Cross-national health comparisons using the Rasch model: findings from the 2012 US Health and Retirement Study and the 2012 Mexican Health and Aging Study

Dysphagia and Functional Limitations Among Adults in the United States: Findings from the 2022 National Health Interview Survey

Dysphagia or swallowing dysfunction is associated with reduced quality of life and poor long term outcomes. While standard dysphagia treatment focuses on improving swallowing function, it is not clear if people with dysphagia also have difficulties performing daily tasks. This study aimed to determine if individuals with dysphagia had difficulties with participating in daily tasks requiring physical function, as compared to those with no dysphagia. We conducted a secondary data analysis using the responses of 24,107 adults aged 18 years or older who completed the 2022 National Health Interview Survey. The independent variable was report of swallowing problem during the past 12 months, and the dependent variables were report of difficulty in physical function tasks (e.g., self-care, mobility, working, social participation). We utilized propensity score methods to balance demographic and clinical variables between groups, and examined if individuals with dysphagia had more difficulties with the physical function tasks. The propensity score methods balanced the demographic and clinical variables (absolute standardized differences < 0.1). People with dysphagia had significantly higher odds ratios (ranged from 1.23 to 1.70, all p < 0.05) of having difficulties in physical function tasks than those without dysphagia. The findings revealed an association between experiencing dysphagia and encountering difficulties in self-care, mobility, working, and social participation in the general adult population in the US. Results of our study indicate that during the course of rehabilitation, healthcare professionals should consider the potential impact of dysphagia symptoms on clients' ability to partake in independent activities in their community settings.

Harmonisation of later-life cognitive function across national contexts: results from the Harmonized Cognitive Assessment Protocols

BACKGROUND

The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonise general and domain-specific cognitive scores from HCAP studies across six countries, and evaluate reliability and criterion validity of the resulting harmonised scores.

METHODS

We statistically harmonised general and domain-specific cognitive function scores across publicly available HCAP partner studies in China, England, India, Mexico, South Africa, and the USA conducted between October, 2015 and January, 2020. Participants missing all cognitive test items in a given HCAP were excluded. We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies. We generated harmonised factor scores to represent a person's relative functioning on the latent factors of general cognitive function, memory, executive function, orientation, and language using confirmatory factor analysis. We evaluated the marginal reliability, or precision, of the factor scores using test information plots. Criterion validity of factor scores was assessed by regressing the scores on age, gender, and educational attainment in a multivariable analysis adjusted for these characteristics.

FINDINGS

We included 21 144 participants from the six HCAP studies of interest (11 480 women [54·3%] and 9664 [45·7%] men), with a median age of 69 years (IQR 64-76). Confirmatory factor analysis models of cognitive function in each country fit well: 31 (88·6%) of 35 models had adequate or good fit to the data (comparative fit index ≥0·90, root mean square error of approximation ≤0·08, and standardised root mean residual ≤0·08). Marginal reliability of the harmonised general cognitive function factor was high (>0·9) for 19 044 (90·1%) of 21 144 participant scores across the six countries. Marginal reliability of the harmonised factor was above 0·85 for 19 281 (91·2%) of 21 142 participant factor scores for memory, 7805 (41·0%) of 19 015 scores for executive function, 3446 (16·3%) of 21 103 scores for orientation, and 4329 (20·5%) of 21 113 scores for language. In each country, general cognitive function scores were lower with older age and higher with greater levels of educational attainment.

INTERPRETATION

We statistically harmonised cognitive function measures across six large population-based studies of cognitive ageing. These harmonised cognitive function scores empirically reflect comparable domains of cognitive function among older adults across the six countries, have high reliability, and are useful for population-based research. This work provides a foundation for international networks of researchers to make improved inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes in pooled analyses.

FUNDING

US National Institute on Aging.

