Frequent Pain and Insomnia Symptoms in Older Indian Couples: Actor, Partner, and Joint Associations.

Pain and sleep symptoms commonly co-occur in later life, but their interdependence within couples remains understudied in low- and middle-income settings. This study analyzed cross-sectional dyadic data from Wave 1 of the Longitudinal Ageing Study in India, including 6,382 cohabiting opposite-sex married couples in which both partners were aged 60 years or older. The outcome was any frequent insomnia symptom-difficulty initiating sleep, difficulty maintaining sleep, or early-morning awakening-reported on at least 5 nights per week. Survey-weighted logistic models with couple-clustered standard errors estimated associations of respondent and spouse frequent pain with the respondent's outcome. In the primary model, respondent frequent pain was associated with higher odds of the outcome when spouse pain was absent (odds ratio, 3.12; 95% confidence interval, 2.53-3.83), whereas spouse frequent pain showed a smaller association when respondent pain was absent (odds ratio, 1.41; 95% confidence interval, 1.11-1.79). Adjusted probabilities were 7.03% when neither partner reported frequent pain, 9.58% for spouse-only pain, 18.69% for respondent-only pain, and 16.11% when both partners reported frequent pain. The additive interaction contrast was -5.13 percentage points (95% confidence interval, -8.70 to -1.56), indicating a subadditive joint pattern. Respondent pain was the dominant correlate, whereas spouse pain contributed a smaller conditional association. Longitudinal studies are needed to establish temporal direction. PERSPECTIVE: This survey-weighted dyadic analysis found that frequent pain was associated with frequent insomnia symptoms within respondents and, more modestly, across spouses. Considering pain in both partners may support couple-aware assessment, although these cross-sectional findings do not establish temporal direction, mechanisms, or treatment effects.