Association between self-reported and objectively assessed physical functioning in the general population

Abstract

Knowledge about a patient’s physical fitness can aid in medical decision-making, but objective assessment can be challenging and time-consuming. We aimed to investigate the concordance of self-reported health status and physical functioning with the 6 minute walking distance (6MWD) as objective measure of physical performance. The prospective characteristics and course of heart failure stages A/B and determinants of progression (STAAB) cohort study iteratively follows a representative sample of residents of the city of Würzburg, Germany, aged 30–79 years, without a history of heart failure (HF). The 6MWD was measured in 2752 individuals (aged 58 ± 11 years, 51% women) from a population-based cohort under strictly standardized conditions. Self-reported health status and physical functioning were assessed from items of the short form 36 (SF-36). After the respective classification of self-reported health status and physical functioning into ‘good’, ‘moderate’, and ‘poor’, we determined the association of these categories with 6MWD by applying a generalized linear model adjusted for age and sex. Prevalence of self-reported good/moderate/poor general health and physical functioning was 41/52/7% and 45/48/7%, respectively. Mean 6MWD in the respective categories was 574 ± 70/534 ± 76/510 ± 87 m, and 574 ± 72/534 ± 73/490 ± 82 m, with significant sex-specific differences between all categories (all p < 0.001) as well as significant differences between the respective groups except for the categories ‘moderate’ and ‘poor’ health status in men. This cross-sectional analysis revealed a strong association between self-reported health status and physical functioning with the objective assessment of 6MWD, suggesting that physicians can rely on their patients’ respective answers. Nevertheless, sex-specific perception and attribution of general health and physical functioning deserve further in-depth investigation. Decision-making based on self-reported health requires prospective evaluation in population-based cohorts as well as adult inpatients.