Table 2.
Characteristics of studies included in the systematic review
| Author/publishing year | Country/year of study | Study design | Quality score | Sample size | Outcome (age group) | Exposure (age group) | Prevalence of EBF interruption € | Prevalence of pacifier use € | Effect size | Factors at baseline to match intervention and control groups | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Jenik, 2009 | Argentina 2005–2006 | Randomized Clinical Trial | Strong | 1021 | EBF interruption at 4 months | Pacifier use at 4 months | 25.3% | 51.4% | OR* 1.04
(0.78–1.40) |
Birth weight(c); type of delivery(b); maternal age(a); maternal education(a); mother smoker(a); marital status (cohabiting with the father)(a); birth in BFH(e); early initiation of breastfeeding(e) | ||
| Kramer et al., 2001 | Canada 1998–1999 | Randomized Clinical Trial | Strong | 281 | EBF interruption at 3 months | Pacifier use at 3 months | 65.1% | 50.7% | RR 1.0
(0.8–1.1) OR* 1.12 (0.67–1.87) |
Mean maternal age(a); Mean maternal education(a); Mother smoking during pregnancy(a); maternal work status(a); marital status(a); Parity(a); prior experience maternal on breastfeeding(d); mean baby birth weight(c) | ||
| Effect size | Factors associated with outcome | |||||||||||
| Crude | Adjusted | Significance | Non‐ significance | |||||||||
| Lindau et al., 2014 | Italy
2000–2001 |
Longitudinal | Moderate | 542 | EBF interruption at 4 months | Pacifier use before second week | 83.9% | 64.4% | OR 2.39
(1.38–4.14) |
OR 2.38
(1.35–4.20) |
Maternal emotional distress(a); type of delivery(b); attending prenatal classes(b) | Mother's age(a); mother's education(a); maternal smoking habits(a) |
| Vieira, Vieira, Oliveira, Mendes, & Giugliani, 2014, ** | Brazil
2004–2005 |
Longitudinal | Strong | 1344 | EBF interruption in the first 6 months | Pacifier use in each month | 88.7% | 44.8% | N/R | HR 1.40
(1.14–1.71) |
Mother's education(a); Maternal work status(a); number of prenatal visits(b); prenatal care in public service(b); birth in BFHI(e); breastfeeding counseling at the hospital(e); mother's partner support breastfeeding(d); limit the number of feedings at night(d); cracked nipples(d) | Ethnic group(a); mother's age(a); parity(a); previous experience with breastfeeding(d); marital status(a); normal birth; breastfeeding within 1 hour(e); baby's sex(c). |
| Carrascoza et al., 2011 | Brazil
2004 |
Longitudinal | Strong | 111 | EBF interruption at 6 months | Pacifier use in the follow‐up | 48.6% | 20.7% | N/R | OR 11.46
(3.09–42.37) |
Social class(a); maternal work status(a) | ‐ |
| Vieira, Martins, Vieira, Oliveira, & Silva, 2010 | Brazil
2004 |
Longitudinal | Weak | 1309 | EBF interruption at the end of the first month | Pacifier use at the end of the first month | 40.7% | 41.5% | OR 1.58
(1.39–1.80) |
OR 1.53
(1.34–1.76) |
Prior maternal experience with breastfeeding(d); pre‐established schedules for breastfeeding(d); cracked nipples(d) | ‐ |
| Barros et al., 2009 | Brazil
2006 |
Longitudinal | Moderate | 104 | EBF interruption at 6 months | Pacifier use in the follow‐up | 91.7% | third month:
54% |
RR 0.9
(0.6–1.2) OR* 0.59 (0.12–3.07) |
N/R | ‐ | ‐ |
| Kronborg & Vaeth, 2009, ** | Denmark
2004 |
Longitudinal | Strong | 780 | EBF interruption between 1st and 26th week | Pacifier use during the first second week | N/R | 64.3% | HR 1.42
(1.19–1.69) |
HR 1.42
(1.18–1.72) |
Early breastfeeding problems(d) | Maternal education(a); prior maternal experience with breastfeeding(d); use of formula 5 days of life(d); effective breastfeeding technique (d) |
