Allyson M. Kats

Effects of Mobility and Cognition on Risk of Mortality in Women in Late Life: A Prospective Study

BACKGROUND This study examines the effects of mobility and cognition on mortality risk in women late in life. METHODS A prospective study was conducted among 1,495 women (mean age 87.6 years) participating in the Study of Osteoporotic Fractures Year 20 examination (2006-2008). Mobility (ascertained by Short Physical Performance Battery [SPPB]) was categorized as poor (SPPB 0-3, n = 312), intermediate (SPPB 4-9, n = 799), or good (SPPB 10-12, n = 384). Cognitive status (adjudicated based on neuropsychological tests) was classified as normal (n = 873), mild cognitive impairment (n = 354), or dementia (n = 268). Deaths (n = 749) were identified from Year 20 through July 31, 2014 (average follow-up 4.9 years). RESULTS There was not strong evidence of an interaction between mobility and cognition for prediction of mortality risk (p interaction term .16). Compared to women with good mobility, mortality risks were increased among women with intermediate mobility (hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.02-1.57) and those with poor mobility (HR 1.64, 95% CI 1.24-2.16) after consideration of cognition and other mortality risk factors. Similarly, mortality risks were higher among women with mild cognitive impairment (HR 1.46, 95% CI 1.21-1.76) and those with dementia (HR 1.88, 95% CI 1.54-2.31) compared to women with normal cognition after consideration of mobility and other mortality risk factors. CONCLUSIONS Among women late in life, 5-year mortality risk was substantially increased among women with deficits in mobility even after accounting for cognition and traditional prognostic indicators. Similarly, deficits in cognition were associated with increased 5-year mortality despite consideration of mobility and conventional risk factors.

Effects of Mobility and Cognition on Hospitalization and Inpatient Days in Women in Late Life

Background: This study examines effects of mobility and cognition on hospitalization and inpatient days among women late in life. Methods: Prospective study of 663 women (mean age 87.7 years) participating in the Study of Osteoporotic Fractures Year 20 examination (2006–2008) linked with their inpatient claims data. At Year 20, mobility ascertained by Short Physical Performance Battery categorized as poor, intermediate, or good. Cognitive status adjudicated based on neuropsychological tests and classified as normal, mild cognitive impairment, or dementia. Hospitalizations (n = 182) during 12 months following Year 20. Results: Reduced mobility and poorer cognition were each associated in a graded manner with higher inpatient health care utilization, even after accounting for each other and traditional prognostic indicators. For example, adjusted mean inpatient days per year were 0.94 (95% confidence interval [CI] 0.52–1.45) among women with good mobility increasing to 2.80 (95% CI 1.64–3.89) among women with poor mobility and 1.59 (95% CI 1.08–2.03) among women with normal cognition increasing to 2.53 (95% CI 1.55–3.40) among women with dementia. Women with poor mobility/dementia had a nearly sixfold increase in mean inpatient days per year (4.83, 95% CI 2.73–8.54) compared with women with good mobility/normal cognition (0.84, 95% CI 0.49–1.44). Conclusions: Among women late in life, mobility limitations and cognitive deficits were each independent predictors of higher inpatient health care utilization even after considering each other and conventional predictors. Additive effects of reduced mobility and poorer cognition may be important to consider in medical decision making and health care policy planning for the growing population of adults aged ≥85 years.

Comparison of Associations of DXA and CT Visceral Adipose Tissue Measures With Insulin Resistance, Lipid Levels, and Inflammatory Markers

Visceral adipose tissue (VAT) measured by computed tomography (CT) is related to insulin resistance, lipids, and serum inflammatory markers. Our objective was to compare the strength of the associations of VAT measured using dual-energy X-ray absorptiometry (DXA-VAT) and CT (CT-VAT) with insulin resistance, serum lipids, and serum markers of inflammation. For 1117 men aged 65 and older enrolled in the Osteoporotic Fractures in Men Study, the cross-sectional associations of DXA-VAT and CT-VAT with homeostasis model assessment of insulin resistance (homa2ir), C-reactive protein, and high-density lipoprotein (HDL) cholesterol were estimated with regression models and compared using a Hausman test. Adjusted for age and body mass index, DXA-VAT was moderately associated with homa2ir (effect size 0.38, 95% confidence interval [CI]: 0.28-0.47) and modestly associated with HDL cholesterol (DXA effect size -0.29, 95% CI: -0.38 to -0.21). These associations were significantly greater than those for CT-VAT with homa2ir (0.30, 95% CI: 0.24-0.37; p value for effect size difference 0.03) and CT-VAT with HDL cholesterol (-0.22, 95% CI: -0.29 to -0.15; p value for difference 0.005). Neither DXA-VAT nor CT-VAT was associated with C-reactive protein after adjustment for age and body mass index (DXA-VAT effect size 0.14, 95% CI: -0.04 to 0.32; CT-VAT effect size 0.08, 95% CI: -0.08 to 0.25; p value for difference 0.35). DXA-VAT has similar or greater associations with insulin resistance and HDL cholesterol as does CT-VAT in older men, confirming the concurrent validity of DXA-VAT. Investigations of how well DXA measurements of VAT predict incident cardiovascular disease events are warranted.

