 2018. Thei HL le el was ob ained using he Newes Vi al Sign (NVS) ool. Mul i a ia e logis ic
models we e adjus ed o es ima e he magni ude o associa ion wi h obacco use in p egnancy. Odds
a ios (OR) we e es ima ed wi h a 95% con idence in e al. Resul s: 193 we e included in he o al.
29.5% (57) o p egnan women smoked obacco du ing p egnancy, wi h a smoking cessa ion a e o
70.1% (40) while p egnan . 42.0% (81) o p egnan women had inadequa e o limi ed HL. A low le el
o HL was s ongly associa ed wi h obacco use, adjus ed by ca chmen a ea and age o i s p egnancy
(LRT p<0.001; ROC cu e =0.71, 95% CI: 0.64–0.79). Conclusion: A low HL is associa ed wi h obacco
consump ion du ing p egnancy. Whe he low HL e lec s he wide cons ella ion o al eady-known
socioeconomic, poli ical and comme cial de e minan s o obacco use, o whe he inco po a ing
HL suppo in e en ions s eng hens obacco cessa ion ac i i ies in p egnancy, wa an s u he
esea ch. S ill, i should be conside ed as essen ial o unde s anding he heal h dispa i ies ela ed o
i s consump ion.
Keywo ds: Heal h li e acy; p egnancy; obacco use; obacco smoking
In . J. En i on. Res. Public Heal h 2020,17, 2910; doi:10.3390/ije ph17082910 www.mdpi.com/jou nal/ije ph
In . J. En i on. Res. Public Heal h 2020,17, 2910 2 o 12
1. In oduc ion
Tobacco use has been iden i ied as he mos impo an cause o p e en able dea h, ad e sely
a ec ing he ca dio ascula and espi a o y sys ems and pe ina al heal h [
1
]. The Wo ld Heal h
O ganisa ion ad ises p egnan women o abs ain om obacco use as he e is no sa e h eshold [
2
].
Indeed, di e en au ho s ha e epo ed ha obacco use p oduces a wide ange o ad e se pe ina al
ou comes such as he inc eased isk o abo ion, oe al loss, p e e m deli e y, low bi h weigh ,
p ema u e up u e o memb anes, p ema u e placen al ab up ion, o delayed oe al g ow h [
3
,
4
].
Despi e ex ensi e in o ma ion being a ailable on he isks o obacco smoking o he oe us du ing
p egnancy, some women con inue o smoke [
5
]. Mos coun ies lack cu en da a on he p e alence
o obacco use du ing p egnancy [
6
]. Es ima es sugges , howe e , ha 1.7% o p egnan women
wo ldwide a e smoke s. In Eu ope, i is es ima ed ha 8.1% o he p egnan popula ion smokes, a
igu e conside ably highe han he global a e age [
6
]. In Spain, he igu es a e e en mo e discou aging,
anging be ween 30–45% o women smoking obacco in ea ly p egnancy [
7
,
8
], al hough a ound 40% o
hose usually qui wi hin he i s imes e o p egnancy [7].
To analyse obacco use du ing p egnancy, di e en me hods ha e been used o measu e obacco
exposu e, including sel -adminis e ed ques ionnai es, measu emen s o expi ed ca bon monoxide o
co inine concen a ion in u ine [9,10].
Heal h li e acy (HL) ela es o he use ’s knowledge and skills in decision-making in a medical
and social con ex [
11
]. These skills include eading, w i ing, making calcula ions, communica ing,
sea ching o in o ma ion, using elec onic echnologies and sol ing p oblems, all o which a e
essen ially pe sonal and social skills o na iga ing he heal h sys em [12,13].
Cu en ly, he e a e di e en s anda dised and alida ed ins umen s a ailable o assessing HL,
mos ly in English [
14
] and ocused on No h Ame ican ci izens. In Eu ope, he e is a collabo a ion
o s anda dise a alid ques ionnai e [
11
] applicable o Eu opean people [
15
]. In Spanish, he e a e
p e iously alida ed and widely ecognised ques ionnai es, such as Sho Assessmen o Heal h
Li e acy o Spanish Adul s (SAHLSA_50) [
16
–
18
], Newes Vi al Sign (NVS) [
19
–
22
] and Single I em
Li e acy Sc eene (SILS) [23].
