Correlation of parent-reported physical health-related quality-of-life with quantitatively measured physical function of former critically ill children

Many children admitted to a pediatric intensive-care-unit (PICU) show impaired physical function years later. Testing physical function clinically is time-consuming and expensive, hampering routine follow-up. We investigated whether subjective parent-reported physical health-related quality-of-life correlates with and may replace objectively measured physical function of former PICU-patients. This secondary analysis of the PEPaNIC-RCT included 517 former PICU-patients with physical function tests and parent-reported health-related quality-of-life 4 years later. Parents scored physical function, bodily pain, general health and physical role functioning with questionnaires. Physical function tests included handgrip-strength, timed up-and-go-test, 6-minute-walk-test, and accelerometry. Questionnaire-items and test-scores were correlated with Pearson/Spearman correlation. Parent-reported physical function correlated moderately with daily time in sedentary state (ρ=-0.300, p < 0.0001), daily sedentary bouts (R=-0.330, p < 0.0001) and daily steps/hour monitored (R = 0.303, p < 0.0001), and weakly with handgrip-strength, physical activity energy expenditure, time in certain activity-intensity and daily steps (ρ/R = 0.185–0.289, p ≤ 0.019). Parent-reported general health (ρ/R=-0.228 to 0.296, p ≤ 0.033) and physical role functioning (ρ/R=-0.269 to 0.240, p ≤ 0.038) correlated weakly with roughly the same measured physical functions. Parent-reported bodily pain correlated weakly with daily sedentary bouts (R=-0.143, p = 0.024) and daily steps/hour monitored (R = 0.145, p = 0.022). Correlations among physical function test scores were mostly weak. Several aspects of subjective parent-reported physical health-related quality-of-life correlated with former PICU-patients’ performance on physical function tests. The mostly weak strength of the correlations suggest that interrogated physical function cannot simply replace clinical testing. Nevertheless, when resources for clinical testing are lacking, interrogating physical function could still be valuable to get an idea about long-term physical functioning.