Heart Rate Variability and Incident Stroke

BACKGROUND AND PURPOSE: Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort. METHODS: The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus. RESULTS: Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus. CONCLUSIONS: Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus

Cost effectiveness of a cultural physical activity intervention to reduce blood pressure among Native Hawaiians with hypertension

Objective: The aim of this study was to calculate the costs and assess whether a culturally grounded physical activity intervention offered through community-based organizations is cost effective in reducing blood pressure among Native Hawaiian adults with hypertension. Methods: Six community-based organizations in Hawai'i completed a randomized controlled trial between 2015 and 2019. Overall, 263 Native Hawaiian adults with uncontrolled hypertension (≥ 140 mmHg systolic, ≥ 90 mmHg diastolic) were randomized to either a 12-month intervention group of hula (traditional Hawaiian dance) lessons and self-regulation classes, or to an education-only waitlist control group. The primary outcome was change in systolic blood pressure collected at baseline and 3, 6, and 12 months for the intervention compared with the control group. Incremental cost-effectiveness ratios (ICERs) were calculated for primary and secondary outcomes. Non-parametric bootstrapping and sensitivity analyses evaluated uncertainty in parameters and outcomes. Results: The mean intervention cost was US$361/person, and the 6-month ICER was US$103/mmHg reduction in systolic blood pressure and US$95/mmHg in diastolic blood pressure. At 12 months, the intervention group maintained reductions in blood pressure, which exceeded reductions for usual care based on blood pressure outcomes. The change in blood pressure at 12 months resulted in ICERs of US$100/mmHg reduction in systolic blood pressure and US$93/mmHg in diastolic blood pressure. Sensitivity analyses suggested that at the estimated intervention cost, the probability that the program would lower systolic blood pressure by 5 mmHg was 67 and 2.5% at 6 and 12 months, respectively. Conclusion: The 6-month Ola Hou program may be cost effective for low-resource community-based organizations. Maintenance of blood pressure reductions at 6 and 12 months in the intervention group contributed to potential cost effectiveness. Future studies should further evaluate the cost effectiveness of indigenous physical activity programs in similar settings and by modeling lifetime costs and quality-adjusted life-years. Trial registration number: NCT02620709.Sociolog

The Impact of Patient and Provider Factors on Depression Screening of American Indian and Alaska Native People in Primary Care

Introduction : The US Preventive Services Task Force recommends routine depression screening in primary care, yet regular screening does not occur in most health systems serving Alaska Native and American Indian people. The authors examined factors associated with administration of depression screening among Alaska Native and American Indian people in a large urban clinic. Methods : Medical records of 18 625 Alaska Native and American Indian adults were examined 1 year after implementation of a depression screening initiative. Multilevel logistic regression models examined associations between patient and provider factors and administration of the Patient Health Questionnaire–9. Results : Forty-seven percent of patients were screened. Women were more likely than men to be screened (50% vs 43%, P < .001). Increased screening odds were associated with older age, increased service use, and chronic disease ( P < .001) but not with substance abuse disorders or prior antidepressant dispensation. Women previously diagnosed with depression had higher odds of screening ( P = .002). Men seen by male providers had higher odds of screening than did men seen by female providers ( P = .040). Screening rates peaked among providers with 2 to 5 years of employment with the clinic. Limitations : Cross-sectional analysis of medical record data was of unknown reliability; there were limited sociodemographic data. Conclusions : Even with significant organizational support for annual depression screening, primary care providers systematically missed men and patients with infrequent primary care visits. Outreach to male patients and additional supports for primary care providers, especially in the first years of practice, may improve screening and treatment for depression among Alaska Native and American Indian people

Patterns of Healthcare Use and Mortality After Alzheimer's Disease or Related Dementia Diagnosis Among Alaska Native Patients: Results of a Cluster Analysis in a Tribal Healthcare Setting

Background: Alaska Native and American Indian (AN/AI) people represent a rapidly aging population with disproportionate burdens of Alzheimer's disease and related dementias (ADRD) risk factors. Objective: To characterize healthcare service use patterns and mortality in the years following ADRD diagnosis for patients in an Alaska Native Tribal health system. Methods: The study sample included all AN/AI patients aged 55 or older with an ADRD diagnosis who were seen between 2012-2018 (n = 407). We used cluster analysis to identify distinct patterns of healthcare use for primary care, emergency and urgent care, inpatient hospital stays, and selected specialty care. We compared demographic and clinical factors between clusters and used regression to compare mortality. Results: We identified five clusters of healthcare service use patterns after ADRD diagnosis: 1) people who use a low amount of all services (n = 107), 2) people who use a high amount of all services (n = 60), 3) people who use a high amount of primary and specialty care (n = 105), 4) people who use a high amount of specialty care (n = 65), and 5) people who use a high amount of emergency and urgent care (n = 70). The cluster with the highest use had the greatest proportion of comorbidities and had a 2.3-fold increased risk of mortality compared to the cluster with the lowest healthcare service use. Conclusion: Results indicate that those receiving the most services had the greatest healthcare-related needs and increased mortality. Future research could isolate factors that predict service use following ADRD diagnosis and identify other differential health risks

Heart Rate Variability and Incident Stroke

BACKGROUND AND PURPOSE: Low heart rate variability (HRV), a marker of cardiac autonomic dysfunction, has been associated with increased all-cause and cardiovascular mortality. We examined the association between reduced HRV and incident stroke in a community-based cohort. METHODS: The Atherosclerosis Risk in Communities (ARIC) study measured HRV using 2-minute ECG readings in 12 550 middle-aged adults at baseline (1987-1989). HRV indices were calculated using the SD of RR intervals (SDNN), the mean of all normal RR intervals (meanNN), the root mean square of successive differences of successive RR intervals (RMSSD), low (LF) and high (HF) frequency power, and the LF/HF ratio. All HRV measures were categorized into quintiles. Incident stroke was adjudicated through 2011. Cox regression was used to estimate hazard ratios (HRs) with the lowest HRV quintile as the reference, with and without stratification by prevalent diabetes mellitus. RESULTS: Over a median follow-up of 22 years, 816 (6.5%) participants experienced incident stroke. After covariate adjustment, there was no strong evidence of association between HRV and stroke risk. In stratified analyses, the lowest HRV quintile was associated with higher stroke risk compared with the highest quintile for SDNN (HR, 2.0, 95% confidence interval, 1.1-4.0), RMSSD (HR, 1.7; 95% confidence interval, 0.9-3.2), LF (HR, 1.5; 95% confidence interval, 0.8-3.0), and HF (HR, 1.7; 95% confidence interval, 0.9-3.0) only among people with diabetes mellitus. CONCLUSIONS: Lower HRV was associated with higher risk of incident stroke among middle-aged adults with prevalent diabetes mellitus but not among people without diabetes mellitus