| Espirito‐Santo et al., 2007, ** | Brazil
2003 |
Longitudinal | Strong | 220 | EBF interruption in the first 6 months | Pacifier use during the first month | 93.4% | 63% | HR 1.70
(1.27–2.29) |
HR 1.53
(1.12–2.11) |
Mother's age(a); number of prenatal visits(b); incorrect breastfeeding technique (latch) in the first month(d) | Breastfeeding duration of the previous child(d); parity(a); mother cohabiting with her husband(a), with maternal grandmother(a), with paternal grandmother(a); breastfeeding difficulty (positioning) in the 1st month(AM |
| Chaves et al., 2007, # | Brazil
2003 |
Longitudinal | Strong | 246 | EBF interruption at 6 months | Pacifier use in the follow‐up | 94.7% | N/R | N/R | RR 1.49
(1.11–2.00) |
Prior maternal intention to breastfeed(d); birth weight(c) | Maternal incorrect answer about breastfeeding technique(d); mother being user of alcohol or tobacco(a) |
| Xu et al., 2007, ** | China
2003–2004 |
Longitudinal | Strong | 1219 | EBF interruption at 6 months | Pacifier use at second week | 97% | 60.2% | N/R | HR 1.57
(1.19–2.08) |
Maternal work status(a); maternal grandmother have not breastfeeding their children(d); length decision time of feeding method (d) | Mother's age(a); maternal work status(a); maternal education(a); parity(a); type of delivery(b); first feed of the baby(e); baby's behavior to feed(c); initiate breastfeeding within 30 min of birth (e); baby needed special care unit(c); prenatal care(b); grandmother or father do not support breastfeeding in two weeks(d); feeding preference of the grandmother(d); baby's sex(c); family income(a). |
| Mascarenhas, Albernaz, Silva, & Silveira, 2006 | Brazil
2002–2003 |
Longitudinal | Strong | 973 | EBF interruption before 3 months | Pacifier use at 3 months | 61% | 64% | OR 4.25
(3.19–4.27) |
OR 4.27
(3.19–5.72) |
Maternal work status(a); family income(a); father's education(a) | Materlnal education(a); maternal smoking habits during pregnancy(a); number of prenatal visits(b) |
| Cotrim, 2005 | Brazil
2004 |
Longitudinal | Moderate | 89 | EBF interruption at 4 months | Pacifier use at the first week | 100% | 50.6% | OR* 2.53
(1.39–4.60) |
RR 3.75
(1.91–7.34) |
Breastfeeding during the night(d); had a child under 5 years(a) | ‐ |
| Merten et al., 2005 | Switzerland
2003 |
Longitudinal | Moderate | 1547 | EBF interruption in the first 6 months | Pacifier use in the first week | 62.7% | 76.8% | OR* 1.86
(1.46–2.36) |
HR 1.38
(1.25–1.52) |
Rooming in(d); breastfeeding within first hour(e); breastfeeding on schedule(e); free use of formula supplements(e). | Medical problems before, during, and after delivery(e); type of delivery(b); maternal smoking(a); maternal age(a); ethnic group(a); region of residence(a); maternal education(a); work status(a)and income(a) |
| Nelson, 2005 | Multicentric
(17 countries) 1995–1997 |
Longitudinal | Moderate | 5142 | EBF interruption at 10–14th week | Pacifier use most of the time between 10–14th week | 57%
(20–96%) |
49%
(12–71%) |
OR 1.95
(1.07–3.56) |
OR 1.85
(1.01–3.38) |
Mother intends to breastfeed after birth(d); multiple pregnancy(b); maternal age(a); pacifier use at some moment(d) | Maternal smoke(a); bed shared at the moment of household questionnaire(d); maternal education(a) |
| Butler, Williams, Tukuitonga, & Paterson, 2004 | New Zealand
2000 |
Longitudinal | Moderate | 1398 | EBF interruption in sixth week | Pacifier use at sixth week | 38% | 23.8% | OR 2.58
(1.92–3.46) |
OR 2.48
(1.79–3.44) |
