The strengths of our study should

The strengths of our study should be considered in light of the limitations. NHIS data is cross-sectional, limiting the examination of changes that occur in aerobic activity in the same individual over time. Given the cross-sectional nature of NHIS, we were not able to more definitively establish a causal link between neighborhood social Dorsomorphin and physical activity, such as ruling out reverse causation as a plausible explanation (e.g., individuals who are more physically active help build more socially cohesive neighborhoods), or the related notion of endogeneity where healthier (i.e. more physically active individuals) select neighborhoods that are more socially cohesive. Also, the activity estimates were based on self-reported measures rather than ‘objective’ device measures of activity. Previous research has indicated that the overestimation of the amount of physical activity performed can occur as a result of reporting bias from self-reported physical activity, compared with activity assessed through device measured methods (Troiano, Berrigan, & Dodd, 2008). For example, a recent study of Latinos that examined both self-reported and accelerometer measured physical activity showed that there was an overestimation of physical activity when using self-report versus an objective measure (Arredondo et al., 2015). However, it must be noted that accelerometer-based assessments also induces, to some extent, measurement error as they are based on pre-specified bouts of activity and also do not provide information on domain-specific activity, which was the goal of our study. Further, physical activity recommendations in the 2008 Physical Activity Guidelines for Americans are based on self-reported measures of physical activity (USDHHS, 2008). Also, the measure of aerobic physical activity in our study only focused on LTPA, not accounting for other types of activity such as transportation activity, which may be impacted by neighborhood characteristics such as neighborhood social cohesion. Although Latinos engage in low levels of LTPA, occupational physical activity has been shown to be substantially higher in Latinos compared with other racial/ethnic groups (Marquez et al., 2010), which contributes to overall activity. For example, previous research has shown that based on accelerometer data, Latinos of Mexican origin engage in higher levels of overall activity compared with non-Latino whites and blacks (Troiano et al., 2008). Lastly, another limitation of our study was the use of four neighborhood social cohesion items, rather than the five items typically used to measure neighborhood social cohesion (Sampson et al., 1997). However, we assessed the reliability of the four items as a measure of neighborhood social cohesion and they demonstrated high internal consistency.
Background Raising a child with a disability is an unexpected experience for parents (Raina et al., 2005). Caring for a child with a disability, depending on the type of disability, can result in physical health problems, mental health problems, and time or financial burdens on mothers (Bourke et al., 2008; Brehaut et al., 2004; Estes et al., 2013; Lee, 2013; Montes & Halterman, 2008a, 2008b; Nes et al., 2014; Parish, Rose, Dababnah, Yoo & Cassiman, 2012; Raina et al., 2005). In particular, maternal mental health is important for both mothers and children because poor maternal mental health is related to unfavorable parenting practices (McLennan & Kotelchuck, 2000; Minkovitz et al., 2005), child health problems (Ferro & Speechley, 2009; Schwebel & Brezausek, 2008), and poor school performance (Shen et al., 2016). Mothers play a major role in childrearing, regardless of the presence or absence of a disability. Supporting mothers is a public issue because Japanese society faces a proliferation of nuclear and dual-income families. Paternal involvement in childrearing remains to a small extent in the present circumstances. For example, the parental leave obtainment rate was only 2.0% of full-time working fathers (The Ministry of Health Labour and Welfare, 2012), and fathers seldom commit to household chores and childrearing tasks (i.e., only 39minutes per week in dual-income families) (Statistics Bureau, 2011). Therefore, mothers may experience further negative influence on their mental health in addition to ordinary childrearing tasks.