Table 1: Observational studies on bed share and breastfeeding.

S. no.Study ID/site or countryDesign, settingStudy populationNumber of subjectsIntervention/exposureOutcome (effect size)Comments

1Flick et al. 2001/USA [11]Cross-sectional study (within an interventional study), population basedPregnant women enrolled at 28 wk, contacted at around 8 weeks after deliveryQuestionnaire based survey of 218 consecutive infantsBed shareBreast feeding rate = 61/133 (bed share),
30/85 (no bed share)
OR (95% CI): 1.55 (0.86, 2.84)
Any breast feeding (not exclusive breast feeding) at 8 weeks of age. Loss to followup was 2.2%.

2Ball 2003/United Kingdom [12]Case-control study, population basedHealth infants and mothers, delivered at 36+ weeks. Followed uptill 4 months of ageCases, 112
Controls, 141
Bed shareBreast feeding rate = 81/112 (case),
54/141 (control)
OR (95% CI): 4.2 (2.38, 7.47)
Any breast feeding (not exclusive breast feeding) for ≥1 mo is the definition of the case. Loss to followup was 40%.

3 Blair and Ball 2004/United Kingdom [13]Data from two studies: one was cross-sectional and the other was longitudinal, population based Healthy infants and their mothers at home Data available on 424 subjects Bed shareBreast feeding rate at 4 weeks = 73/84 (bed share), 113/227 (no bed share)
OR (95% CI): 6.66 (3.37, 13.3)
Reported any breast feeding (not exclusive breast feeding rate). Loss to followup was <20%
Breast feeding rate at 3 months = 58/74 (bed share), 202/350 (no bed share)
OR (95% CI): 2.66 (1.43, 5.14)

4 McCoy et al. 2004/USA [14] Cross-sectional study, community based (followup at home of institutional births) Data from the Infant Care Practices Study (ICPS) between years 1995 and 1998. Followup of infants born at selected study hospitals Data available on 10355 subjects Bed shareBreast feeding rate at 1 month = 1346/2071 (bed share), 4142/8284 (no bed share)
Adjusted OR (95% CI): 3.0 (2.6, 3.5)
Reported any BF rate for >4 weeks. Loss to followup was ~30%
Breast feeding rate at 3 months = 725/1346 (bed share), 3107/9009 (no bed share)
Adjusted OR (95% CI): 3.4 (2.9, 4.0)
Breast feeding rate at 6 months = 518/1243 (bed share), 2071/9112 (no bed share)
Adjusted OR (95% CI): 3.6 (3, 4.2)

5Lahr et al. 2007/USA [15]Cross-sectional study (random sample survey), population based Stratified sample of women drawn each month from recently filed birth certificates between years 1998 and 1999 Data available on 1685 subjectsBed shareBreast feeding rate = 485/584 (bed share),
770/1101 (no bed share)
Adjusted OR (95% CI): 2.65 (1.72 to 4.08)
Any breastfeeding for >4 weeks

6 Blair et al. 2010/United Kingdom [16] Prospective longitudinal study, population basedInfants of all pregnant women residing in the 3 health districts of Avon; age group: birth to 4 years. Bed share was categorized into the following 3 groups: early, late, and constant Data available on 7447 subjects Bed shareBreast feeding rate at 6 months = 733/1415 (constant and early bed share), 2111/6032 (no bed share)
OR (95% CI): 2.0 (1.77 to 2.25)
Reported only breast feeding rate (not exclusive breast feeding rate). The adjusted OR for bedsharing in the neonatal age group is not known. Loss to followup was 50% loss.
Breast feeding rate at 12 months = 322/1415 (constant and early bed share), 549/6032 (no bed share)
OR (95% CI): 2.94 (2.52 to 3.44)

7Tan 2011/Malaysia [17]Cross-sectional study, facility basedMother-infant pairs with infants up to 6 months attending health clinics over 4 months in year 2006Data available on 682 subjectsBed share Breast feeding rate = 249/501 (bed share),
45/181 (no bed share)
Adjusted OR (95% CI): 1.50 (1.12 to 2.37)
Exclusive breast feeding rate one month prior to interview. Only 20.3% of study infants were <1 mo of age—data for this subgroup is not known. Loss to followup was <5%

8M llborg et al. 2011/Sweden [18]Cross-sectional study, population basedRandomly selected families with infants who had reached 6 months of ageQuestionnaire based survey on 8176 families Bed shareBreast feeding rate = 544/2035 (bed share),
159/2167 (no bed share)
Adjusted OR (95% CI): 1.94 (1.56 to 2.41)
Any breast feeding (not exclusive breast feeding) at 6 months of age. Loss to followup was 31.5%