Maternal work status(a); mother was working at 6 weeks(a); child attend daycare(a); parity(a); maternal smoking habits(a); to receive medical visit at home(e); to receive visiting nurse(e); baby sleep separated from their parents(d); hospital discharge of the mother and baby at different times(e). | ‐ |
| Giovannini et al., 2004, ** | Italy
1999–2000 |
Longitudinal | Strong | 2450 | EBF interruption at 6 months | Pacifier use at first month | 95.3% | N/R | N/R | HRadj 1.28
(1.13–1.45) |
Mother's body mass index(a); Infant's body weight at age 1 mo.(c); early introduction of solid foods(d) | Mother's age(a); education level(a); social class(a); maternal smoking habits(a); type of delivery(b); mothers having been breastfed themselves(d); infant's gender(c); bodyweight and length at birth(c); pacifier use at hospital discharge(e); parity(a); time at introduction of formula or solid foods(d); formula promotion at discharge(e); time at initiation of breastfeeding(e). |
| Santiago, Bettiol, Barbieri, Guttierrez, & Del Ciampo, 2003 | Brazil
2002 |
Longitudinal | Moderate | 101 | EBF interruption at 4 months | Pacifier use at 4 months | 39.6% | 40.6% |
EBF interruption:
OR* 4.69 (1.99–11.05) |
EBF duration: OR 0.23
(0.08–0.60) |
Maternal education(a); Follow‐up with medical or team expert in breastfeeding(e) | Parity(a); use of oral contraceptive(a); planned pregnancy(b); birth weight(c); weight gain in the months of follow‐up(c); child sleeps more than 6 hr(d) |
| Ingram et al., 2002, *** | England
1996–1998 |
Longitudinal | Moderate | 1400 | EBF interruption at second week
EBF interruption at sixth week |
Pacifier use at the second week
Pacifier use at the sixth week |
N/R | N/R | N/R | 2ª week:
ORadj 3.07 6ª week: OR adj 4.52 |
6th week:
Mother have plenty of milk supply(d); not provide other liquid to the child in the hospital(e); have sufficient support in the hospital(e); maternal age(a); breastfeeding problems(d); family support(d); health professionals advice and support(e) |
6th week:
child's sex(c); birth weight(c); gestational age(c); parity(a); type of delivery(b); to receive conflicting advice from health professionals(e); mother has enough help at home(d); days in hospital(e) |
| Aarts et al., 1999 | Sweden 1989–1992 | Longitudinal | Moderate | 506 | EBF interruption at 4 months | Pacifier use at the first month | 60% | 15.4% | OR*1.82
(1.20–2.76) |
N/R | ‐ | ‐ |
| Riva et al., 1999 | Italy
1995 |
Longitudinal | Moderate | 1365 | EBF interruption at 6 months | Pacifier use at the first month | 91.9% | 73.0% | RR 1.42
(1.24–1.62) |
RRadj 1.35
(1.18–1.55) OR$ 1.35 (1.18–1.55) |
Maternal education(a); supplemental use in the hospital(e) | Maternal age(a); mother's BMI(a) |
| Barros et al., 1995 | Brazil
1993 |
Longitudinal | Moderate | 605 | EBF interruption at 4 months | Pacifier use at the first month | 66.7% | 54.8% | OR* 4.53
(3.12–6.58) |
N/R | ‐ | ‐ |
| Alves, Oliveira, & Moraes, 2013 | Brazil
2003–2006 |
Cross‐sectional | Strong | 2003: 589
2006: 707 |
EBF interruption among child under 6 months | Pacifier use in the last 24 hr | 2003: 30.2%
2006: 46.7% |
2003: 50.9%
2006: 43.6% |
EBF interruption:
OR* 3.12 (2.48–3.93) |
EBF duration:
RPadj 0.59 (0.50–0.70) |
Maternal education(a); type of delivery(b); infant's age(c); infant follow‐up in a breastfeeding baby‐friendly unit care(e) | Maternal work status(a); birth in BFH(e); sex of the child(c); birth weight(c); immunization center(e). |
| Demitto, Bercini, & Rossi, 2013 | Brazil
2010–2011 |
Cross‐sectional | Weak | 362 | EBF interruption before 6 months | Pacifier use (yes/no) | N/R | N/R | OR 3.2
(1.94–5.24) |
N/R | ‐ | ‐ |
| Siti, 2013 | Malaysia
