Prevalence of overlap between frailty, comorbidity, disability and poor self-rated health amongst community-dwelling centenarians in Hong Kong

Abstract

Introduction The frailty phenotype includes five characteristics: fatigue, weakness, poor endurance, physical illness and weight loss. Frailty correlates strongly with comorbidity and disability, but their interaction with self-rated health amongst the oldest-old adults remains unclear. We examined the prevalence of overlap between frailty, comorbidity, disability and poor self-rated health amongst the oldest-old adults. Methods We conducted a cross-sectional community-based centenarian study of 121 community-dwelling Chinese near-centenarians and centenarians. We assessed four major phenomena: 1) Frailty defined as score >2 out of 5 in the FRAIL Questionnaire of the International Academy of Nutrition and Aging (FRAIL-IANA); 2) Disability defined as >1 dependent task in the Instrumental Activities of Daily Living (IADL); 3) Comorbidity defined as >0 in the Charlson Comorbidity Index; and 4) Poor Self-Rated Health (SRH) defined as “very poor”, “poor” or “mediocre” in the SRH Questionnaire. Prevalence of individual and overlapping phenomena were examined. Results (see Figure) Mean age was 97.7 (± 2.3) years, ranging from 95 to 108 years, and 74.2% were female. In our sample, 20% of the centenarians were non-frail, 56% were pre-frail, and 24% were frail. Every frail centenarian had overlap with at least one of comorbidity, disability or poor SRH (or a combination of these). 11% of the centenarians had comorbidity only (no frailty, disability or poor SRH); 10% had disability only (no frailty, comorbidity or poor SRH); 7% had poor SRH only (no frailty, comorbidity or disability). 75% of centenarians with disability or poor SRH were not frail. Overall, 14% of the centenarians had all four phenomena (frailty, comorbidity, disability and poor SRH), whereas 9% were robust with none. Conclusions This is the first study to report the prevalence of overlap between frailty, comorbidity, disability and poor SRH amongst community-dwelling centenarians. Although frailty significantly overlaps with comorbidity, disability and poor SRH, almost one-in-ten centenarians were robust. Future studies should explore the complex interactions between frailty, comorbidity, disability and poor SRH amongst nature’s extreme survivors.