Background
Simple self-assessment questions on health status and physical performance might be helpful tools to assess physical capacity in the general population. We quantified the association of self-reported health status and physical fitness with measured physical performance in the general population.

Methods
The prospective Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB) cohort study investigates a representative sample of residents of the City of Würzburg, Germany, aged 30 to 79 years, without a history of HF. The 6-minute walk distance (6MWD) as an objective measure of physical performance was assessed in a 15-m hallway under strictly standardized conditions. Further, all participants were asked to fill in a questionnaire: the answer to question #1 (“how would you describe your health status in general?”) was categorized into “excellent” (excellent or very good), “good” (good) and “poor” (fair or poor). Question #2 asked about a potential impairment in daily physical activities; answers were categorized as follows: “excellent” (no limitation of physical activity), “limited” (minor limitation, e.g. when climbing one flight of stairs/walking one block), and “moderate” (all other participants). We determined the association of the different categories with 6MWD applying a generalized linear model.

Results
We here report on 2952 individuals with valid 6MWD: 52% women; mean age 58±11 years. Prevalence of self-reported “excellent”, “good” and “poor” general health was 38% (54% men, 54±11 years), 53% (45% men, 60±11 years), and 9% (43% men, 61±10 years), respectively. Prevalence of self-reported “excellent”, “moderate”, and “limited” physical fitness was 42% (53% men, 53±11years), 50% (45% men, 60±10 years), and 9% (38%men, 64±10 years), respectively. 6MWD in the different categories of self-reported general health (best to worst category) was 572±72 m, 527±85 m, and 492±104 m, respectively (p<0.001; fig. 1a). 6MWD in the different categories of physical fitness (best to worst category) was 573±75 m, 529±80 m, and 462±104 m, respectively (p<0.001; fig. 1b), without differences between men and women (all p>0.05).

Conclusions
In a representative sample of the general population, we found a strong association between self-reported and objective physical performance and general health. This implies a valid self-perception of the current health status and encourages the use of simple self-assessment questions in primary prevention and screening on a population level. Our results require validation in other population-based cohorts as well as in patient collectives.