The e is cu en ly con o e sy ega ding he ou ine use o popula ion sc eening o HL. Some
expe s ecommend conside ing he en i e popula ion as ha ing a low HL le el [
24
], claiming
ha ou ine sc eening o HL has no shown bene i s and could ha e undesi ed e ec s. On he
con a y, di e en p o essional o ganisa ions [
11
,
25
] p omo e HL sc eening o each he la ges possible
popula ion and p o ide unde s andable and accessible in o ma ion, ega dless o he le el o HL.
Mul iple bio-psycho-social and economic ac o s in luence bo h decisions o s a and qui smoking
obacco [
16
,
26
–
28
]. HL is eme ging as a undamen al media o o such decisions [
29
]. Limi ed o poo
HL appea s o be a c ucial ac o in smoking om adolescence [30] o adul s o e 50 yea s [31].
Di e en s udies on possible demog aphic p edic o s ela ed o smoking ha e been published
in e na ionally, al hough he bene i o in e en ions ca ied ou du ing p egnancy is s ill inadequa e [
5
,
32
–
34
]. Li le is known abou he impac o heal h li e acy on women’s heal h and obacco use
in p egnancy.
The e o e, his s udy aimed o analyse he ela ionship be ween he HL o pue pe al women and
obacco consump ion du ing p egnancy.
2. Me hods
2.1. Design, Popula ion, and Sample
A mul icen e, desc ip i e, c oss-sec ional s udy was ca ied ou h ough a su ey in women in
he ea ly pue pe ium (48 h pos pa um), who ga e bi h a he Lluis Alcany
í
s Hospi al (LLAH) and
La Ribe a Uni e si y Hospi al (LRUH), bo h abu ing a he sou he n a ea o Valencia (Spain). These
hospi als se e a popula ion o 250,000 and 210,000 inhabi an s, espec i ely, wi h an annual a e age
o 1800 (LRUH) and 1100 (LLAH) bi hs in he yea he s udy was ca ied ou .
In . J. En i on. Res. Public Heal h 2020,17, 2910 3 o 12
Pos pa um women du ing No embe 2017 and May 2018 we e included. Those women wi h
isual and hea ing disabili ies ha p e en ed hem om comple ing he ques ionnai e, women
wi h neu o-cogni i e pa hology, demen ia o diagnosed men al heal h diso de s, hose e using o
pa icipa e in he s udy, hose wi h a language ba ie ha hinde ed unde s anding, o hose unde 18,
we e excluded.
Assuming a p e alence o 20% obacco use in he adequa e HL g oup, admi ing a li e acy a io o
2:1 (adequa e: inadequa e) wi h 80% s a is ical powe and a ype I e o o 0.05%, o de ec a p e alence
o 40% in he inadequa e HL g oup, 189 pa icipan s we e necessa y o he s udy. To accoun o 5% o
possible a i ion, we es ima ed a sample o 198 pa icipa ing women.
I should be highligh ed ha he only beha iou conside ed by in e iewe s and pa icipan s
was obacco smoking, no da a was ga he ed ega ding ma ijuana o o he obacco- ela ed p oduc s
(e-ciga e es, snus, ciga s, chewing obacco, wa e pipes, e c.)
The s udy was ca ied ou acco ding o he p inciples o he Decla a ion o Helsinki o all medical
esea ch. The s udy was app o ed by he LRUH E hics (HULR20170917) and Resea ch Commi ee on
27/09/17.
2.2. Da a Collec ion
P io o da a collec ion, w i en consen was eques ed om each pa icipan . Sys ema ic sampling
was ca ied ou o he ec ui men p ocess, conduc ing in e iews e e y 7 days wi h women admi ed
o he ma e ni y wa d on each o he days a each hospi al. Da a we e ob ained ollowing wo di e en
me hods: in e iews (sociodemog aphic, obs e ical and le el o HL a iables) and elec onic heal h
eco ds e iew ( a iables ela ed o obacco use).