Harmonization of Later-Life Cognitive Function Across National Contexts: Results from the Harmonized Cognitive Assessment Protocols (HCAPs)

Background

The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonize general and domain-specific cognitive scores from HCAPs across six countries, and evaluate precision and criterion validity of the resulting harmonized scores.

Methods

We statistically harmonized general and domain-specific cognitive function across the six publicly available HCAP partner studies in the United States, England, India, Mexico, China, and South Africa (N=21,141). We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies, as identified by a multidisciplinary expert panel. We generated harmonized factor scores for general and domain- specific cognitive function using serially estimated graded-response item response theory (IRT) models. We evaluated precision of the factor scores using test information plots and criterion validity using age, gender, and educational attainment.

Findings

IRT models of cognitive function in each country fit well. We compared measurement reliability of the harmonized general cognitive function factor across each cohort using test information plots; marginal reliability was high (r> 0·90) for 93% of respondents across six countries. In each country, general cognitive function scores were lower with older ages and higher with greater levels of educational attainment.

Interpretation

We statistically harmonized cognitive function measures across six large, population-based studies of cognitive aging in the US, England, India, Mexico, China, and South Africa. Precision of the estimated scores was excellent. This work provides a foundation for international networks of researchers to make stronger inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes.

Funding

National Institute on Aging (R01 AG070953, R01 AG030153, R01 AG051125, U01 AG058499; U24 AG065182; R01AG051158).

Developing a Cross-National Disability Measure for Older Adult Populations across Korea, China, and Japan

This study aims to develop a universal scale for comparing cognitive and physical functions among countries using health survey data from China, Korea, and Japan. This study used the data of 934 participants from the Korean Longitude Study of Aging, 2506 participants from the China Health and Retirement Longitude Study, and 178 participants from the Japanese Study of Aging and Retirement. Each physical and cognitive function item in the three countries has five key items. The anchoring method used the key items to link each cognitive and physical function of the three countries. We investigated the psychometric characteristics of the final item using the Rasch analysis. We extracted 13 items of 19 cognitive function items and 20 items out of 29 physical function items using the anchoring method and the Rasch analysis. The Rasch analysis showed good fit statistics for 13 cognitive function items and 20 physical function items. The measurement scale developed in this study will enable valid comparisons of older adults' cognitive and physical functions across these three countries.

Development of a physical function outcome measure to harmonize comparisons between three Asian adult populations

PURPOSE

The purpose of this study was to use modern measurement techniques and create a precise functional status metric for Asian adults.

METHODS

The study subjects included Asian American adults from the 2012 Health and Retirement Study (n = 211), Chinese adults in the China Health and Retirement Longitudinal Study (n = 13,649), and Korean adults in the Korean Longitudinal Study of Aging (n = 7,486). The Rasch common-item equating method with nine self-care and mobility items from the three databases were used to create a physical function measure across the three Asian adult populations.

RESULTS

The created physical function measure included 23 self-care and mobility tasks and demonstrated acceptable psychometric properties (unidimensional, local independence, no misfit, no differential item functioning). A significant group difference in the estimated physical function across the three Asian adult populations ([Formula: see text] = 445.21, p < 0.0001) was identified. The American Asian adults (5.16 logits) had better physical function compared to the Chinese (4.15 logits) and Korean adults (3.32 logits).

CONCLUSION

Since the outcome measure was calibrated with the population-representative Asian samples, this derived physical function measure can be used for cross-national comparisons between the three countries. Using this precise functional status metric can help to identify factors that influence health outcomes in other Asian countries (China and Korea). This has the potential to generate numerous benefits, such as international disability monitoring and health-related policy development, improved shared decision making, and international syntheses of research findings.

Cardiovascular disease risk prediction for people with type 2 diabetes in a population-based cohort and in electronic health record data

Objective

Electronic health records (EHRs) have become a common data source for clinical risk prediction, offering large sample sizes and frequently sampled metrics. There may be notable differences between hospital-based EHR and traditional cohort samples: EHR data often are not population-representative random samples, even for particular diseases, as they tend to be sicker with higher healthcare utilization, while cohort studies often sample healthier subjects who typically are more likely to participate. We investigate heterogeneities between EHR- and cohort-based inferences including incidence rates, risk factor identifications/quantifications, and absolute risks.

