Project Grant F31AG091989

DECOMPOSING COMPONENTS OF SOCIAL ISOLATION AND THEIR EFFECT ON COGNITIVE DECLINE AND DEMENTIA - PROJECT SUMMARY SOCIAL ISOLATION IS AN IMPORTANT TARGET OF INTERVENTION TO REDUCE NEGATIVE HEALTH OUTCOMES, INCLUDING ALZHEIMER'S DISEASE AND RELATED DEMENTIAS (ADRD). REAL-WORLD INTERVENTIONS OFTEN FOCUS ON SPECIFIC DOMAINS AND MODES OF CONTACT (E.G., FRIENDSHIP HOTLINES). HOWEVER, OBSERVATIONAL MEASURES OF SOCIAL ISOLATION OFTEN COLLAPSE ACROSS THESE DOMAINS AND MODES, MAKING IT IMPOSSIBLE TO ANTICIPATE THE IMPACTS OF SPECIFIC TYPES OF INTERVENTIONS ON ADRD. RANDOMIZED CONTROL TRIALS OF SOCIAL ISOLATION INTERVENTIONS ARE LIMITED IN THEIR ABILITY TO ASSESS LONG-TERM OUTCOMES SUCH AS ADRD AND ARE OFTEN ASSESSED BY THEIR IMPACTS ON LONELINESS AS THE PRIMARY OR SOLE OUTCOME. OBSERVATIONAL RESEARCH WITH MEASURES THAT ARE ALIGNED WITH REAL-WORLD INTERVENTIONS IS THEREFORE CRITICAL TO ANTICIPATE THE IMPACTS OF THESE INTERVENTIONS ON ADRD. THIS F31 CAREER DEVELOPMENT PROPOSAL IS DESIGNED TO PREPARE THE CANDIDATE FOR A RESEARCH CAREER FOCUSED ON THIS CRITICAL AREA, DELIVERING MUCH-NEEDED EVIDENCE THAT CAN BE UTILIZED TO INFORM THE DESIGN OF SOCIAL ISOLATION INTERVENTIONS AND ANTICIPATE THEIR POTENTIAL EFFECTS. LEVERAGING LONGITUDINAL DATA (UP TO 16 YEARS OF FOLLOW-UP) AND A ROBUST SAMPLE SIZE (APPROXIMATE N=10,000) FROM THE U.S. HEALTH AND RETIREMENT STUDY, THIS RESEARCH PLAN EVALUATES THE EFFECTS OF UNIQUE DIMENSIONS OF SOCIAL ISOLATION ON COGNITIVE DECLINE AND DEMENTIA. USING LINEAR MIXED EFFECTS MODELS AND ADVANCED SURVIVAL ANALYSIS, AIM 1 EVALUATES THE INDEPENDENT EFFECTS OF ISOLATION FROM FAMILY, FRIENDS, AND COMMUNITY. AIM 2 EVALUATES THE INDEPENDENT EFFECTS OF IN-PERSON, TELEPHONE, AND WRITTEN COMMUNICATION. FINALLY, AIM 3 EXAMINES THE EXTENT TO WHICH LONELINESS MEDIATES THE RELATIONSHIP BETWEEN SOCIAL ISOLATION AND COGNITIVE DECLINE AND DEMENTIA. THIS AIM UTILIZES ADVANCED CAUSAL MEDIATION METHODS THAT OVERCOME LIMITATIONS IN TRADITIONAL METHODS, SUCH AS THE INABILITY TO ESTIMATE EFFECTS ON DICHOTOMOUS OUTCOMES (E.G., COGNITIVE IMPAIRMENT AND DEMENTIA) AND THE INABILITY TO PROPERLY ACCOUNT FOR IMPORTANT EXPOSURE-MEDIATOR INTERACTIONS. THIS RESEARCH WILL DIRECTLY CONTRIBUTE TO THE NIA'S GOAL TO ILLUMINATE PATHWAYS BY WHICH SOCIAL FACTORS AFFECT HEALTH IN OLDER ADULTS. GUIDED BY AN INTERDISCIPLINARY AND EXPERT MENTORSHIP TEAM, THE PROPOSED TRAINING WILL ENHANCE THE CANDIDATE'S KNOWLEDGE OF MEASUREMENT OF SOCIAL ISOLATION AND COGNITION, CLINICAL AND COMMUNITY-BASED OPPORTUNITIES FOR SOCIAL ISOLATION INTERVENTIONS TO REDUCE ADRD, AND ADVANCED CAUSAL INFERENCE METHODS. FACILITATED BY THE SUPPORTIVE TRAINING ENVIRONMENT AT UCSF, EXECUTING THIS F31 RESEARCH AND TRAINING PLAN WILL PREPARE THE CANDIDATE TO SUCCEED IN A CAREER AS AN INDEPENDENT TRANSLATIONAL RESEARCHER IN DEMENTIA EPIDEMIOLOGY.