Cohort profile: the Taiwan Initiative for Geriatric Epidemiological Research - a prospective cohort study on cognition.

Objectives: The Taiwan Initiative for Geriatric Epidemiological Research (TIGER) was founded in 2011 to elucidate the interrelationships among various predictors of global and domain-specific cognitive impairment, with the aim of identifying older adults with an increased risk of dementia in the preclinical phase. Methods: TIGER, a population-based prospective cohort, recruited 605 older adults (aged 65 and above) at baseline (2011-2013). Participants have undergone structured questionnaires, global and domain-specific cognitive assessments, physical exams, and biological specimen collections at baseline and biennial follow-ups to date. Results: By 2022, TIGER has included 4 biennial follow-ups, with the participants comprising 53.9% women and having a mean age of 73.2 years at baseline. After an 8-year follow-up, the annual attrition rate was, reflecting a combination of 9.9% of participants who passed away and 36.2% who dropped out. TIGER has published novel and multidisciplinary research on cognitive-related outcomes in older adults, including environmental exposures (indoor and ambient air pollution), multimorbidity, sarcopenia, frailty, biomarkers (brain and retinal images, renal and inflammatory markers), and diet. Conclusion: TIGER's meticulous design, multidisciplinary data, and novel findings elucidate the complex etiology of cognitive impairment and frailty, offering valuable insights into factors that can be used to predict and prevent dementia in the preclinical phase.

Multimorbid Patterns and Cognitive Performance in the Presence of Informative Dropout Among Community-Dwelling Taiwanese Older Adults.

Background and Objectives: Longitudinal studies among older adults often feature elevated dropout rates and multiple chronic conditions. How Taiwanese multimorbid patterns relate to different cognitive domains remains unclear. This study aims to identify sex-specific multimorbid patterns and associate them with cognitive performance while modeling the risk for dropout. Research Design and Methods: A prospective cohort study (2011-19) in Taiwan recruited 449 Taiwanese older adults without dementia. Global and domain-specific cognition were assessed biennially. We used exploratory factor analysis to identify baseline sex-specific multimorbid patterns of 19 self-reported chronic conditions. We utilized a joint model incorporating longitudinal and time-to-dropout data to examine the association between multimorbid patterns and cognitive performance accounting for the informative dropout via the shared random effect. Results: At the end of the study, 324 participants (72.1%) remained in the cohort, with an average annual attrition rate of 5.5%. We found that advanced age, low levels of physical activities, and poor cognition at baseline were associated with increased dropout risks. Besides, 6 multimorbid patterns were identified, labeled Mental, Renal-vascular, and Cancer-urinary patterns in men, and Mental, Cardiometabolic, and Cancer-endocrine patterns in women. For men, as the follow-up time increased, the Mental pattern was associated with poor global cognition and attention; the Renal-vascular pattern was associated with poor executive function. For women, the Mental pattern was associated with poor memory; as follow-up time increased, and Cardiometabolic patterns were related to poor memory. Discussion and Implications: Sex-specific multimorbid patterns identified in the Taiwanese older population showed differences (notably Renal-vascular pattern in men) from patterns found in Western countries and were differentially associated with cognitive impairment over time. When informative dropout is suspected, appropriate statistical methods should be applied.

Effect of indoor air quality on the association of long-term exposure to low-level air pollutants with cognition in older adults.

BACKGROUND: How indoor air quality affects the temporal associations of long-term exposure to low-level air pollutants with cognition remains unclear. METHODS: This cohort study (2011-2019) included 517 non-demented older adults at baseline with four repeated cognitive assessments. The time-varying exposure to PM2.5, PM10, NO2, SO2, CO, and O3 was estimated for each participant from 1994 to 2019. Indoor air quality was determined by ventilation status and daily indoor time. Generalized linear mixed models were used to analyze the association of air pollutants, indoor air quality, and cognition adjusting for important covariates. RESULTS: Over time, per 2.97 µg/m3 (i.e., an interquartile range) increment of PM2.5 was associated with the poor performance of memory (Z score of a cognitive test, ߈:-0.14), attention (߈:-0.13), and executive function (߈:-0.20). Similarly, per 2.05 µg/m3 increase in PM2.5-10 was associated with poor global cognition [adjusted odds ratio (aOR): 1.48, ߈:-0.28], attention (߈:-0.07), and verbal fluency (߈:-0.09); per 4.94 µg/m3 increase in PM10 was associated with poor global cognition (aOR: 1.78; ߈:-0.37). In contrast, per 2.74 ppb increase in O3 was associated with better global cognition (߈:0.36 to 0.47). These associations became more evident in participants with poor ventilation or short daily indoor time (<12.5 h/day). For global cognition, the exposure to a 10-µg/m3 increment in PM2.5, PM2.5-10, and PM10 corresponded to 1.4, 5.8, and 2.8 years of aging, respectively. CONCLUSION: This study demonstrated how indoor air quality in areas using clean fuels differentially affected the associations of long-term exposure to low-level air pollutants with cognition. Tightening air quality standards may help prevent dementia.

Integrated approach for multimorbid patients in a hospitalist setting: Survival analysis of a two-year prospective study.

BACKGROUND/PURPOSE: Multimorbidity is a worldwide issue when aging is rapidly. The aim of this study was to evaluate the impact of demography, morbidity, disability and depression on short-term and long-term mortality for multimorbid inpatients. METHODS: The participants' information were assessed upon recruitment. Multimorbidity and disability were measured by modified Charlson comorbidities Index (CCI) and Barthel Index for Activity of Daily Living (ADL), respectively. Depression was screened over one-item self-reported perceptions of depressed mood rated as yes or no. The factors of in-hospital mortality and periodic mortality after discharge were examined by Cox proportional hazard regression and Kaplan-Meier survival analyses. RESULTS: A total of 201 inpatients from a hospitalist's ward were recruited. The in-hospital mortality was 14.4%, while 24-month mortality was 57.8%. After adjustment, severe ADL dependence (<35) was the only contributing factor for in-hospital mortality (Hazard Ratio [HR] = 12.94, p = 0.018). The hazard ratios of 3-6-12-24-months of high CCI (≥6) and severe ADL dependence were 8.12-13.57 (p < 0.001) and 2.91-5.39 (p < 0.001) respectively; both trends of impacts were decreasing overtime. Gender rather than age effect was evident. Besides, self-reported depression was associated with 12-month (HR = 1.72, p = 0.04) and 24-month (HR = 1.65, p = 0.038) mortality. Moreover, severe ADL dependence (p = 0.001) and depression (p = 0.01) contributed to higher mortality in non-cancer patients. CONCLUSION: Our findings suggested that gender, multimorbidity, and disability influenced the two-year survival, while depression was the strongest factor related to long-term mortality. Clinicians should notice the importance of integrated approach and mental health care for those with severe disabilities and morbidity.