Development and Validation of the Long Coronavirus Disease (COVID) Symptom and Impact Tools: A Set of Patient-Reported Instruments Constructed From Patients' Lived Experience

Background To develop and validate patient-reported instruments, based on patients' lived experiences, for monitoring the symptoms and impact of long coronavirus disease (covid). Methods The long covid Symptom and Impact Tools (ST and IT) were constructed from the answers to a survey with open-ended questions to 492 patients with long COVID. Validation of the tools involved adult patients with suspected or confirmed coronavirus disease 2019 (COVID-19) and symptoms extending over 3 weeks after onset. Construct validity was assessed by examining the relations of the ST and IT scores with health-related quality of life (EQ-5D-5L), function (PCFS, post-COVID functional scale), and perceived health (MYMOP2, Measure yourself medical outcome profile 2). Reliability was determined by a test-retest. The patient acceptable symptomatic state (PASS) was determined by the percentile method. Results Validation involved 1022 participants (55% with confirmed COVID-19, 79% female, and 12.5% hospitalized for COVID-19). The long COVID ST and IT scores were strongly correlated with the EQ-5D-5L (r(s) = -0.45 and r(s) = -0.59, respectively), the PCFS (r(s) = -0.39 and r(s) = -0.55), and the MYMOP2 (r(s) = -0.40 and r(s) = -0.59). Reproducibility was excellent with an interclass correlation coefficient of 0.83 (95% confidence interval .80 to .86) for the ST score and 0.84 (.80 to .87) for the IT score. In total, 793 (77.5%) patients reported an unacceptable symptomatic state, thereby setting the PASS for the long covid IT score at 30 (28 to 33). Conclusions The long covid ST and IT tools, constructed from patients' lived experiences, provide the first validated and reliable instruments for monitoring the symptoms and impact of long covid. We developed the long COVID Symptom and Impact Tools from the experiences of 492 patients, captured during a survey with open-ended questions, and assessed their validity and reliability in a sample of 1022 patients with long COVID.

Automated summary

This study developed and validated a tool for monitoring the symptoms and impact of long-term COVID based on patients' lived experiences. The tool showed strong correlations with health-related quality of life, function, and perceived health, and demonstrated excellent reliability.