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Table 2 Details of the studies from south Asia included in the meta-analysis

From: Cognitive and motor outcomes in children born low birth weight: a systematic review and meta-analysis of studies from South Asia

Author (year) Site of recruitment; Type of study Country Study population Sample size Tool(s) used Age at assessment Key outcome(s) Quality score
Chaudhari (1999) [30] Hospital;
Prospective follow up
India Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g followed up till their 6 years of age Children with low BW- 201
Children with normal BW-71
Stanford Binet Intelligence Scale (SBIS)
School report card assessment
At 6 years of age Mean IQ score
- LBW: 94.3 (13.6)
- NBW: 101.38 (10.2)
Proportion with abnormal IQ (score of < 85 score)
- LBW: 17%
- NBW: 5.6%
Proportion with poor school performance (< 35% marks obtained)
- LBW: 12.6%
- NBW: 1.8%
6
Tandon (A)(2000) [31] Hospital; Prospective follow up India Infants with BW ≤2000 g discharged from special care nursery and followed up in high risk clinics; controls were healthy term infants with BW > 2500 g followed in well baby clinics Children with low BW:27
Children with normal BW: 28
Stanford Binet Intelligence Scale (SBIS);
Raven’s Progressive Matrices;
M.E Hertzig method of assessing signs of motor dysfunction
Age range of 5 to 9 years; mean age of 7.0 (SD 1.1) years Mean cognitive score
- LBW: 105.6 (13.4)
- NBW: 116 (11.6)
Proportion with low IQ score (<25th percentile)
- LBW: 18.5%
- NBW: 0.0%
Proportion with signs of motor dysfunction
- LBW: 37%
- NBW: 10.7%
2
Tandon (B)(2000) [31] Hospital; Prospective follow up India Infants with BW ≤2000 g discharged from special care nursery and followed up in high risk clinics; controls were healthy term infants with BW > 2500 g followed in well baby clinics Children with low BW:32
Children with normal BW: 29
Stanford Binet Intelligence Scale (SBIS);
Raven’s Progressive Matrices;
M.E Hertzig method of assessing signs of motor dysfunction
Age range of 9 to 13 years; mean age of 10.6 (SD 1.2) years Mean cognitive score
- LBW: 99.6 (10.8)
- NBW: 110.6 (7.3)
Proportion with low IQ score (<25th percentile)
- LBW: 25%
- NBW: 3.4%
Proportion with signs of motor dysfunction
- LBW: 19%
- NBW: 3.4%
2
Chaudhari (2004) [32] Hospital; Prospective follow up India Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g and followed up till their 12 years of age Adolescents with low BW- 180
Adolescents with normal BW-90
Weschler’s Intelligence Scale;
Movement assessment battery;
School report card assessment
At 12 years of age Mean IQ score
- LBW: 89.5 (16.9)
- NBW: 97.2 (14.1)
Proportion with abnormal IQ (score of < 85)
- LBW: 37.7%
- NBW: 18.8%
Proportion with poor school performance (< 50% marks obtained)
- LBW: 21.6%
- NBW: 10.0%
Mean motor impairment score
- LBW: 9.8 (3)
- NBW: 7.3 (2.9)
4
Juneja (2005) [33] Hospital; Prospective follow up India Term infants < 2000 g and term infants with normal birth weight (> 2500 g) Infants with BW < 2000 g-50
Infants with BW > 2500 g-30
Bayley Scales of Infant Development (BSID II) At 18 months Mean mental development quotient
- < 2000 g: 91.5 (16.9)
- > 2500 g: 102 (8.4)
Mean motor development quotient
- < 2000 g: 93.2 (19.7)
- > 2500 g: 99.5 (10.3)
Proportion with adverse mental development outcome
- < 2000 g: 20%
- > 2500 g: 3.3%
Proportion with adverse motor development outcome