Du ing he immedia e pue pe ium (24–48 h pos pa um), an in e iew was ca ied ou wi h each
woman o analyse hei le el o HL and collec di e en sociodemog aphic a iables (age, coun y o
o igin, ma i al s a us, occupa ion and ac i i y o he p egnan woman and he pa ne , and educa ion
le el) and obs e ic cha ac e is ics (ges a ional age, pa i y, ype o deli e y and ype o obs e ic isk).
The pa icipan s’ HL was es ima ed using he Newes Vi al Sign (NVS) ool. The ool e alua es
eading comp ehension and nume ical skills based on six ques ions abou he label o he nu i ional
composi ion o an ice-c eam. The sco e is con inuous quan i a i e on 6 possible poin s, co esponding
o inadequa e (0–1 poin s), limi ed (2–3 poin s) and adequa e (4–6 poin s) heal h li e acy. This ool has
been alida ed o he Hispanic popula ion esiding in he Uni ed S a es. I has high sensi i i y, bu i
may misclassi y people wi h adequa e li e acy [
35
]. This ool has also been alida ed o he Spanish
speaking popula ion, wi h mode a e eliabili y (C onbach α=0.69) [22].
Du ing p ena al ollow-up, midwi es in P ima y Ca e in e iewed women ega ding obacco use
in each o he imes e s, and i was egis e ed in hei elec onic heal h eco ds: (1) obacco consumed
du ing p egnancy; (2) he numbe o ciga e es pe day (mean sel - epo ed ciga e es smoked pe day);
(3) in case o qui ing, in which imes e i ook place.
2.3. S a is ical Analysis
A desc ip i e analysis o all a iables was pe o med by calcula ing equencies o quali a i e
a iables, and he minimum, maximum, mean and s anda d de ia ion alues o quan i a i e a iables.
The ac o s associa ed wi h HL measu ed by he NVS sc eening ool we e analysed, as well as
obacco use du ing p egnancy using con ingency ables, applying he Chi-Squa e es o Fishe ’s exac
es o quali a i e a iables, and compa ison o mean alues o he quan i a i e ones, applying he
S uden ’s - es .
Mul i a ia e logis ic models we e adjus ed o es ima e he magni ude o associa ion wi h obacco
consump ion in p egnancy. Odds Ra ios (OR) we e es ima ed along wi h hei 95% CI. A s epwise
a iable selec ion p ocedu e was pe o med based on he AIC (Akaike In o ma ion C i e ium).
Goodness-o - i indica o s and p edic i e indica o s, such as he ROC cu e, a e shown. Analyses
we e pe o med using SPSS .25 (IBM Co p. Released 2017. IBM SPSS S a is ics o Windows, Ve sion
In . J. En i on. Res. Public Heal h 2020,17, 2910 4 o 12
25.0. A monk, NY, USA) and R .3.6.0 so wa e (R Co e Team (2019). R Founda ion o S a is ical
Compu ing, Vienna, Aus ia), o a s a is ical signi icance <0.05.
3. Resul s
Ou o 200 women who we e in o med abou he s udy, 7 women (3.5%) did no wish o o could
no pa icipa e o di e en easons: 4 o hem (57.2%) did no wish o pa icipa e, and 3 (42.8%)
p esen ed a language ba ie . The inal sample included 193 women (96.5%).
The mean age o he women su eyed was 32.9 (SD 5.4), wi h he mean age o he i s p egnancy
being 29.5 (SD 5.6) yea s. 53.3% (103) o he women o he sample we e p imipa ous. The mean
ges a ional week a deli e y was 39.2 (SD 1.4). 29.5% (57) o he women smoked while p egnan , wi h
a mean o 7.2 (SD 4.2) ciga e es pe day a he beginning o he p egnancy. Table 1shows he es o
socio-demog aphic, clinical and obs e ic cha ac e is ics o he sample wi h he g ouped a iables.
