Four chronic conditions are more common in patients with Long COVID. Patients with Long COVID reported significantly higher rates of musculoskeletal, respiratory, neurological, and mental health conditions specifically, compared to those without Long COVID (see Figure 9). The rates of respiratory (22% versus 13%) and neurological (10% versus 6%) disease in patients with Long COVID are almost double those reported by those without Long COVID. Conversely, patients with Long COVID had significantly lower rates of diabetes and cancer. There was no significant difference in rates of hypertension, cardiovascular disease, dementia or kidney disease, according to Long COVID status. When analysed separately by gender, higher rates of the same chronic conditions were reported by both genders.
The prevalence and impact of Long COVID in the primary care population
Note: * indicates chronic conditions with a statistically significant higher prevalence among Long COVID patients.
Source: OECD PaRIS 2024 Database.
People may be more susceptible to certain subtypes of Long COVID if they have pre‑existing chronic conditions (Wang et al., 2025[18]). The higher prevalence of musculoskeletal, respiratory and neurological disease among Long COVID patients is consistent with findings reported in the medical literature (Canas et al., 2023[23]; Subramanian et al., 2022[4]). These chronic conditions over-represented in patients with Long COVID likely reflect symptom clustering into the three main subtypes of Long COVID: cardiorespiratory syndrome, neurocognitive syndrome, and musculoskeletal inflammatory syndrome (Kenny et al., 2022[24]; Deer et al., 2021[25]; Wang et al., 2025[18]). Clustering likely represents pre‑existing chronic conditions that increase the risk of developing Long COVID subtypes, as well as the multiple manifestations of Long COVID affecting different organ systems.
The PaRIS survey recruited only participants who had a primary care consultation in the previous six months. This may exclude certain subpopulations who lack access to, who consult very infrequently, or who bypass primary care for other healthcare providers. Thus, reported Long COVID prevalence and outcomes are not representative of the general population, but rather of the typical primary care population. Depending on the OECD country, this representativity is likely to vary with coverage and utilisation of primary care. The survey population excludes patients aged under 45 and so does not assess Long COVID in the younger population. If prevalence changes with younger age, then the overall prevalence in the primary care population surveyed may be an under or overestimate. Long COVID status is based on patient-reported symptoms, without confirmation from medical records, and may be subject to information biases.
Due to the cross-sectional study design, it is not possible to estimate risk of Long COVID, but instead the prevalence of those who have ever had, or currently have, persisting symptoms in 2023 among people who visited primary care services. On the contrary, the assessment of other symptoms and health outcomes, such as severe fatigue, self-rated physical and mental health, and trust in healthcare are assessed at the time of survey completion. As a result, any associations with health outcomes and experiences such as these may not necessarily overlap with the time in which a person had Long COVID. Thus, causality from Long COVID cannot be established, merely association.
The findings reported by PaRIS are coherent with the findings in the published medical literature on Long COVID prevalence and risk factors. The large study population of 103 000 patients provides statistically robust international estimates, and the multicentre study design and multilevel model limit the effect of selection bias due to the effect of the country and primary care providers sampled. The multi-country survey provides updated international Long COVID prevalence estimates in the primary care population in 2023, accounting for new SARS‑CoV‑2 infections and thus new Long COVID cases, across 16 OECD countries worldwide. The findings highlight the considerable disease burden due to Long COVID consistently reported across OECD countries, allowing for international comparison.