Effective primary care attenuates the association between frailty and hospital admission in old age: the ELSI-Brazil.

Background: Frailty is a multidimensional syndrome leading to a higher hospitalization. However, few studies explicitly analyze whether measures of effective primary care modify the relationship between frailty and hospital admission.

Methods: This cross-sectional study included data from the second wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a representative community-based study with older adults aged 50 years and over, conducted in 2019-2021. Self-reported hospital admission in the past 12 months was the outcome. Frailty included the 5 phenotypic criteria: weight loss, exhaustion, low physical activity, weakness, and slowness. The effective primary care index included 12 attributes indicators, continuously. Statistical analyzes comprised logistic regression.

Results: Among the 7,436 study participants, frailty (odds ratio [OR] 2.17; 95% confidence intervals [95% CI] 1.31-3.62) and effective primary care index (OR 1.10; 95% CI 1.03-1.16) were positively associated with higher hospitalization. Interaction revealed that while effective primary care was positively associated with hospitalization, this association was different among frail older adults (OR 0.80; 95% CI 0.65-0.99). After stratification by frailty status, positive association with hospitalization remained only among prefrail and nonfrail individuals. The predicted probability of hospitalization tended to decrease along with higher primary care index values among frail older adults and became similar to prefrail/nonfrail at the highest end of the scale.

Conclusions: Effective primary care decreases the likelihood of hospital admission among frail older adults. Interventions for delaying frailty should be initiated in primary care along with policies to strengthen primary care's organizational and provider/team-level attributes.