Somatic symptom burden and distress in post COVID-19 and persistent physical symptoms: Evidence from combined SSD-12 and PHQ-15 factor analysis.

BACKGROUND AND AIM: Post COVID-19 condition (PCC) and persistent physical symptoms (PPS) may involve overlapping symptom presentations. We examined whether symptom-related dimensions differ or overlap between PCC and functional somatic disorders by comparing Somatic Symptom Disorder-B Criteria Scale (SSD-12; cognitive-affective distress) and the Patient Health Questionnaire-15 (PHQ-15; somatic symptom burden), and by performing a joint factor analysis of their items.

METHODS

Two cohorts at Helsinki University Hospital were analysed: the Sympa cohort (2020-2024), comprising patients with PPS, and the Long Covid (LC) cohort (2021-2023), including patients with PCC and age- and sex-matched controls.

RESULTS

The study included 557 patients with PPS, 433 with PCC, and 197 controls; two-thirds of patients in both cohorts were female. Patients showed markedly higher somatic symptom burden than controls, with 52.2% of patients with PPS and 48.0% of those with PCC exceeding the combined SSD-12 and PHQ-15 threshold indicating concurrent high somatic symptom burden and symptom-related distress. Joint factor analysis revealed a four-factor structure: one dominant cognitive-affective distress factor; a narrower persistence-worry factor; and two symptom clusters reflecting pain/gastrointestinal and autonomic-neurological symptoms. Participants above the threshold had poorer quality of life, lower resilience, and more comorbidities and symptoms across cohorts (all p < 0.001).

CONCLUSIONS

Approximately half of rehabilitation clinic patients with PPS or PCC exhibited high somatic symptom burden and symptom-related distress. Despite differing clinical entry points, the two cohorts showed broadly similar symptom-related dimensions. High symptom-related distress identifies a subgroup with greater impairment who may benefit from targeted rehabilitation approaches.