We obse ed ha he p e alence o smoke s was signi ican ly highe in he ca chmen a ea o La Ribe a
(p=0.003), in single-di o ced-sepa a ed (p=0.003) and in he low educa ion le el g oup (p=0.017),
as well as in limi ed o inadequa e HL g oup (p=0.004).
Table 1. Clinical and sociodemog aphic cha ac e is ics o he sample by smoke s a us (N=193).
Va iable
To al SMOKER
YES NO
n=57 n=136
N%N%N%p-Value
CATCHMENT AREA
Ribe a 145 75.1 51 89.5 94 69.1 0.003 *
Xa i a-On inyen 48 24.9 6 10.5 42 30.9
MARITAL STATUS
Single-di o ced-sepa a ed 74 38.3 31 54.4 43 31.6 0.003 *
Ma ied 119 61.7 26 45.6 93 68.4
EDUCATION LEVEL
No s udies o P ima y Ed. 58 30.1 24 42.1 34 25.0 0.017 *
VET 31 16.1 11 19.3 20 14.7
HNC 49 25.4 15 26.3 34 25.0
Bachelo ’s deg ee 29 15.0 3 5.3 26 19.1
Uni e si y deg ee 26 13.5 4 7.0 22 16.2
OCCUPATION
Sala ied 114 59.1 31 54.4 83 61.0 0.689
Unemployed 48 24.9 16 28.1 32 23.5
O he s (S uden . SE) 31 16.1 10 17.5 21 15.4
SECTOR
Adminis a ion 43 23.0 14 24.6 29 21.3 0.361
Unemployed 62 33.2 23 40.4 39 28.7
Heal hca e 22 11.8 4 7.0 18 13.2
Se ices 21 11.2 4 7.0 17 12.5
O he s (Indus y. Educa ion) 39 20.9 11 19.3 28 20.6
COUNTRY OF ORIGIN
Spain 177 91.7 52 91.2 125 91.9 0.875
O he 16 8.3 5 8.8 11 8.1
PARTNER’S OCCUPATION
En ep eneu 21 10.9 6 10.5 15 11.0 0.943
Sala ied wo ke 157 81.3 46 80.7 111 81.6
O he s 15 7.8 5 8.8 10 7.4
PREGNANCY RISK
In . J. En i on. Res. Public Heal h 2020,17, 2910 5 o 12
Table 1. Con .
Va iable
To al SMOKER
YES NO
n=57 n=136
N%N%N%p-Value
Low isk 154 79.8 42 73.7 112 82.4 0.171
High isk 39 20.2 15 26.3 24 17.6
HEALTH LITERACY
Adequa e 112 58.0 24 42.1 88 64.7 0.004 *
Limi ed o inadequa e 81 42.0 33 57.9 48 35.3
*p<0.05 Chi-Squa e o Fishe ’s exac es s. VET: Voca ional Educa ion and T aining; HNC: Ce i ica e o Highe
Educa ion (HNC); SE: Sel -employed; NVS: Newes Vi al Sign.
The smoking cessa ion a e du ing p egnancy was 70.2% (40). P egnan women who did no
qui du ing p egnancy had a mean obacco use o 8.35 (SD 4.8) ciga e es pe day, compa ed o hose
who qui smoking, wi h 6.7 (SD 3.9) ciga e es pe day. The di e ences ound we e no s a is ically
signi ican be ween he mean obacco consump ion and smoking cessa ion a e (n=57; p=0.267).
Smoking cessa ion a e du ing he i s imes e was 36.8% (21), in he second, 22.8% (13), and in he
hi d, 10.5% (6). 29.8% (17) o he p egnan women did no qui .
Table 2shows he abula o ms o quan i a i e a iables by le el o HL. As o HL, he mean sco e
o he NVS scale was 3.7 (SD 1.6) poin s. These alues we e ca ego ised in o inadequa e HL (9.3%
(18)), limi ed HL (32.6% (63)) and adequa e HL (58.0% (112)). Due o sca ce numbe o cases in he
Inadequa e HL ca ego y, Inadequa e and Limi ed HL we e combined, in o de o calcula e chi-squa e.
Table 2. Quan i a i e a iables as pe le el o HL, ANOVA es .
