Introduction: As populations continue to age, the need for formal care is increasing. As criteria for formal care services become stricter, older adults with greater health problems may remain at home longer and become increasingly reliant on help from their social networks. Knowledge on how different social network factors affect use of care is limited. This study aimed to analyze 1) how personal outlook and objective and subjective social network factors change over time and 2) how these factors are associated to the use of care among older adults. Methods: Data from 7 follow-up questionnaires from the Swedish Adoption Twin Study of Aging (SATSA) were used, spanning a 23-year period. Individuals older than 55 years at baseline were included. Objective social network measures included: number of neighbors, acquaintances, close friends, confidants, and caregivers. Subjective social networks were measured as the satisfaction with these different contacts. Personal outlook included feelings of loneliness and satisfaction with life. The outcome was measured as self-reported receipt of weekly care. Multivariate logistic regression explored the relationship between social network factors and weekly care. Results: Among the 1,065 older individuals in the sample, changes in social networks were most concentrated in the oldest individuals (85+ years at baseline). Increasing age (p<0.0001) was associated with an increased likelihood of weekly care, while never feeling lonely was associated with a much lower likelihood of weekly care (p=0.034). Conclusion: Age and personal outlook factors are important considerations in formal care needs among older populations.