Aim: To validate a single-item screening question for systematic use in primary health care to identify physically inactive adults, who may benefit from physical activity intervention.
Methods: The single-item physical activity screening question was administered to 1171 women aged 51-74 years recruited from 10 general practices, followed by a longer validated physical activity questionnaire (the NZPAQ-LF). Sensitivity, specificity, likelihood ratios, positive and negative predictive values, and a Kappa statistic were calculated to assess validity of the screening question.
Results: The sensitivity of the single-item question was 76.7% (95% confidence interval [CI] 73.5-79.7). It had high specificity (81.1%, 95%CI 77.2-84.4), and a high positive predictive value (86.7%, 95%CI 83.8-89.1). The positive likelihood ratio was 4.05 (3.33-4.93), and negative likelihood ratio was 0.29 (0.25-0.33). The Kappa statistic calculated for the single-item screening question when validated against the NZPAQ-LF was 0.56 (p<0.001).
Conclusions: The single-item screening question has good sensitivity, specificity, and concordance with a validated physical activity questionnaire. The question is easy to administer and elicits a simple yes/no response from patients. This validated tool can now be used in practice to identify women who would benefit from physical activity interventions in primary care.