A multilevel analysis of the social determinants associated with symptoms of acute respiratory infection among preschool age children in Pakistan: A population-based survey

BACKGROUND

As advocated by WHO in "Closing the Health Gap in a Generation", dramatic differences in child health are closely linked to degrees of social disadvantage, both within and between communities. Nevertheless, research has not examined whether child health inequalities include, but are not confined to, worse acute respiratory infection (ARI) symptoms among the socioeconomic disadvantaged in Pakistan. In addition to such disadvantages as the child's gender, maternal education, and household poverty, the present study also examined the linkages between the community environment and ARI symptoms among Pakistan children under five. Furthermore, we have assessed gender contingencies related to the aforementioned associations.

METHODS

Using data from the nationally representative 2017-2018 Pakistan Demographic and Health Survey, a total of 11,908 surviving preschool age children (0-59 months old) living in 561 communities were analyzed. We employed two-level multilevel logistic regressions to model the relationship between ARI symptoms and individual-level and community-level social factors.

RESULTS

The social factors at individual and community levels were found to be significantly associated with an increased risk of the child suffering from ARI symptoms. A particularly higher risk was observed among girls who resided in urban areas (AOR = 1.42; p<0.01) and who had a birth order of three or greater.

DISCUSSIONS

Our results underscore the need for socioeconomic interventions in Pakistan that are targeted at densely populated households and communities within urban areas, with a particular emphasis on out-migration, in order to improve unequal economic underdevelopment. This could be done by targeting improvements in socio-economic structures, including maternal education.

Household air pollution, ultrasound measurement, fetal biometric parameters and intrauterine growth restriction

BACKGROUND

Low birthweight, intrauterine growth restriction (IUGR) and perinatal mortality have been associated with air pollution. However, intervention studies that use ultrasound measurements to assess the effects of household air pollution (HAP) on fetal biometric parameters (FBP) are rare. We investigated the effect of a cookstove intervention on FBP and IUGR in a randomized controlled trial (RCT) cohort of HAP-exposed pregnant Nigerian women.

METHODS

We recruited 324 women early in the second trimester of pregnancy. Between 16 and 18 weeks, we randomized them to either continue cooking with firewood/kerosene (control group) or receive a CleanCook stove and ethanol fuel (intervention group). We measured fetal biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC) and ultrasound-estimated fetal weight (U-EFW) in the second and third trimesters. The women were clinically followed up at six regular time points during their pregnancies. Once during the women's second trimester and once during the third, we made 72-h continuous measurements of their personal exposures to particulate matter having aerodynamic diameter < 2.5 μm (PM_2.5). We adopted a modified intent-to-treat approach for the analysis. Differences between the intervention and control groups on impact of HAP on fetal growth trajectories were analyzed using mixed effects regression models.

RESULTS

There were no significant differences in fetal growth trajectories between the intervention and control groups.

CONCLUSIONS

Larger studies in a setting of low ambient air pollution are required to further investigate the effect of transitioning to a cleaner fuel such as ethanol on intrauterine growth.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02394574 ; September 2012.

Impact of prenatal and postnatal household air pollution exposure on lung function of 2-year old Nigerian children by oscillometry

RATIONALE

Lung function is adversely affected by exposure to household air pollution (HAP). Studies investigating the impact of prenatal and postnatal HAP exposure on early childhood lung development are limited, especially from Sub-Saharan Africa.

OBJECTIVE

We used oscillometry to investigate the impact on lung function of prenatal and postnatal HAP exposure of children born to Nigerian women who participated in a randomized controlled cookstove intervention trial.

METHODS

We performed oscillometric measurements (R: airway resistance; X: airway reactance; Fres: resonant frequency; AX: reactance area) in 223 children starting at age of 2 years (ethanol stove, n = 113; firewood/kerosene, n = 110). Personal exposure monitoring assessed mothers' prenatal exposure to particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5). Postnatal HAP exposure was measured by determining household PM_2.5 levels. We employed linear regression analysis to examine the association of prenatal and postnatal HAP exposures with children's lung function. Models were adjusted for age, gender, weight, height, group (intervention or control), birthweight and gestational age.

RESULTS

Mean age of the children was 2.9 years (standard deviation = 0.3); 120 were boys (53.8%) and 103 were girls (46.2%). Higher postnatal PM_2.5 exposures were significantly associated with higher airway reactance at 5 Hz (X5 Hz; p = 0.04) in adjusted models. There were no significant associations between prenatal or postnatal PM_2.5 exposure levels and other oscillometry parameters in adjusted regression analysis.

CONCLUSIONS

This is the first study to use oscillometry to explore the relationship between HAP exposure and lung function in children as young as 2 years. The findings provide some evidence that increased postnatal HAP exposure may result in poorer lung function in children, although larger studies are needed to confirm observed results. This study indicates that oscillometry is a low-cost and effective method to determine lung function in early childhood.

A global analysis of the regional variation in the symptoms of acute respiratory infection during childhood: Epidemics and their association with environmental vulnerability

Using Demographic and Health Surveys from 48 low-income and middle-income countries (N = 432,860), we investigated whether or not the presence of symptoms of acute respiratory infection (ARI) are contingent on environmental vulnerabilities such as the region, the level of ambient air pollution, community orphanhood status, and household poverty among young children under five. In addition, we also examined whether such an effect may be a consequence of socioeconomic development and/or lifestyle. Using multilevel logistic regression models, environmental vulnerability was found to be significantly associated with the likelihood of childhood ARI symptoms and this association seemed to be related to the level of ambient air pollution. Our findings suggest that important roles are played by both geographic region and ambient air pollution, and that these factors may disproportionately shape a child's risk of ARI symptoms in a global context.