Influence of neighbourhood purchasing power on breastfeeding at four months of age: a Swedish population-based cohort study.
BACKGROUND
Parental socioeconomic status (SES) is an important determinant in child health, influencing beneficial factors such as breastfeeding. A better understanding of the influence of neighbourhood-level SES measures, relating to spatial determinants, might lead to targeted actions to promote breastfeeding during infancy.


METHODS
A cross-sectional study analysis the association between breastfeeding at four months of age and neighbourhood purchasing power, taking account of individual-level variables including maternal age, smoking and parental level of education. Data were obtained from a prospective population- based cohort study recruited from birth in 2007-2008 in the Halland region, southwestern Sweden. Questionnaire data on the individual-level variables and the outcome variable of breastfeeding at four months (yes/no) were used (n=2,407). Each mother was geo-coded with respect to her residential parish (there are 61 parishes in the region) and then stratified by parish-level household purchasing power. It emerged that four neighbourhood characteristics were reasonable to use, viz. <10%, 10-19%, 20-29% and ≥ 30% of the resident families with low purchasing power.


RESULTS
The proportion of mothers not breastfeeding at four months of age showed a highly significant trend across the neighbourhood strata (p=0.00004): from 16.3% (< 10% with low purchasing power) to 29.4% (≥ 30% with low purchasing power), yielding an OR of 2.24 (95% confidence interval: 1.45-3.16). After adjusting for the individual-level variables, the corresponding OR=1.63 (1.07-2.56) was significant and the trend across the strata was still evident (p=0.05). A multi-level analysis estimated that, in the neighbourhoods with ≥ 30% of the families with low purchasing power, 20% more mothers than expected, taking account of the individual-level factors, reported no breastfeeding at four months of age (≥ 95% posterior probability of an elevated observed-to-expected ratio).


CONCLUSIONS
The neighbourhood purchasing power provided a spatial determinant of low numbers of mothers breastfeeding at four months of age, which could be relevant to consider for targeted actions. The elevated observed-to-expected ratio in the neighbourhoods with the lowest purchasing power points toward a possible contextual influence.
Child Health Care Unit, Region Halland SE-434 80, Kungsbacka, Sweden. Gerd.almquist-tangen@regionhalland.se.
Gerd
G
Almquist-Tangen
Ulf
U
Strömberg
Anders
A
Holmén
Bernt
B
Alm
Josefine
J
Roswall
Stefan
S
Bergman
Jovanna
J
Dahlgren
D000293:Adolescent; D000328:Adult; D001942:Breast Feeding / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D007223:Infant; D008423:Maternal Age; D008875:Middle Aged; D009035:Mothers / Q000706:statistics & numerical data*; D055361:Multilevel Analysis; D011446:Prospective Studies; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012907:Smoking; D012923:Social Class; D013548:Sweden; D055815:Young Adult