Birth Cohort in Rahimyar Khan, Pakistan
Condition: Child Mortality; Child Morbidity; Child Development; Child Behaviour
Study type: Observational

Summary: 
      In 2010, 7.6 million children under the age of five died worldwide and yet the causes of only
      2.7% (0.205 million) of these deaths were medically certified. A thorough understanding of
      the causes of child mortality is necessary to guide research efforts aimed at tackling this
      important global health problem. Prospective birth cohort studies present an opportunity to
      examine the relationships between early-life exposures and multiple health and non-health
      related outcomes including death, illness, and socioeconomic factors. In this study, we will
      provide insight into the underlying causes of child mortality by collecting high-quality data
      on early-life exposures and health and non-health related outcomes in the first year of life.
    

Detailed description: 
      In 2010, 7.6 million children under the age of five died worldwide (Liu et al., 2012).
      Notably, the burden of under-five mortality varies dramatically by country. The majority of
      total child deaths in 2010 were seen in Africa (3.6 million) and southeast Asia (2.1 million
      deaths), compared to 0.16 million and 0.28 million under-five deaths in Europe and the
      Americas, respectively (Liu et al., 2012). Strikingly, nearly half of the world's under-five
      child deaths in 2010 could be attributed to only five countries: India, Nigeria, Democratic
      Republic of the Congo, Pakistan, and China (Liu et al., 2012). In Pakistan alone, over
      420,000 under-five child deaths occurred in 2010 (Liu et al., 2012).

      A thorough understanding of the etiology of child mortality is necessary to guide research
      efforts aimed at tackling this important global health problem. Importantly, in 2010, the
      causes of only 2.7% (0.205 million) of all deaths in children under the age of five were
      medically certified (Liu et al., 2012), highlighting the need to gather high-quality data on
      the causes of mortality.

      Prospective longitudinal birth cohort studies present an opportunity to examine temporal
      relationships between early-life exposures (i.e. prenatal, pregnancy, and early postnatal
      exposures) and multiple health and non-health related outcomes including mortality,
      morbidity, and socioeconomic position. It is well documented that exposures that occur early
      in life, including genetic, environmental, socioeconomic, and lifestyle factors, may have
      long-lasting effects on growth, development, and health outcomes throughout an individual's
      entire life course (Lynch & Smith, 2005). Thus, data on exposures during pregnancy and early
      childhood are valuable and may provide clues to the etiology of long-term outcomes.

      Additional value can be gained through cross-cohort collaborations and comparisons (Larsen et
      al., 2013)(Paternoster et al., 2012)(Brion et al., 2011). By pooling data from multiple
      cohort studies, causal inferences can be made with greater confidence. In addition, through
      cross-country comparisons, heterogeneity in exposures is often increased making it more
      likely that an association between exposure and outcome will be observed. Similarly,
      cross-cohort comparisons enable researchers to investigate patterns associated with health,
      social, and economic outcomes in distinct regions of the world. These types of analyses may
      provide valuable insight into the underlying causes of global health inequalities.

      The objective of this study is to implement a longitudinal prospective birth cohort study in
      Pakistan to obtain extensive and high-quality information on early-life exposures and health
      and non-health related outcomes in the first year of life. Concurrent to the design and
      implementation of this cohort study in Pakistan, similar studies are being implemented in
      Kenya (Coastal Region Cohort, Lead PI: Dr. Shaun Morris), Brazil (Pelotas Cohort, Lead PIs:
      Dr. Pedro R.C. Hallal, Dr. Diego G. Bassani and Dr. Mariangela Silveira), and South Africa
      (Birth to Twenty Cohort, Lead PI: Dr. Shane Norris). The investigators of each project have
      communicated their intent to align study materials in an effort to increase the ease of
      future comparisons between findings. This study will therefore be one crucial pillar in a
      multi-country cross-cohort comparison and presents a unique opportunity to investigate and
      compare the patterns that shape health and non-health related outcomes in individuals from
      four distinct regions in the world.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        This study will be conducted in Rahimyar Khan (RYK) in Punjab Province, Pakistan and
        follows a longitudinal birth cohort design that will be conducted alongside a
        community-based, cluster randomized intervention trial in RYK (NCT02130856). In the
        concurrent intervention trial, approximately 6000 pregnant women and their unborn babies
        will be enrolled to participate in either the control or intervention arm of the trial;
        approximately half of the women will be enrolled to the control arm and half will be
        enrolled to the intervention arm. At the time of enrolment, women in the control arm of the
        trial will also be asked to participate in the birth cohort study.
      
Keywords: Birth cohort; Pakistan; Child mortality