Long-COVID symptom burden and the experience of adversity: the importance of response-shift effects over 3 years of the pandemic.

Background/objectives: Long COVID is a long-term legacy of the global pandemic. This study aimed to illuminate how Long COVID impacts individuals, and how response-shift effects influence Long COVID's impact. Methodologically, it expands the application of longitudinal statistical methods to test a more dynamic investigation of psychosocial factors in health over time.

Methods: This quasi-experimental longitudinal cohort study collected data up to four times over 3 years of the COVID pandemic (May 2020 to April 2023). This study focused on 1151 participants divided into four Long-COVID Symptom Burden groups (Never Had COVID; Low, Medium, and High Long-COVID Symptom Burden). It examined COVID-specific outcomes: General Hardship, Healthcare Hardship, Worry, and Social Support. The Quality of Life Appraisal Profile_v2-Short Form assessed cognitive-appraisal processes. Direct and moderated response-shift effects were tested using longitudinal mixed models that examined main effects and interactions of individuals' changes in cognitive-appraisal processes from their usual, over time, and by group over time, after adjusting for sociodemographic covariates and individual's usual appraisal processes, and considering the impact of multiple comparisons.

Results: Notable response-shift effects were revealed on all four COVID-specific outcomes, reflecting both direct and moderated response-shift effects. The experience of COVID-specific adversity was related to various appraisal processes but the nature of the relationship often varied by Long-COVID symptom burden. The appraisal processes that were most salient included patterns of emphasis related to getting used to and handling demands or recent changes, problem-solving goals, and comparing oneself to similar others. Individuals in the high Long-COVID Symptom-Burden Group were particularly highlighted in response-shift effects. The broad conclusions of both raw and multiplicity-adjusted results were similar. That is, there were notable reprioritization and reconceptualization response-shift effects for all outcomes, and notable but fewer recalibration response-shift effects.

Conclusions: Response-shift effects, measured via the direct assessment of cognitive-appraisal processes, were prominent in dealing with the COVID pandemic. The present study documented that COVID-specific adversity can be attenuated or exacerbated depending on individuals' patterns of emphasis, goals, and standards of comparison. The study's utilization of data collected at four time points over 3 years of the global pandemic provided a more comprehensive and far-reaching evaluation of response shift than earlier work. The theory-driven analytic methodology developed in the present work facilitated a more nuanced description of direct and moderated response-shift effects.