Va iable NMean SD p-Value
NUMBER CIGARETTES/DAY
Adequa e HL 24 7.0 4.4 0.821
Limi ed o inadequa e HL 33 7.3 4.1
AGE
Adequa e HL 112 33.3 4.9 0.255
Limi ed o inadequa e HL 81 32.3 6.0
PARITY
Adequa e HL 112 1.6 1.0 0.572
Limi ed o inadequa e HL 81 1.7 0.9
AGE FIRST PREGNANCY
Adequa e HL 112 30.0 4.9 0.177
Limi ed o inadequa e HL 81 28.9 6.4
GESTATIONAL AGE
Adequa e HL 112 39.2 1.4 0.800
Limi ed o inadequa e HL 81 39.1 1.4
HL: Heal h li e acy; SD: S anda d de ia ion.
Table 3shows he pe cen age o le el o HL ca ego y o qui e s/no qui e s. O he 24 women
wi h Adequa e HL, 16 (67%) qui . Rega ding hose wi h inadequa e o limi ed HL, a la ge pe cen age
qui (24% o 33% o 72%).
In . J. En i on. Res. Public Heal h 2020,17, 2910 6 o 12
Table 3. Pe cen age o le el o HL o qui e s/no qui e s (n=57).
Va iable
SMOKING CESSATION DURING
GESTATION
Qui s Does No Qui
n=40 n=17
N%N%p-Value
HEALTH LITERACY
Adequa e HL 16 66.7 8 33.3 0.771
Inadequa e o limi ed HL 24 72.7 9 27.3
HL: Heal h Li e acy by Newes Vi al Sign.
The deg ee o heal h li e acy and he es o a iables we e p esen ed in Table 4. The esul s
sugges ha he highe he le el o educa ion, he highe he HL (p<0.001). Sala ied wo ke s had a
highe le el o HL han hose unemployed (p=0.041), jus like women wo king in adminis a ion o in
he heal h sec o , who had a highe HL han hose unemployed o hose wo king in he se ice sec o
(p=0.008). Non-smoke s had a highe HL han smoke s (p=0.004). Women wi h low- isk p egnancies
had a highe HL han hose a high isk (p=0.016).
Table 4.
Rela ionship be ween he deg ee o HL and clinical and sociodemog aphic a iables (N =193).
Va iable
Adequa e HL Inadequa e o
Limi ed HL
n=112 n=81
N%n%p-Value
CATCHMENT AREA
Ribe a 83 57.2 62 42.8 0.828
Xa i a-On inyen 29 60.4 19 39.6
MARITAL STATUS
Single-di o ced-sepa a ed 36 48.6 38 51.4 0.037 *
Ma ied 76 63.9 43 36.1
LEVEL OF EDUCATION
No s udies o P ima y Ed. 20 34.5 38 65.5 <0.001 *
VET 13 41.9 18 58.1
HNC 32 65.3 17 34.7
Bachelo ’s deg ee 24 82.8 5 17.2
Uni e si y deg ee 23 88.5 3 11.5
OCCUPATION
Sala ied 74 64.9 40 35.1 0.041 *
Unemployed 21 43.8 27 56.2
O he s (S uden , SE) 17 54.8 14 45.2
SECTOR
Adminis a ion 30 69.8 13 30.2 0.008 *
Unemployed 26 41.9 36 58.1
Heal hca e 17 77.3 5 22.7
Se ices 11 52.4 10 47.6
O he s (Indus y, Educa ion)
26 66.7 13 33.3
COUNTRY OF ORIGIN
Spain 106 59.9 71 40.1 0.082
O he 6 37.5 10 62.5
PARTNER’S OCCUPATION
En ep eneu 15 71.4 6 28.6 0.305
Sala ied wo ke 90 57.3 67 42.7
In . J. En i on. Res. Public Heal h 2020,17, 2910 7 o 12
Table 4. Con .
