Table 2.
Description of follow-up reports
| Location | Follow-up study | Age at follow- up | Eligibility/exclusion criteria for follow-up | Risk of bias in loss to follow-up | % follow-up in control groupa | % follow-up in intervention groupa | Outcome measures |
|---|---|---|---|---|---|---|---|
| Bangladesh JiVitA | West et al. [26] | 6 months | None reported | 5 infants lost to follow-up; assumed to be alive at 180 days | 100 % | 100 % | Mortality assessed at 1, 3 and 6 months |
| Bangladesh MINIMat | Persson et al. [27] | 5 years | None reported | None | No reported losses | No reported losses | Mortality assessed at 5 years |
| Khan et al. [42] | 54 months (monthly to 1 year 3 monthly to 2 years) |
Singletons | None; imputation used for missing data points | 79.9 % of livebirths; 86.5 % of children with birth anthropometry | 78.3 % of livebirths; 87.9 % of children with birth anthropometry | Length or height, weight | |
| Khan et al. [45] | 54 months | Singletons with birth anthropometry | Children lost more likely to be first born and have lower birthweight | 72.3 % children with birth anthropometry | 70.9 % children with birth anthropometry | Mid-upper arm circumference, skinfold thickness, body composition by bioelectrical impedance | |
| Tofail et al. [48] | 7 months | Subgroup of singletons born May 2002 to December 2003 | Small but significant differences in children lost to follow-up; mothers had fewer children, higher haemoglobin and shorter gestation; no significant difference in these between allocation groups | Unable to calculate as the number of deaths is only provided for all allocation groups combined | Unable to calculate as the number of deaths is only provided for all allocation groups combined | Cognition (‘Support test’ and ‘Cover test’) Motor development (Psychomotor Developmental Index of Bayley Scales of Infant Development) Behaviour (modified Wolke in three domains: activity, emotion and vocalization) |
|
| Hawkesworth et al. [46] | 4 years (mean 4.6 years) | Singletons born at term with birth anthropometry | Children lost to follow-up more likely to have been firstborn and their mothers on average ~9 months younger with 6 months longer education | 69.1 % of livebirths; 73.6 % of children with birth anthropometry | 67.9 % of livebirths; 74.0 % of children with birth anthropometry | Blood pressure, kidney size by ultrasound (restricted to individuals born during the second half of MINIMat trial, June 2003 to June 2004), and glomerular filtration rate (restricted to individuals born during first y of MINIMat trial, June 2002 to June 2003) | |
| Burkina Faso | Roberfroid et al. [35] | Monthly to 12 months and 30 months | Singletons | None | 97.8 % | 98.0 % | Length, weight, head, chest and mid-upper arm circumference |
| China | Wang et al. [41] | 3 monthly to 12 months, 6 monthly to 30 months | Subgroup born in middle year of 3.5 years recruitment; congenital disease excluded (n = 3) | Not specified | 84.9 % of selected subgroup | 81.3 % of selected subgroup | Length, weight |
| Li et al. [49] | 3 monthly to 1 year | Subgroup born in middle year of 3.5 years recruitment | Small difference in Apgar scores | 89.7 % of selected subgroup | 88.6 % of selected subgroup | Cognition Mental and Psychomotor development (Bayley Scales of Infant Development) |
|
| Li et al. [50] | 7–9 years | Singletons; children who moved away were excluded | None | 61.0 %b | 60.7 %b | Cognition Mental development (Wechsler Intelligence Scale for Children) |
|
| Guinea Bissau | Andersen et al. [36] | 0–2 years | None reported | Lost to follow-up different for maternal weight, age, height and parity; no difference between trial groups | 77.1 % | 77.8 % | Mortality by routine surveillance every 3 months up to 1 year and every 6 months after 1 year |
| Indonesia | Prado et al. [37] | 42 months | 2369 of 41,839 women enrolled randomly assigned to blood tests; children of 549 of these women who gave birth in a 6 month period | None reported | 94.5 % of selected subgroup | 92.8 % of selected subgroup | Cognition Adapted, validated tests for motor, language, visual attention/spatial, executive and socio-emotional function; adjusted analyses presented: confounders included ‘home observation and measurement of environment’ inventory score, child haemoglobin, mother’s mid-upper arm circumference, birth weight, MMN adherence |
| Mexico | Ramakrishnan et al. [38] | 3 months 24 months |
Singletons; children from antenatal trial subsequently randomised to receive MMN or iron + Vit A | Lost to follow-up younger mothers, more educated and less parous | 24.9 % of livebirths in childhood randomisation control group; 69.3 % of children randomised in childhood control | 26.2 % of livebirths in the childhood randomisation MMN group; 74.2 % of children randomised in childhood control | Height, weight, head circumference |
| Nepal Janakpur | Vaidya et al. [43] | 2–3 years | None reported | Difference in lost to follow-up in maternal education, urban/rural residence and main household occupation | 85.8 % | 86.5 % | Height, weight, head, chest, waist, hip and mid-upper arm circumferences, skinfold thickness, blood pressure |
| Devakumar et al. [39] | 7–9 years | None reported | Small difference in lost to follow-up in maternal education and urban/rural residence | 80.5 % | 79.2 % | Height, weight, body composition by bioelectrical impedance, skinfold thickness, head, chest, waist, hip, mid-upper arm and upper leg circumferences, kidney dimensions, blood pressure | |
| Devakumar et al. [52] | 7–9 years | None reported | Small difference in lost to follow-up in maternal education and urban/rural residence; small number (n = 5) with learning difficulties unable to complete spirometry | 80.5 % | 79.2 % | Spirometry, respiratory illness, asthma | |
| Nepal Sarlahi | Stewart et al. [44] | 6–8 years | 3669 also in subsequent childhood trial of iron, folic acid and zinc | Lost to follow-up more likely to be of Pahadi (hill) ethnicity, have a literate mother and own a radio, and less likely to own cattle | 89.2 % | 91.2 % | Height, weight, mid-upper arm circumference, waist circumference, skinfold thickness |
| Stewart et al. [47] | 6–8 years | 3673 also in subsequent childhood trial of iron, folic acid and zinc | Loss to follow-up did not differ between groups; large number did not complete all tests; children with missing data less likely to be of Pahadi ethnicity or to have had any schooling, and had slightly lower BMI | Overall 84.1 %; number of participants varied for each test or measurement | Overall 85.1 %; number of participants varied for each test or measurement | Metabolic syndrome BMI, waist circumference, blood pressure, HbA1c, urine microalbumin:creatinine, cholesterol, glucose, insulin, homeostasis model assessment |
|
| Christian et al. [51] | 7–9 years | In control group of subsequent iron and zinc pre-school trial; children followed up in this study represent 23 % of live births in relevant allocation groups in the original trial | Main loss to follow-up was exclusion of children taking part in postnatal supplementation trial; children lost more likely to be of Pahadi ethnicity, literate mother, own a radio and less likely to own cattle | 75.2 % of subgroup | 84.2 % of subgroup | Cognition Universal Non-verbal Intelligence Test Movement Assessment Battery for Children Finger-tapping test Executive Function (Stroop Numbers Test, backward digit span, go/no-go) Environment (Middle Childhood Home Observation for the Measurement of the Environment inventory) Maternal intelligence (Raven Coloured Progressive Matrices) |
|
| Christian et al. [40] | 6–8 years | None reported | None reported | 96.1 % | 96.0 % | Mortality |
aDefined as total number measured as a proportion of the total number available for measurement (livebirths minus deaths), as a percentage
bThe percentage excludes 1643 families who have moved out of the area
MMN multiple micronutrient supplement