Single parent status and children's objectively measured level of physical activity.

Background: Single-parent family status has been investigated as a possible psychosocial determinant of children's level of physical activity (PA)-although with mixed and inconclusive results. Prevailing evidence of the importance of two-parent family status as a resource for children's PA is based on a mix of subjective and objective measurements of PA. Objectives: To investigate if the level of PA among children living with a single parent was lower compared to children living with two parents by means of a meta-analysis of published and unpublished studies. We restricted our analysis to studies with objective measurements of PA.

Methods: Data sources: The databases, Social Science Citation Index, PsycINFO, PubMed, and EBSCO were searched (1987-2013). Study eligibility criteria: Observational studies comparing objectively measured PA between single-parent children and children from two-parent families. Study appraisal and synthesis methods: We used guidelines from the and a modified version of the Newcastle-Ottawa Scale overall to assess the quality of the included studies. We refrained from calculation of summary scores.

Results: Twelve studies met the following inclusion criteria of which six were unpublished: (a) child age (6-18 years) and (b) objectively measured level of PA. Meta-analysis revealed pooled estimates of -0.01 for boys (95 % CI -0.04-0.03,  = 0.77,  = 6.5 %,  = 0.38) and 0.01 for girls (95 % CI -0.03-0.04,  = 0.62,  = 21.0 %,  = 0.24), respectively. Estimates show no differences in objectively measured physical activity between children living in single-parent families compared to children living with two parents. Analyses investigating seven potential moderators did not yield any statistical significant effect size estimates. No evidence of heterogeneity between studies was observed. Limitations: Retrieved articles were assessed by several of the authors. Blinding of the authors was not feasible, as most of the authors have been involved in the studies.

Conclusions: No evidence was found suggesting that children of single-parent families are in special need of extraordinary measures to facilitate their level of PA.