Va iable
Adequa e HL Inadequa e o
Limi ed HL
n=112 n=81
N%n%p-Value
O he s 7 46.7 8 53.3
DELIVERY TYPE
Spon aneous 56 55.4 45 44.6 0.201
Ins umen al 30 69.8 13 30.2
C-sec ion 26 53.1 23 46.9
SMOKER
Yes 24 42.1 33 57.9 0.004 *
No 88 64.7 48 35.3
PREGNANCY RISK
Low isk 96 62.3 58 37.7 0.016 *
High isk 16 41.0 23 59.0
*p<0.05 Chi-Squa e o Fishe ’s exac es s. HL: Heal h Li e acy by Newes Vi al Sign; VET: Voca ional Educa ion
and T aining; HNC: Ce i ica e o Highe Educa ion (HNC); SE: Sel -employed.
Finally, a mul i a ia e logis ic model was cons uc ed wi h he a iables ha showed s a is ical
signi icance and clinical ele ance o de e mine he magni ude o associa ion wi h smoking du ing
p egnancy wi h he di e en explana o y a iables (Table 5). Thus, we obse ed ha limi ed and o
inadequa e li e acy was s ongly associa ed wi h obacco use, adjus ed by ca chmen a ea and age o
i s p egnancy, ob aining a model ha i s well he da a well (LRT p<0.001; ROC cu e =0.71, 95% CI:
0.64–0.79).
Table 5. Mul i a ia e logis ic eg ession model o obacco use du ing p egnancy (N=193).
Va iable Va iable OR 95% CI p-Value
HEALTH LITERACY Adequa e 1
Limi ed o
inadequa e 2.39
(1.24–4.63)
0.010 *
AGE FIRST
PREGNANCY 0.94
(0.88–0.99)
0.027 *
CATCHMENT AREA Ribe a 1
Xa i a-On inyen 0.28
(0.11–0.71)
0.008 *
*p<0.05.
4. Discussion
This s udy p esen s he e alua ion o HL in women du ing he pue pe ium in Spain, and acco ding
o hei obacco consump ion. The esul s sugges ha he le el o HL is in e sely associa ed wi h
obacco consump ion, as has been obse ed in o he popula ions [
36
], bu no so much as in p egnan
o pos pa um women.
Mo eo e , a low HL has been ela ed o being unma ied, ha ing a low educa ion le el, being
unemployed, being a smoke , no qui ing obacco du ing ges a ion and ha ing a high- isk p egnancy.
The ela ionship be ween socioeconomic s a us, educa ion le el and o he ac o s, bo h in p egnan
women and in adul s, ha e al eady epo ed obacco use, and hey coincide wi h ou esul s [
5
,
37
–
39
].
Mo eo e , HL does no necessa ily e lec wha would o he wise be conside ed gene al li e acy, gi en
he numbe s o women wi h limi ed educa ional a ainmen showing adequa e HL and he inding
ha some women wi h high educa ional a ainmen showing limi ed o inadequa e HL [11,13].
All hese ac o s could be ela ed o he in e gene a ional ansmission o heal h inequali ies,
as o he s udies ha e al eady ound [40].
In . J. En i on. Res. Public Heal h 2020,17, 2910 8 o 12
The p opo ion o p egnan women who qui smoking du ing he i s imes e and be o e
deli e y coincides wi h p e ious s udies [
7
], al hough no s a is ically signi ican di e ences we e
ound be ween he le el o HL and smoking cessa ion du ing p egnancy. The associa ions a e s ill
signi ican a e adjus ing o sociodemog aphic and clinical cha ac e is ics known o be associa ed
wi h he p e alence o obacco use. The e o e, HL seems o be an associa ed ac o wi h obacco use,
and p egnan women wi h a lowe HL may be mo e likely o con inue o smoke du ing p egnancy.
Smoking du ing p egnancy has been associa ed wi h sociodemog aphic ac o s such as lowe
economic le el, high pa i y, ha ing no pa ne o ha ing a pa ne who smokes, ha ing a lowe
educa ional le el and ha ing a highe consump ion o ciga e es he day be o e p egnancy [
5
].