2006 |
Cross‐sectional | Weak | 2167 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | N/R | 33.6% | OR 9.02
(3.35–25.27) |
ORadj 8.3
(3.02–22.97) |
Area of residence(a) | Sex of the child(c); race(a) |
| Warkentin et al., 2013 | Brazil
2006 |
Cross‐sectional | Weak | 1704 | EBF interruption before 6 months | Pacifier use (yes/no) | N/R | 39% | HR 1.14
OR* 2.33 (1.76–3.09) |
HRadj 1.53
(1.37–1.71) |
Area of residence(a); social class (a); maternal age (a) | Number of prenatal visits(b); Gestation planned(b); maternal education(a); skin‐to‐skin(e); sex of child(c); breast‐feeding within 1 hour(e) |
| Campagnolo, Louzada, Silveira, & Vitolo, 2012 | Brazil
2008 |
Cross‐sectional | Weak | 573 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 0–4 month: 52.9%
4–6 month: 78.6% |
N/R | OR 3.05
(2.11–4.41) |
ORadj 2.85
(1.94–4.18) |
Maternal work status(a); Parity(a) | ‐ |
| Leone, 2012 | Brazil
2008 |
Cross‐sectional | Moderate | 724 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 60.9% | 47.2% | N/R | ORadj 3.02
(2.10–4.36) |
Baby age(c); weight birth(c); maternal work(a) | ‐ |
| Queluz, Pereira, Santos, Leite, & Ricco, 2012 | Brazil
2009 |
Cross‐sectional | Moderate | 275 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 70.2% | 51.6% | OR 1.50
(0.89–2.52) |
ORadj 1.06
(0.61–1.86) |
Maternal work status(a) | Maternal age(a) |
| Salustiano, Diniz, Abdallah, & Pinto, 2012 | Brazil
2008 |
Cross‐sectional | Weak | 667 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 60.3% | 34.3% | OR 4.2
(2.8–6.3) |
N/R | ‐ | ‐ |
| Souza, Migoto, Rossetto, & Mello, 2012 | Brazil
2008 |
Cross‐sectional | Weak | 325 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 66.2% | 50.5% | OR 1.94
(1.15–3.28) |
N/R | ‐ | ‐ |
| Warkentin et al., 2012 | Brazil
2007–2010 |
Cross‐sectional | Weak | 636 | EBF interruption before 6 months | Pacifier use before 3 months | N/R | 79.8% | OR* 1.66
(1.09–2.52) |
HR 1.87
(1.57–2.24) |
Prematurity(c); maternal age(a) | |
| Bouanene, ElMhamdi, Sriha, Bouslah, & Soltani, 2010 | Tunisia
2008 |
Cross‐sectional | Weak | 354 | EBF interruption at 3 months | Pacifier use before 3 months | 84.7% | 78.9% |
EBF duration:
OR 0.17 0.08–0.36 EBF interruption: OR* 4.07 (1.58–10.50) |
N/R | ‐ | ‐ |
| Nascimento et al., 2010 | Brazil
2005 |
Cross‐sectional | Weak | 839 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 56.3% | 49.8% | OR* 2.18
(1.67–2.84) |
RP 1.69
(1.37–2.09) |
Infant's age(c); Maternal education(a). | Maternal work status(a) |
| Parizoto, Parada, Venancio, & Carvalhaes, 2009 | Brazil
1999–2003‐2006 |
Cross‐sectional | Strong | 1999: 496
2003: 674 2006: 509 |
EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months)) | 1999: 91.5%; 2003: 82.4%; 2006: 75.8% | 1999: 65.8%
2003: 57.7% 2006: 54.0% |
OR* 2.44
(1.61–3.71) |
RP 2.03
(1.44–2.84) |
‐ | Maternal education(a); parity(a); type of delivery(b). |
| Kacho, Yadollah, & Pooya, 2007 | Iran
2003–2004 |
Cross‐sectional | Weak | 220 | EBF interruption at 6 months | Pacifier use (yes/no) | 51.4% | 45.5% | OR* 4.18
(2.37–7.37) |
N/R | ‐ | ‐ |
| Franca, Brunken, Silva, Escuder, & Venancio, 2007 | Brazil
2004 |
Cross‐sectional | Weak | 275 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 65.5% | 43.3% | OR 3.27
(1.08–3.24) |
OR 3.26
(1.64–6.50) |
Mother's age(a); parity(a); Maternal education(a) | ‐ |
| Carvalhaes et al., 2007 | Brazil
2004 |
Cross‐sectional | Moderate | 380 | EBF interruption among child under 4 months | Pacifier use in the last 24 hr (under 4 months) | 62.0% | 53.9% | OR 2.69
(1.76–4.11) |
OR 2.63
