0359 Comorbid Insomnia and Sleep Apnea: Mortality Trends in a Large National Cohort of US Veterans

Abstract Introduction Comorbid insomnia and sleep apnea (COMISA) is a prevalent condition among veterans. Insomnia and sleep apnea (SA) may be diagnosed concurrently or on separate occasions (e.g., concurrent diagnoses, insomnia first, or OSA first). No study has investigated temporal sequences, time intervals, or health-associations of diagnostic intervals in people with COMISA. We examined these patterns of COMISA diagnoses in a large longitudinal clinical database. Methods We used ICD 9/10 codes to identify veterans with confirmed diagnosis of insomnia or SA. We used previously validated confirmed diagnosis algorithm. For insomnia, we further required evidence of treatment (medications or CBT-I). Time interval between the two diagnoses was defined in months (30 days), delta-month. We calculated the odds ratio of all-cause mortality followed for 36 months adjusting (aOR) for age, sex, race, ethnicity, Charlson Comorbidity Index (CCI) and exposure time (time from index insomnia or SA diagnosis) using patient with concurrent diagnosis as the reference (delta-month=0). Results We identified 303,803 people with COMISA with prevalence of 14.1% (Age 52.5, male 89.2, BMI 32.4±6.1, White 68.3%, CCI≥2 18.5%). 11,396 (3.8%) had both conditions diagnosed concurrently, 153,386 (50.5%) had insomnia followed by later SA diagnoses, and 139,021 (45.7%) had SA followed by later insomnia diagnoses. All-cause mortality rates were lowest among the concurrent diagnosis group (13%) and increased with larger time intervals between diagnoses (either insomnia-first, or OSA-first). Mortality rates increased to 16% from 5 to 14 months and reached 17% in ≥15 months. The aOR for mortality increased with greater delta-month up to 5 months, then plateaued from 5-14 months (1.19±0.03) and further rose and plateaued thereafter (1.24±0.05). Conclusion In COMISA, the timing of each diagnosis is heterogenous and may be associated with health outcomes. Mortality rates increase with wider time intervals between the two diagnoses, regardless of which condition is diagnosed first. Further exploration of mechanisms underlying this association of increased diagnostic delta and higher mortality risk in people with COMISA is warranted. Support (if any) Supported by NIH-NHLBI-K25 funding (#1K25HL152006-01 J.R.); seed funding by AHBPCE (#FY2024-002 J.R.); and Center for Innovations in Quality, Effectiveness, and Safety (CIN 13-413), Michael E. DeBakey VA Medical Center, Houston, TX.