An exploration into self-reported inactivity behaviours of adults with an intellectual disability using physical activity questionnaires.

Background: Inactivity is a correlate of adverse health. Adults with an intellectual disability (ID) are more inactive than the general population and often present with more complex health issues. Self-reported activity questionnaires such as the International Physical Activity Questionnaire - Short Form (IPAQ-SF) and Rapid Assessment of Physical Activity (RAPA) questionnaire are the predominant source of activity information because of their low cost, non-invasive nature, ease of administration and interpretation of results.

Methods: Correlates of inactivity among the general and ID populations were identified through a literature scoping review. Inactivity was measured using the RAPA and the IPAQ-SF. A multiple-imputation chained equation was used to impute missing data. Using Pearson chi-squared analyses, relationships between these correlates as well as covariates of age, sex, level of ID, body mass index (BMI) and aetiology, and RAPA and IPAQ-SF categories were explored. Logistic regression provided more detailed analyses. Results were summarised using the Systems of Sedentary Behaviour framework. Spearman correlations examined the IPAQ-SF and RAPA relationships.

Results: Three correlates for inactivity emerged from the IPAQ-SF and RAPA questionnaire. Up after 07:00 h was a correlate for both. Difficulty walking 100 yards and epilepsy were additional correlates of inactivity. Weak but significant correlations were seen between IPAQ-SF and RAPA scores.

Conclusions: High inactivity levels are present in adults with an ID. The IPAQ-SF and RAPA questionnaires are weakly correlated.