(1.70–4.06) |
Maternal difficulty or complaint on breastfeeding(d) | Maternal work status(a); parity(a); maternal age(a). |
| Mikiel‐Kostyra 2005a | Poland
1995 |
Cross‐sectional | Weak | 11422 | EBF interruption at hospital discharge | Pacifier use while in hospital | 31.1% | 2.8% | OR 4.97
(3.83–6.45) |
N/R | ‐ | ‐ |
| Mikiel‐Kostyra 2005b | Poland
1997 |
Cross‐sectional | Weak | 10156 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | sixth month
91.0% |
51.0% | OR 2.49
(2.28–2.71) |
OR 2.38
(2.17–2.61) |
Maternal education(a); maternal occupation(a); Mother smoking habits(a); maternal age(a); parity(a); maternal opinion about optimal duration of BF and EBF(d); father's education(a); father's occupation(a). | Maternal marital status(a); father's age(a); working sector of the mother and father(a); father being a smoker(a); sex of the child(c); birth weight(c). |
| Franco, Nascimento, Reis, Issler, & Grisi, 2008 | Brazil
2005 |
Cross‐sectional | Weak | 514 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 56.4% | 49.3% | OR* 4.04
(2.73–5.97) |
N/R | ‐ | ‐ |
| Vieira, Almeida, Silva, Cabral, & Netto, 2004 | Brazil
2001 |
Cross‐sectional | Weak | 1216 | EBF interruption at 6 months | Pacifier use in the last 24 hr (under 6 months | 61.5% | 59.2% | RP 1.60
(1.39–1.84) OR* 2.18 (1.72–2.76) |
N/R | ‐ | ‐ |
| Audi, Correa, & Latorre, 2003 | Brazil
1999 |
Cross‐sectional | Weak | 346 | EBF interruption among child under 6 months | Pacifier use in the last 24 hr (under 6 months) | 4‐6 months 90.4% | 43.4% | OR 4.19
(2.38–7.41) |
OR 4.41
(2.57–7.59) |
Type of delivery(b) | ‐ |
| Cotrim, Venancio, & Escuder, 2002 | Brazil
1999 |
Cross‐sectional | Weak | 22188 | EBF interruption in under 4 months | Pacifier use in the last 24 hr (under 4 months) | 80.8% | 61.3% | OR 3.26
(3.00–3.50) |
N/R | ‐ | ‐ |
| Kelmanson, 1999 | Russia
1998 |
Cross‐sectional | Weak | 192 | EBF interruption between 2 and 4 months | Pacifier use between 2 and 4 months | 50.5% | 60.9% | OR* 1.81
(1.00–3.26) |
N/R | ‐ | ‐ |
| Ford et al., 1994 | New Zealand | Cross‐sectional | Weak | 1592 | EBF interruption at fourth week | Frequent pacifier use in the last two weeks | 39.0% | 18.3% | OR 2.00
(1.39–2.40) |
OR 1.96
(1.35–2.84) |
Multiple pregnancy(b); infant needed hospitalization in the NICU(c); Maternal marital status(a); Occasional use of pacifiers in the last two weeks(d) | Maternal work status(a); sex of the child(c); maternal race (a); Maternal age(a); parity(a); gestational age when mother started prenatal care(b); Pre‐natal care(b); bed sharing(d); infant birth weight(c); Maternal smoke habits(a) |
€
Prevalence provided by publication or calculated from data provided in the paper. The prevalence corresponded to the age group as defined in the outcome and intervention.
§
OR adjusted calculated from data provided by the study.
*
OR unadjusted calculated from data provided by the study.
**
Not included in the meta‐analysis because it was not possible to calculate the OR with the data available.
***
Not included in the meta‐analysis because it was not possible to calculate the IC with the data available.
#
Relative Risk (RR) was considered in the meta‐analysis as a proxy of OR
N/R – Not reported
a,b – Mikael‐Kostyra et al (2005) published the results from two surveys in the same paper, so the results are presented by survey (a) 1995 and (b)1997
Category variable group:(a) Mother and family characteristics; (b) Pregnancy and childbirth factors; (c) Infant characteristics; (d) Breastfeeding technique and family support; (e) Breastfeeding assistance