Health impacts of parental migration on left-behind children and adolescents: a systematic review and meta-analysis

Abstract

Background: Globally, a growing number of children and adolescents are left behind when parents migrate. We investigated the effect of parental migration on the health of left behind-children and adolescents in low-income and middle-income countries (LMICs).

Methods: For this systematic review and meta-analysis we searched MEDLINE, Embase, CINAHL, the Cochrane Library, Web of Science, PsychINFO, Global Index Medicus, Scopus, and Popline from inception to April 27, 2017, without language restrictions, for observational studies investigating the effects of parental migration on nutrition, mental health, unintentional injuries, infectious disease, substance use, unprotected sex, early pregnancy, and abuse in left-behind children (aged 0-19 years) in LMICs. We excluded studies in which less than 50% of participants were aged 0-19 years, the mean or median age of participants was more than 19 years, fewer than 50% of parents had migrated for more than 6 months, or the mean or median duration of migration was less than 6 months. We screened studies using systematic review software and extracted summary estimates from published reports independently. The main outcomes were risk and prevalence of health outcomes, including nutrition (stunting, wasting, underweight, overweight and obesity, low birthweight, and anaemia), mental health (depressive disorder, anxiety disorder, conduct disorders, self-harm, and suicide), unintentional injuries, substance use, abuse, and infectious disease. We calculated pooled risk ratios (RRs) and standardised mean differences (SMDs) using random-effects models. This study is registered with PROSPERO, number CRD42017064871.

Findings: Our search identified 10 284 records, of which 111 studies were included for analysis, including a total of 264 967 children (n=106 167 left-behind children and adolescents; n=158 800 children and adolescents of non-migrant parents). 91 studies were done in China and focused on effects of internal labour migration. Compared with children of non-migrants, left-behind children had increased risk of depression and higher depression scores (RR 1·52 [95% CI 1·27-1·82]; SMD 0·16 [0·10-0·21]), anxiety (RR 1·85 [1·36-2·53]; SMD 0·18 [0·11-0·26]), suicidal ideation (RR 1·70 [1·28-2·26]), conduct disorder (SMD 0·16 [0·04-0·28]), substance use (RR 1·24 [1·00-1·52]), wasting (RR 1·13 [1·02-1·24]) and stunting (RR 1·12 [1·00-1·26]). No differences were identified between left-behind children and children of non-migrants for other nutrition outcomes, unintentional injury, abuse, or diarrhoea. No studies reported outcomes for other infectious diseases, self-harm, unprotected sex, or early pregnancy. Study quality varied across the included studies, with 43% of studies at high or unclear risk of bias across five or more domains.

Interpretation: Parental migration is detrimental to the health of left-behind children and adolescents, with no evidence of any benefit. Policy makers and health-care professionals need to take action to improve the health of these young people.

Funding: Wellcome Trust.

Figure 1

Study selection *Some studies included more than one outcome.

Figure 2

Quality assessment of studies included in the systematic review Scoring was based on an adapted version of the Newcastle Ottawa Scale incorporating items from the National Institute for Clinical Excellence Quality Appraisal. Studies with a high or unclear risk of bias across five or more domains were defined as being at high risk of bias overall.

Figure 3

Harvest plot of health outcomes among left-behind children and children of non-migrant parents included in the systematic review Each full-height bar represents the health outcomes reported by an individual study included in the systematic review. Half-height bars represent studies which found varying directionality of health outcomes between different population subgroups (eg, a higher risk among girls who were left behind but no difference among boys who were left behind compared with children of non-migrant parents). Numbers refer to study references as cited in the reference list. Nine studies, , , , , , , , were excluded from this plot due to the absence of significance testing reported in these studies. Two studies, were included for those outcomes for which significance testing was reported and excluded for other outcomes.

Figure 4

Forest plots of relative risks or standardised mean differences for health outcomes Data are presented for mental health binary outcomes (A), mental health continuous outcomes (B), nutrition binary outcomes (C), nutrition continuous outcomes (D), and substance use, abuse and injury outcomes (E). Weights were assigned by random effects analysis. RR=relative risk. SMD=standardised mean difference.

Figure 4

Forest plots of relative risks or standardised mean differences for health outcomes Data are presented for mental health binary outcomes (A), mental health continuous outcomes (B), nutrition binary outcomes (C), nutrition continuous outcomes (D), and substance use, abuse and injury outcomes (E). Weights were assigned by random effects analysis. RR=relative risk. SMD=standardised mean difference.

Figure 4

Forest plots of relative risks or standardised mean differences for health outcomes Data are presented for mental health binary outcomes (A), mental health continuous outcomes (B), nutrition binary outcomes (C), nutrition continuous outcomes (D), and substance use, abuse and injury outcomes (E). Weights were assigned by random effects analysis. RR=relative risk. SMD=standardised mean difference.

Figure 4

Forest plots of relative risks or standardised mean differences for health outcomes Data are presented for mental health binary outcomes (A), mental health continuous outcomes (B), nutrition binary outcomes (C), nutrition continuous outcomes (D), and substance use, abuse and injury outcomes (E). Weights were assigned by random effects analysis. RR=relative risk. SMD=standardised mean difference.