- < 2000 g: 24%
- > 2500 g: 3.3%
2
Taneja (2005) [34] Community; Cross-sectional India Children aged 12 to 18 months enrolled in a randomized controlled trial Children with low BW- 61
Children with normal BW-116
Bayley Scales of Infant Development (BSID II) At 12–18 months of age
Findings of assessment at baseline used
Mean mental development quotient
- LBW: 102.2 (12.26)
- NBW: 102.8 (11.03)
Mean motor development quotient
- LBW: 100.08 (13.97)
- NBW: 101.06 (12.37)
Proportion with abnormal mental score (score of < 85)
- LBW: 4.92%
- NBW: 5.17%
Proportion with abnormal motor score (score of < 85)
- LBW: 13.1%
- NBW: 4.3%
7
Subasinghe (2006) [35] Community; Cross-sectional Sri Lanka Preschool children within the age range of 36–54 months Children with low BW: 12
Children with normal BW: 62
Early Screening Inventory for Preschoolers (ESI-P) 36 to 54 months of age Mean cognitive score
- LBW: 63.35 (14.5)
- NBW: 65.32 (15.7)
Mean gross motor score
- LBW: 62.7 (7.4)
- NBW: 68.81 (18.1)
3
Nair (2009) [36] Hospital; Prospective follow up India Adolescents with known birth weight, follow up done at 13 years of age Adolescents with low BW-183
Adolescents with normal BW-211
Raven’s coloured progressive matrices At 13 years of age Proportion with low IQ score (≤25th percentile)
- LBW: 51.4%
- NBW: 41.7%
4
Sidhu (2010) [37] Community; Cross-sectional India Children aged 2 to 35 months recruited from a urban center Children with low BW: 57
Children with normal BW: 196
Clinical Linguistic Auditory Milestone Scale (CLAMS) 2–35 months of age; mean age of 14.15 months Mean Language Quotient (LQ)a
- LBW: 85.07 (16.6)
- NBW: 94.66 (16.6)
3
Hoque (2012) [38] Hospital; Prospective follow up Bangladesh Newborns discharged from a special care baby unit and followed till 12 months of age Infants with low BW: 25
Infants with normal BW: 80
Bayley Scales of Infant Development (BSID II) At 12 months of age Mean mental score
- LBW: 114.18 (12.80)
- NBW: 117.11 (12.04)
Mean motor score
- LBW: 96.14 (25.12)
- NBW: 108.41 (19.69)
4
Khan (2012) [39] Hospital; Prospective follow up Pakistan Neonates discharged from neonatal intensive care unit and followed till 6 months of age Infants with low BW: 92
Infants with normal BW: 18
Denver Development Screening Test (DDST II) At 6 months of age Proportion with delayed development (development quotient < 60)b
- LBW: 38%
- NBW: 0%
4
Tofail (2012) [40] Community; Secondary data analysis from a randomized controlled trial Bangladesh Live born singletons Low BW infants- 66
Normal BW infants- 183
Bayley Scales of Infant Development (BSID II) At 10 months of age Mean mental index score
- LBW: 99.5 (7)
- NBW: 102.9 (8)
Mean motor index score
- LBW: 96.8 (10)
- NBW: 102.7 (10)
7
Modi (2013) [41] Hospital; Prospective follow up India VLBW admitted to a neonatal intensive care unit prospectively followed till 1 year of corrected age. A cohort of term, birth weight (≥2500 g) infants born during same period was enrolled for comparison. VLBW-37
NBW-35
Developmental Assessment Scale for Indian Infants (DAS II) At 12 months of age Mean mental index score
- VLBW: 92.9 (8.0)
- NBW: 98.4 (6.1)
Mean motor index score
- VLBW: 90.1 (9.6)
- NBW: 96.6 (5.8)
5
Chaudhari (2013) [42] Hospital; Prospective follow up India Infants with BW < 2000 g discharged from Neonatal special care units and full term neonates with BW > 2500 g and followed up till their 18 years of age Adolescents with low BW-161
