Primary Care Records and Population Prevalence of Chronic Insomnia: Do They Match?

Background/Objectives: Chronic insomnia is a prevalent condition with important health implications. However, its recognition in clinical practice is often limited. This study evaluated the alignment between population-based estimates of chronic insomnia and the prevalence recorded in primary care, assessing the diagnostic reliability of healthcare services. Design: We conducted a comparative cross-sectional analysis using two independent data sources: (1) the Epidemiology Study of Insomnia in Spain (EPINSOM) survey, which applied the International Classification of Sleep Disorders, Third Edition (ICSD-3), criteria to a representative sample of the Spanish adult population (n = 2243; Catalonia subsample n = 363) and (2) the SIDIAP Electronic Health Record (EHR) database, comprising anonymized primary care data from adults in Catalonia (N = 4,131,754). Methods: Prevalence estimates of insomnia symptoms, chronic insomnia syndrome, and chronic insomnia disorder were extracted from the EPINSOM survey and compared with ICD-10-coded insomnia diagnoses in the SIDIAP. Pairwise comparisons of proportions were conducted using z-tests for independent samples. For transparency, 95% confidence intervals (CI) were calculated using the Wilson method. Results: In Catalonia, the population-based prevalence of chronic insomnia disorder was 13.6% (95% CI: 10.1–17.1), whereas the prevalence of coded insomnia diagnoses in primary care was significantly lower at 5.1% (95% CI: 5.08–5.12). Among adults aged ≥55 years, the prevalence estimates were more closely aligned between the survey (18.2%) and SIDIAP records (18.5%). The survey-derived prevalence of insomnia symptoms reached 41.39% (95% CI: 39.2–43.6), highlighting substantial underrecognition in clinical practice. Conclusions: Our findings indicate that primary care insomnia diagnoses substantially underestimate insomnia prevalence compared with ICSD-3-based population estimates, particularly in younger adults. While diagnoses appear to be more like to prevalence in older adults (>55 years), this discrepancy highlights the need for improved identification and management of insomnia in primary care settings, especially among younger populations who may be underdiagnosed.