Addi ionally, he e a e mo i a ional ac o s in ol ed such as no belie ing ha obacco a ec s he
heal h o he oe us o newbo n o ha ing smoked in p e ious p egnancies [
41
]. Mo eo e , de e mining
whe he o no he women’s mo i a ional aspec s we e he main eason o qui ing smoking, o as a
esul o he p ocess, is di icul and was no conside ed in ou s udy.
Few s udies ha e in es iga ed he ela ionship be ween HL and smoking; howe e , a s udy
conduc ed in Louisiana (USA) in 2001 es ima ed he ela ionship be ween HL and smoking isk
knowledge and a i udes among low-income p egnan smoke s [
39
]. The esul s o hese au ho s
indica ed ha a low HL was associa ed wi h lowe knowledge o he isk o smoking and less nega i e
a i udes ela ed o smoking. The p o ile o he woman included in he s udy, om 12 o 43 yea s
o age wi h low economic esou ces, is a om he cha ac e is ics o he women in ou s udy. In a
sys ema ic e iew in 2016, he ela ionship be ween hese a iables was e iden in adolescen s and
young adul s [36].
The esul s obse ed in ou s udy p o ide e idence ha low HL can be an impo an and
independen associa ion ac o wi h obacco use du ing p egnancy, con a y o wha happens in o he
g oups [
42
,
43
]. The esul s also show ha HL is ela ed o sociodemog aphic cha ac e is ics and ha i
can be an impo an elemen o explain he heal h dispa i ies in p egnan women [
14
,
43
–
45
], since we
ha e been able o obse e ha he same de e minan s ha ma k obacco use in luence HL, and ha i
is possible ha HL may be a link be ween hese g oups.
Low HL could also hinde sel -e icacy in complying wi h he he apeu ic ollow-up o he di e en
pha macological app oaches o beha iou al echniques o qui smoking [
46
,
47
], and ha s ess ul
en i onmen s ha a ou obacco consump ion may include ac o s ha d i e low HL. Pe haps
add essing o mi iga ing some o hese common de e minan s could o e a bene i o HL and obacco
use, o e en p ena al planning ha would acili a e smoking o be s opped be o e ges a ion in a planned
manne . This hypo hesis should be ialled in u u e s udies since i is beyond ou main objec i e.
HL plays an impo an ole in in luencing how smoke s espond o di e en isk messages [
48
].
I is c ucial o ailo heal h p omo ion messages o women wi h low HL, as has al eady been p oposed
by o he au ho s [
46
,
49
]. The e o e, ou indings highligh he impo ance o inc easing awa eness
o he impac o HL on subop imal heal h beha iou s, including obacco use du ing p egnancy and
imp o ing he aining o heal hca e wo ke s o communica e clea ly abou he isks o smoking [
43
].
Once we ha e obse ed he associa ion be ween HL and obacco consump ion, we could sugges ha by
p o iding in o ma ion acco ding o he le el o HL, we could make i mo e easible o p egnan women
o qui smoking. Heal hca e p o ide s should be ained o communica e clea ly wi h pa ien s abou
he heal h consequences o smoking, o example, use plain language, isual aids (e.g., pic og aphs),
and echniques such as he each-back me hod o con ey smoking heal h isks [
42
]. Di e en s a egies
ha e been epo ed in he li e a u e, such as he use o simple language, indi idual eaching, di e en
eaching me hods, and elec onic ools, all wi h posi i e esul s. Any speci ic communica ion o
aining in e en ion in low HL g oups would imp o e he indi idual’s unde s anding and sel -ca e,
as di e en andomised clinical ials ha e concluded [50–53].
In . J. En i on. Res. Public Heal h 2020,17, 2910 9 o 12
4.1. Limi a ions
Fi s ly, ou esul s a e based on he alidi y o he esponses o he sel - epo ed ques ionnai e.
