This study investigates a possible model for the relationship between child and parental sleep and parenting stress. We performed post-hoc statistical analyses of longitudinal parent questionnaire data, gathered at regular visits to well-child clinics in south-east Sweden or later at home from unselected parents of about 10,000 children at ages 1, 3 and 5 years old, as part of ABIS (All Babies In Southeast Sweden).
Parent-rated child sleep quality and parenting stress as measured by Swedish Parenting Stress Questionnaire at ages 1, 3 and 5 years; and self-reported parental sleep quality at ages 3 and 5 were dichotomised into poor/not poor sleep and high/not high stress. Odds ratios for the interrelationships between measures were obtained first by cross-tabulation two by two, then by logistic regression including all concurrent and preceding measures. The association of child sleep quality with parenting stress observed at age 3 with crosstabulation was non-significant with logistic regression, whereas the associations of child sleep quality with parental sleep quality and of parental sleep quality with parenting stress remained strong at all ages with odds ratios of about 16-20 or 4.5, respectively (p < 0.001). All measures also showed stability over time, especially parenting stress. Child temperament rating and social support dissatisfaction showed strong associations to sleep/stress measures but including them in logistic regressions did not influence the above relationships. Our data support a model where the associations between poor child sleep and high parenting stress, within and between age groups, is mainly explained by poor parental sleep.