Adult day programs provide critical supports to both, older adults living in the community, and their family/friend caregivers. This is essential because ensuring high-quality care in the community for as long as possible and avoiding or delaying long-term care home admissions are key priorities of older adults, their caregivers, and healthcare systems. While most older adults in Canada receive care in the community, about 10% of newly admitted nursing home residents have relatively low care needs that could be met in the community with the right supports. Caregivers provide most of the care in the community, which puts them at high risk for caregiver burden. Day programs intend to mitigate these issues by providing respite to caregivers. However, research on the effectiveness of day programs is inconsistent. Generally, the methodological quality of studies is poor, and especially Canadian research is lacking. The research objectives are to (1) explore changes in patterns of day program use (including non-use) between provinces and over time, (2) compare characteristics of older adults with different day program use patterns (including non-use), and (3) assess whether day program attendees compared to a propensity score matched control group of non-attendees have better outcomes. This retrospective cohort study will use population-based clinical and health administrative data of older adults (65+ years) who received publicly subsidized continuing care in the community in Alberta, British Columbia, and Manitoba between January 01, 2012 and December 31, 2024. Patterns of day program use (i.e., variations in time to attend a day program for the first time, and frequency and duration of attendance) and how these patterns vary by province and over time will be assessed. Characteristics of older adults with different patterns of day program use (e.g., no, low, medium, high) will be compared. Characteristics of the participants will include age, sex, dementia status, frailty level, comorbidity status, socioeconomic status, availability of a caregiver, and caregiver distress. Finally, propensity-matched comparison group (by region, age, gender, cognitive/physical impairment, type/duration of community care received previously) of older adults who have not attended a day program will be created. Time-to-event models and general estimating equations will assess whether day program attendees compared to non-attendees enter continuing care facilities later (primary outcome); use emergency, acute, or primary care less frequently; experience less cognitive and physical decline; and have better mental health (secondary outcomes). Models will include day program exposure as an independent variable and will be adjusted for province, participant demographics, medical and functional conditions, caregiver availability/distress, other community services received (e.g., home care, in-home respite), and (if appropriate) matching variables.