Association of the Labor Migration of Parents With Nonsuicidal Self-injury and Suicidality Among Their Offspring in China

IMPORTANCE The labor migration of parents in China often leaves children behind, which may be adversely associated with children's health. However, few studies have assessed the association of parental migration with nonsuicidal self-injury (NSSI) or with suicidality among their offspring. OBJECTIVE To examine the associations of parental labor migration with NSSI and with suicidality as well as potential differential associations by sex among offspring left behind. DESIGN, SETTING, AND PARTICIPANTS This nationwide cross-sectional study was conducted from February to October 2015 among individuals aged 11 to 20 years from 45 public middle and high schools across 5 provinces of China. Data analysis was performed from November 1, 2020, to March 1, 2021. EXPOSURES Parental labor migration, including parental migration status (yes vs no), migration pattern (father, mother, or both), and the child's age at the initial parent-child separation. MAIN OUTCOMES AND MEASURES Less frequent (1-4 episodes) NSSI, more frequent (>= 5 episodes) NSSI, suicidal ideation, and suicide attempt in the past year were measured using validated questionnaires. Multinomial or binomial logistic regression analyses were used separately to estimate adjusted odds ratios (aORs) and 95% CIs of the associations between parental migration and NSSI, suicidal ideation, or suicide attempt. Potential covariates (demographic, family-level, and psychological characteristics) were adjusted for in 3 sequential models. RESULTS A total of 15 312 participants (7904 male [51.6%] and 7408 female [48.4%]) aged 11 to 20 years (mean [SD] age, 15.1 [1.8] years) were included. Of those participants, 5963 (23.3%) experienced parental migration. The 12-month prevalence of less frequent NSSI was 17.2% (2635 of 15 312), the 12-month prevalence of more frequent NSSI was 11.6% (1783 of 15 312), the 12-month prevalence of suicidal ideation was 15.2% (2335 of 15 312), and the 12-month prevalence of suicide attempt was 3.5% (535 of 15 312). Parental migration was associated with less frequent NSSI (adjusted odds ratio [aOR], 1.13; 95% CI, 1.03-1.24); no significant association of parental migration with more frequent NSSI (aOR, 1.01; 95% CI, 0.90-1.13), suicidal ideation (aOR, 1.00; 95% CI, 0.90-1.10), or suicide attempt (aOR, 1.09; 95% CI, 0.90-1.33) was identified. Compared with children whose parents did not migrate, the aOR for less frequent NSSI for participants whose father migrated was 1.18 (95% CI, 1.06-1.31), and the aOR for less frequent NSSI for participants having both parents migrate was 1.12 (95% CI, 1.01-1.28). Compared with children whose parents did not migrate, participants who experienced initial separation from 1 or both parents at preschool age had an aOR for less frequent NSSI of 1.16 (95% CI, 1.03-1.31). No sex disparities were found in these associations except for participants who experienced initial separation from 1 or both migrant parents at preschool age, for which the aOR for more frequent NSSI was higher among male (aOR, 1.27; 95% CI, 1.04-1.55) than female (aOR, 0.96; 95% CI, 0.77-1.19) participants. CONCLUSIONS AND RELEVANCE This cross-sectional study found that parental migration, mainly of the father or of both parents, or an initial separation of children at preschool age from 1 or both parents who migrated was associated with higher odds of experiencing 1 to 4 NSSI episodes in 1 year among offspring. Overall, the associations of parental migration with NSSI and suicidality were similar between male and female participants.