Sleep disturbances and risk of hospitalization and inpatient days among older women

Study Objectives Determine the associations of sleep disturbances with hospitalization risk among older women. Methods One thousand eight hundred and twenty-seven women (mean age 83.6 years) participating in Study of Osteoporotic Fractures Year 16 (Y16) examination (2002-2004) linked with Medicare and/or HMO claims. At Y16 examination, sleep/wake parameters were measured by actigraphy (total sleep time [TST], sleep efficiency [SE], sleep latency [SL], and wake after sleep onset [WASO]) and subjective sleep measures (sleep quality [Pittsburgh Sleep Quality Index] and daytime sleepiness [Epworth Sleepiness Scale]) were assessed by questionnaire. Measures except TST were dichotomized based on clinical thresholds. Incident hospitalizations were determined from claims data. Results Nine hundred and seventy-six women (53%) had ≥1 hospitalization in the 3 years after the Year 16 examination. Reduced SE (odds ratio [OR] = 2.39, 95% confidence interval [CI] 1.69-3.39), prolonged SL (OR = 1.41, 95% CI 1.11-1.78), greater WASO (OR = 1.57, 95% CI 1.28-1.93), shorter TST (OR = 1.98, 95% CI 1.42-2.77) and poorer sleep quality (OR = 1.33, 95% CI 1.07-1.65) were each associated with a higher age and site-adjusted odds of hospitalization; associations were attenuated after multivariable adjustment for traditional prognostic factors with the OR for reduced SE (OR = 1.60, 95% CI 1.08-2.38) and shorter TST (OR = 1.63, 95% CI 1.12-2.37) remaining significant. Among women who were hospitalized, greater WASO (rate ratio [RR] = 1.20, 95% CI 1.04-1.37) and poorer sleep quality (RR = 1.18, 95% CI 1.02-1.35) were each associated with a greater age and site-adjusted RR of inpatient days, but associations did not persist after multivariate adjustment. Conclusions Older women with sleep disturbances have an increased risk of hospitalization partially attributable to demographics, poorer health status, and comorbidities.

Associations of recent weight loss with health care costs and utilization among older women

The association of weight loss with health care costs among older women is uncertain. Our study aim was to examine the association of objectively measured weight change with subsequent total health care (THC) costs and other health care utilization among older women. Our study population included 2,083 women (mean age 80.2 years) enrolled in the Study of Osteoporotic Fractures and U.S. Medicare Fee for Service. Weight loss and gain were defined, respectively, as ≥5% decrease and ≥5% increase in body weight, and weight maintenance as <5% change in body weight over a period of 4.5 years. THC costs, outpatient costs, hospitalizations, and skilled nursing facility [SNF] utilization were estimated from Medicare claims for 1 year after the period during which weight change was measured. The associations of weight change with THC and outpatient costs were estimated using generalized linear models with gamma variance and log link functions, and with hospitalizations and SNF utilization using logistic models. Adjusted for age and current body mass index (BMI), weight loss compared with weight maintenance was associated with a 35% increase in THC costs (

Frailty Phenotype and Healthcare Costs and Utilization in Older Women: Frailty, Utilization, and Costs

2148 [95% CI, 745 to 3552], 2014 U.S. dollars), a 15% increase in outpatient costs (

The Association Between Objectively Measured Physical Activity and Subsequent Health Care Utilization in Older Men

329 [95% C.I. −1 to 660]), and odds ratios of 1.42 (95% CI, 1.14 to 1.76) for ≥1 hospital stay and 1.45 (95% CI, 1.03 to 2.03) for ≥1 SNF stay. These associations did not vary by BMI category. After additional adjustment for multi-morbidity and functional status, associations of weight loss with all four outcomes were no longer significant. In conclusion, ≥5% weight loss among older women is not associated with increased THC and outpatient costs, hospitalization, and SNF utilization, irrespective of BMI category after accounting for multi-morbidity and impaired functional status that accompany weight loss.

Pre-fracture individual characteristics associated with high total health care costs after hip fracture.

To determine the association of the frailty phenotype with subsequent healthcare costs and utilization.

Predictors of change of trabecular bone score (TBS) in older men: results from the Osteoporotic Fractures in Men (MrOS) Study

BACKGROUND To examine the associations between objective physical activity measures and subsequent health care utilization. METHODS We studied 1,283 men (mean age 79.1 years, SD 5.3) participating in the Osteoporotic Fractures in Men Study. Participants wore a SenseWear® Pro Armband monitor for 1 week. Data was summarized as daily (i) step counts, (ii) total energy expenditure, (iii) active energy expenditure, and (iv) activity time (sedentary, ≥ light, ≥ moderate). The outcome measures of 1-year hospitalizations/duration of stay from Medicare data were analyzed with a two-part hurdle model. Covariates included age, clinical center, body mass index, marital status, depressive symptoms, medical conditions, cognitive function, and prior hospitalization. RESULTS Each 1 SD = 3,092 step increase in daily step count was associated with a 34% (95% confidence interval [CI]: 19%-46%) lower odds of hospitalization in base model (age and center) and 21% (95% CI: 4%-35%) lower odds of hospitalization in fully adjusted models. Similar but smaller associations held for other physical activity measures, but these associations were not significant in fully adjusted models. Among those hospitalized, higher step count was associated with shorter total duration of acute/postacute care stays in the base model only. There was a fourfold significant difference (from model-based estimates) in predicted care days comparing those with 2,000 versus 10,000 daily steps in the base model, but only a twofold difference (not significant) in the full model. CONCLUSION Daily step count is an easily determined measure of physical activity that may be useful in assessment of future health care burden in older men.