Adults with congenital heart disease overestimate their physical activity level

Background: Physical activity reduces the risk of acquired cardiovascular disease, which is of great importance in patients with congenital heart disease (CHD). There are diverging data whether physical activity level (PAL) differs between patients with CHD and controls. Furthermore, it is unknown if PAL can be reliably assessed in patients with CHD using self-reported instruments. Methods: Seventy-five patients with CHD (mean age 37.5 ± 15.5 years, women n = 29 [38.7%]) and 42 age and sex matched controls completed the International Physical Activity Questionnaire (IPAQ) and carried the activity monitor Actiheart over 4 days. Time spent at ≥3 METS ≥21.4 min/day, i.e. reaching the WHO recommendation for PAL to promote health, was used as the outcome measure. Data on PAL obtained from IPAQ were compared with Actiheart. Results: The proportion of individuals reaching target PAL according to IPAQ was similar in patients with CHD and controls (70.7%vs.76.2%, p = 0.52) as well as between patients with simple and complex lesions. There was an overall difference between IPAQ and Actiheart in detecting recommended PAL (72.6%vs.51.3%, p < 0.001). In a subgroup analysis, this difference was also detected in patients but was borderline for controls. The negative predictive value for IPAQ in detecting insufficient PAL was higher in patients than in controls (73%vs.40%). Conclusions: The proportion of persons reaching sufficient PAL to promote health was similar in patients and controls. The self-reported instrument overestimated PAL in relation to objective measurements. However, with a high negative predictive value, IPAQ is a potentially useful tool for detecting patients with insufficient PAL