Materials and methods

This is a retrospective cohort study of older patients with type 2 diabetes using EHR from New York University Langone Health ambulatory care (NYULH-EHR, years 2009–2017) and from the Health and Retirement Survey (HRS, 1995–2014) to study subsequent cardiovascular disease (CVD) risks. We used the same eligibility criteria, outcome definitions, and demographic covariates/biomarkers in both datasets. We compared subsequent CVD incidence rates, hazard ratios (HRs) of risk factors, and discrimination/calibration performances of CVD risk scores.

Results

The estimated subsequent total CVD incidence rate was 37.5 and 90.6 per 1000 person-years since T2DM onset in HRS and NYULH-EHR respectively. HR estimates were comparable between the datasets for most demographic covariates/biomarkers. Common CVD risk scores underestimated observed total CVD risks in NYULH-EHR.

Discussion and conclusion

EHR-estimated HRs of demographic and major clinical risk factors for CVD were mostly consistent with the estimates from a national cohort, despite high incidences and absolute risks of total CVD outcome in the EHR samples.

Associations between physical health conditions and posttraumatic stress disorder according to age

OBJECTIVES

Posttraumatic stress disorder (PTSD) is associated with various physical health conditions. However, it is unclear whether the relationship between PTSD and physical health conditions differs according to age. This study aims to examine the associations between PTSD and physical health conditions across four adult age categories.

METHODS

We analyzed data from the 2012 to 2013 National Epidemiologic Survey on Alcohol and Related Conditions (N = 36,309). The Alcohol Use Disorder and Associated Disabilities Interview Schedule-5 assessed past-year DSM-5 PTSD. Multiple regression analyses examined associations between PTSD (reference = no PTSD) with number and type of physical health conditions in each age category (18-34: "younger adults," 35-49: "middle-aged adults," 50-64: "young-old adults," 65+: "older adults").

RESULTS

The prevalence of nearly all physical health conditions increased according to age, whereas the prevalence of PTSD tended to decrease with age. After adjustment, PTSD was associated with a greater number of physical health conditions among all age categories (b range: 0.62-1.29). Regardless of age category, PTSD was associated with increased odds of cardiovascular and musculoskeletal conditions (AOR range: 1.54-2.34). PTSD was also associated with increased odds of gastrointestinal, hepatobiliary, endocrine/metabolic, respiratory, neurologic conditions, cancer, sleep disorders, and anemia among select age categories (AOR range: 1.70-3.31). For most physical health conditions, the largest effect sizes emerged for younger and middle-aged adults.

CONCLUSIONS

PTSD is associated with many physical health conditions across the age spectrum, particularly among younger and middle-aged adults. Results may inform targeted screening and intervention strategies to mitigate risk of physical health conditions among adults with PTSD.

Comparisons of the Association of Family and Social Factors With Functional Limitations Across the United States, Mexico, and South Korea: Findings From the HRS Family of Surveys

Objective: The association of family and social factors with the level of functional limitations was examined across the United States, Mexico, and Korea. Method: Participants included adults from the 2012 Health and Retirement Study (n = 10,017), Mexican Health and Aging Study (n = 6,367), and Korean Longitudinal Study of Aging (n = 4,134). A common functional limitation scale was created based on Rasch analysis with a higher score indicating better physical function. Results: The American older adults (3.65 logits) had better physical function compared with Mexican (2.81 logits) and Korean older adults (1.92 logits). There were different associations of family and social factors with functional limitations across the three countries. Discussion: The American older adults demonstrated less functional limitation compared with Mexican and Korean older adults at the population level. The findings indicate the need to interpret carefully the individual family and social factors associated with functional limitations within the unique context of each country.