Adolescents with normal BW-73
Raven’s Progressive Matrices At 18 years of age Mean IQ scorea
- LBW: 39.3 (29.9)
- NBW: 52.5 (29.9)
Proportion with low IQ score (<25th percentile)
- LBW: 24.2%
- NBW: 12.7%
Poor school performance (failed at least in one standard in school)
- LBW: 25.5%
- NBW: 5.5%
4
Avan (2014) [43] Community; Cross-sectional Pakistan Low birth weight and normal birth weight infants Low BW infants-86
Normal BW infants-566
Bayley Scales of Infant Development (BSID II) Within 3 years of age Mean psychomotor development index score
- In low BW: 94.13 (18.13)
- In normal BW: 98.47 (15.84)
6
Nair (2014) [44] Hospital; Prospective follow up India Infants discharged from Neonatal special care units and followed up with 12 months of age Infants with low BW- 170
Infants with normal BW-429
Developmental Assessment Scale for Indian Infants (DAS II) At 12 months of age Mean mental index scorea
- LBW: 107.83 (11.04)
- NBW: 110.51 (8.38)
Mean motor index scorea
- LBW: 99.72 (14.28)
- NBW: 104.17 (10.86)
5
Christian (2014) [45] Community; Prospective follow up Nepal Children aged 7 to 9 years who were part of an earlier nutrition supplementation trial Children with low BW-764
Children with normal BW-1163
UNIT for general intelligence;
Finger tapping test for fine motor
At 7 to 9 years of age (mean age of 8.4 years) Mean Intelligence score (UNIT)
- LBW: 47.6 (9.4)
- NBW: 51.6 (10.1)
Mean fine motor score
- LBW: 35.8 (5.4)
- NBW: 36.9 (5.1)
Mean motor impairment score
- LBW: 9.98 (6.73)
- NBW: 7.62 (5.59)
8
Chattopadhyay (2015) [46] Hospital; Prospective follow up India Newborns discharged from SNCU Children with low BW- 206
Children with normal BW-181
TDSC
DDST II
Visual and hearing assessment
Under 3 years of age Proportion with developmental delay
- LBW: 38.8%
- NBW: 20.9%
4
Singh (2017) [47] Community; Cross-sectional India Children under 2 years of age from an urbanized village Children with low BW- 43
Children with normal BW-153
Ages and Stages questionnaire, 3rd Edition Under 2 years of age Proportion with development delay
- LBW: 16.3%
- NBW: 2.0%
4
Kvestad (2017) [48] Community; Prospective follow up Nepal Infants aged 2–12 months enrolled through a cross-sectional survey and followed up till 5 years of age Children with low BW: 124
Children with normal BW: 193
Ages and Stages Questionnaire, 3rd edition At 5 years of age Mean cognitive score
- LBW: 52.68 (6.9)
- NBW: 51.61 (9.1)
Mean motor score
- LBW: 53.44 (6.1)
- NBW: 53.37 (7.5)
4
  1. BW birth weight, LBW low birth weight, VLBW very low birth weight, NBW normal birth weight, IQ intelligence quotient
  2. aSD calculated using imputation method (http://handbook-5-1.cochrane.org/chapter_7/7_7_3_3_obtaining_standard_deviations_from_standard_errors.htm)
  3. bDevelopmental delay was assessed based on the cumulative score of developmental quotient (DQ) for each of the four domains (i.e. gross motor, language, fine motor and personal/social skills) and dividing by 4. A score of < 60 were labelled as “developmentally delayed”. DQ was calculated as, (developmental age/corrected chronological age)*100. Developmental age was established depending on the degree of achievement in each domain; UNIT-Universal Nonverbal Intelligence Test; CO = − cohort; RCT- randomized controlled trial; TDSC- Trivandrum Developmental Screening Chart; DDST- Denver Developmental Screening tool