Table 4 Variable definitions
Variable | Definition and Notes |
|---|---|
<5th percentile for birthweight status | The less-than-5th-percentile birthweight group (referred to as less-than-5th-percentile infants) was a proxy for preterm birth and, in view of the differences in birthweight distributions across the sites, was established separately for each site on the basis of birthweight data for the pretrial year. Site-specific cutoffs were 2450 g for Argentina, 2400 g for Zambia, 2267 g for Guatemala, 2000 g for Belgaum, India, 2150 g for Pakistan, 2000 g for Nagpur, India, and 2500 g for Kenya. Infants were classified as less than 5th percentile on the basis of measured birthweights. Estimated weights by clinical assessment were used when measured weights were unavailable; those missing both estimated and measured weights were classified as less than 5th percentile (since based on historical data, most of the missing data were for preterm infants). |
<25th percentile for birthweight status | We limited this variable to those with measured birthweight. Those with only estimated birthweight or missing birthweight were excluded. We used site-specific cut offs for the 25th percentile for birthweight. |
Preterm/term | The baby’s preterm birth status was calculated using gestational age from last menstrual period and estimated due date. Additionally, we classified or reclassified those with measured birth weight (regardless when measured) greater than or equal to the 95th percentile for weight at 36 weeks gestational age (using site-specific cut offs using WHO weight percentiles calculator that gives gestational age specific distributions http://www.who.int/reproductivehealth/topics/best_practices/weight_percentiles_calculator.xls)) and less than 5500 g as term. 4292 (7 %) of births were coded on weight alone and did not have a GA based on EDD or LMP. This variable resulted in a preterm birth percentage of 11 % of the total population (10 % of live births). |
Gestational age band | Beginning with the preterm variable above, we coded the gestational age bands. We first determined whether the gestational age was “well dated”. Pregnancies dated from the actual date of delivery, with a date that is unknown/estimated or without a method recorded for determining the delivery date were considered not well dated. Pregnancies dated from LMP, clinical exam, USG were considered well dated. If the method of obtaining the delivery date was based solely on LMP, then we kept the gestational age from LMP. Otherwise, if the method was clinical exam or USG, or a combination of LMP and one of these, then we kept the gestational age from EDD. |
Suspected maternal infection | Composite of process outcomes including receipt of antibiotics plus hospital admission or referral, and one or more of the following: receipt of intravenous fluids, surgery, or other treatment related to infection. Additionally, women with postpartum signs and symptoms of severe sepsis with admission to hospital or sepsis as the primary cause of maternal death were included. The definition also included evidence of antepartum or post-partum infection for mothers with infants with a birthweight less than 2500 g. Antepartum infection was defined as: Antepartum hyperthermia ≥38 °C AND (Chorioamnionitis OR Purulent amniotic fluid) OR Postpartum Infection was defined as: Sepsis postpartum OR (postpartum hyperthermia ≥38 °C AND Antibiotics IM or IV AND at least one of the following: surgery site Infection, foul smelling lochia OR any postpartum intervention (Hysterectomy, Curettage/MVA/Evacuation, blood transfusion)). |
Neonatal possible severe bacterial infection (pSBI) | Neonatal symptoms occurring during the first 6 weeks of life and reported in the GN Maternal and Newborn Health (MNH) Registry were used to derive estimates of possible severe bacterial infection (pSBI) based on the WHO Young Infants Clinical Signs Study criteria [Young Infants Clinical Signs Study Group 2008] to the extent possible given the information recorded in the registry. The presence or absence of each of the following symptoms was recorded in the registry, with a “yes” response considered consistent with pSBI: breathing problems/difficulty breathing, feeding problems/stopped suckling/feeding, high fever (>38 °C), hypothermia (<35 °C), convulsions, and bleeding/pus-like discharge from umbilicus. Infants who died with cause of death coded “infection” were also counted as having pSBI. Additionally, text fields used to record information about symptoms and diagnoses as well as cause of death were reviewed. Infants with any of the symptoms listed above, or infection, sepsis, possible sepsis, septic conditions (eg, septic rash, septic cord), meningitis, and/or pneumonia in any of the text fields were counted as having pSBI. The number of pSBI episodes and the exact timing of infection could not be determined, as dates of diagnosis were not recorded. Two of the 63,685 livebirths in the ACT pretrial period are missing pSBI status: one infant with neonatal outcome coded as born alive but cause of death indicated fetal demise (Guatemala, control) and one infant with missing delivery date (Pakistan, intervention). Of the 98,137 livebirths in the trial period, 1459 (1.5 %) are missing pSBI status (intervention: 706, control: 753). The majority (1454) were 2013 births in Pakistan with some or all data collected on revised forms that did not include the symptom questions used to define pSBI. Three other infants with neonatal outcome coded as born alive but with cause of death recorded as fetal demise or macerated stillbirth are missing pSBI status (one from Nagpur, two from Guatemala) and two others from Kenya. Some limitations of this definition include the following, We were unable to match YICSS symptoms completely. Some symptoms, especially breathing problems, were non-specific, as they overlap with viruses, malaria, prematurity, etc. There was a lack of confirmatory tests such as blood cultures or chest x-rays and possibly reporting differences between sites. |
Location of delivery by availability of delivery and neonatal care at the facility | We limited the data to births that either occurred at home or at a facility that is generally used by the women living in the MNH clusters. This included facilities that are physically located within the geographic boundaries of the clusters and facilities that are outside the cluster, but are regularly utilized by the women. For each facility, we determined whether or not each of the following services had been provided to at least two people during the course of the trial: c-section, bag and mask, and oxygen or mechanical ventilation. If so, then the facility was coded as having the service. If not, the facility was coded as not having the service. We could then determine whether each birth occurred at a facility with these services available. The variable has the following levels: • Home birth • Delivered at hospital or clinic with none of the maternal/neonatal capabilities • Delivered at hospital or clinic with some, but not all maternal/neonatal capabilities • Delivered at hospital or clinic with all maternal/neonatal capabilities |