Severity, predictors and clinical correlates of Post-COVID syndrome (PCS) in Germany: A prospective, multi-centre, population-based cohort study

Abstract

BACKGROUND: Post-COVID syndrome (PCS) is an important sequela of COVID-19, characterised by symptom persistence for >3 months, post-acute symptom  development, and worsening of pre-existing comorbidities. The causes and public  health impact of PCS are still unclear, not least for the lack of efficient means  to assess the presence and severity of PCS. METHODS: COVIDOM is a  population-based cohort study of polymerase chain reaction (PCR) confirmed cases  of SARS-CoV-2 infection, recruited through public health authorities in three  German regions (Kiel, Berlin, Würzburg) between November 15, 2020 and September  29, 2021. Main inclusion criteria were (i) a PCR confirmed SARS-CoV-2 infection  and (ii) a period of at least 6 months between the infection and the visit to the  COVIDOM study site. Other inclusion criteria were written informed consent and  age ≥18 years. Key exclusion criterion was an acute reinfection with SARS-CoV-2.  Study site visits included standardised interviews, in-depth examination, and  biomaterial procurement. In sub-cohort Kiel-I, a PCS (severity) score was  developed based upon 12 long-term symptom complexes. Two validation sub-cohorts  (Würzburg/Berlin, Kiel-II) were used for PCS score replication and identification  of clinically meaningful predictors. This study is registered at  clinicaltrials.gov (NCT04679584) and at the German Registry for Clinical Studies  (DRKS, DRKS00023742). FINDINGS: In Kiel-I (n = 667, 57% women), 90% of  participants had received outpatient treatment for acute COVID-19. Neurological  ailments (61·5%), fatigue (57·1%), and sleep disturbance (57·0%) were the most  frequent persisting symptoms at 6-12 months after infection. Across sub-cohorts  (Würzburg/Berlin, n = 316, 52% women; Kiel-II, n = 459, 56% women), higher PCS  scores were associated with lower health-related quality of life  (EQ-5D-5L-VAS/-index: r = -0·54/ -0·56, all p < 0·0001). Severe, moderate, and  mild/no PCS according to the individual participant's PCS score occurred in  18·8%, 48·2%, and 32·9%, respectively, of the Kiel-I sub-cohort. In both  validation sub-cohorts, statistically significant predictors of the PCS score  included the intensity of acute phase symptoms and the level of personal  resilience. INTERPRETATION: PCS severity can be quantified by an easy-to-use  symptom-based score reflecting acute phase disease burden and general  psychological predisposition. The PCS score thus holds promise to facilitate the  clinical diagnosis of PCS, scientific studies of its natural course, and the  development of therapeutic interventions. FUNDING: The COVIDOM study is funded by  the Network University Medicine (NUM) as part of the National Pandemic Cohort  Network (NAPKON).