We a e awa e ha measu ing obacco use h ough a sel - epo ed ques ionnai e is a limi a ion and ha
i would ha e been be e also o ca y ou u ine co inine o ca bon monoxide es ing. Consequen ly,
he smoking a e obse ed may indeed unde es ima e he ue a io, due o he po en ial o socially
desi able esponses by he pa icipan s. The ac o s mos closely ela ed o concealing one’s smoking
s a us ha e o do wi h he iming, and he quan i y o obacco consumed [
7
]. Some au ho s ha e obse ed
he deeply associa ed s igma wi h smoking in public while p egnan ; he e o e, ou igu es could be
e en mo e conce ning [
31
]. Secondly, he s udy design only allows us o epo on associa ions and no
causal ela ionships. The e o e, u u e s udies should in es iga e possible unde lying bio-psycho-social
mechanisms be ween low HL and obacco consump ion du ing ges a ion and i s cessa ion. In he
hi d place, he measu emen o HL was ca ied ou du ing he ea ly pue pe ium (48 h pos pa um).
We ha e assumed ha HL is demons a ed consis en ly om he beginning o he end o p egnancy
and ha du ing p egnancy, no subs an ial modi ica ion o HL is expec ed. This me hodology has
al eady been used by di e en au ho s [
37
,
46
]. To ou knowledge, no s udies exis e alua ing ini ial
and inal HL le els wi hou in e en ion in p egnan women, so u u e s udies should look in o his.
Finally, he economic s a us was no a ailable as a a iable, bu we measu ed he educa ion le el,
occupa ion and ac i i y, which a e also socioeconomic s a us indica o s in line wi h o he au ho s [
31
].
4.2. S eng hs
P obabilis ic sampling was used o selec he s udy popula ion. Mo eo e , he es ima ed sample
size was eached, mee ing he sample ep esen a i eness c i e ion, and he NVS ool is a ailable
and eely accessible, bo h in Spanish and English. Fo all hese easons, he s udy demons a es
i s ansla ional in e es , since i p ospec i ely iden i ies he popula ion o which we can adap he
in o ma ion o achie e smoking cessa ion.
5. Conclusions
A low HL is associa ed wi h obacco consump ion du ing p egnancy. Whe he low HL e lec s he
wide cons ella ion o al eady known socioeconomic, poli ical and comme cial de e minan s o obacco
use, o whe he inco po a ing HL suppo in e en ions s eng hens obacco cessa ion ac i i ies in
p egnancy, wa an s u he esea ch. S ill, i should be conside ed as essen ial o unde s anding he
heal h dispa i ies ela ed o i s consump ion.
Au ho Con ibu ions:
R.V.-C. Designed he p o ocol and led he p ojec ; R.V.-C. and F.J.S.-V. Collec ed he
necessa y da a; J.A.Q. and P.P.-R. pe o med he s a is ical analysis. R.V.-C., D.M.-T., E.N.-I., F.J.S.-V., E.C.-S. and
P.P.-R. w o e he i s d a , wi h all au ho s p o iding c i ical commen s. E.N.-I., R.V.-C. unding acquisi ion.
All au ho s con ibu ed o he in e p e a ion o esul s. All au ho s ha e ead and ag eed o he published e sion
o he manusc ip .
Funding:
Ou esea ch g oup has ecei ed unding h ough a compe i i e call om he Ca holic Uni e si y o
Valencia “San Vicen e Má i ” (UCV) o ca y ou his s udy (UCVPRO.18-19.AII.10).
Acknowledgmen s:
The au ho s wish o hank he Ca holic Uni e si y o Valencia “San Vicen e M
á
i ” and La
Ribe a Uni e si y Hospi al o hei suppo and pa icipa ion in he p ojec and all s udy pa icipan s. ECS is
a ilia ed wi h he Na ional Ins i u e o Heal h Resea ch Heal h P o ec ion Resea ch Uni (NIHR HPRU) [g an
numbe HPRU-2012-10047] in Heal hca e Associa ed In ec ions and An imic obial Resis ance a Impe ial College
London in pa ne ship wi h Public Heal h England (PHE), he is an NIHR Senio Nu se and Midwi e Resea ch
Leade , and acknowledges he suppo o he NIHR Biomedical Resea ch Cen e. The iews exp essed a e hose o
he au ho (s) and no necessa ily hose o he NHS, he NIHR, he Depa men o Heal h o Public Heal h England.
Con lic s o In e es : The au ho s decla e no con lic o in e es .
