Assessment of Chronic Hypercapnic Respiratory Failure.

Undiagnosed chronic hypercapnic respiratory failure may be encountered during the evaluation of sleep-related breathing disorders at the sleep clinic. This article reviews the mechanism of chronic hypercapnic respiratory failure and the systematic approach to the assessment of specific sleep disorders associated with nocturnal hypoventilation encountered in clinical practice.

The History and Applications of the Veterans RAND 12-Item Health Survey (VR-12).

There has been an increasing emphasis on placing patients at the center of clinical care and health care research and, in particular, assessing outcomes and experiences from the patient's perspective. One of the most widely used patient-reported outcome instruments is the Veterans RAND 12-item Health Survey (VR-12). This article reviews the VR-12 development and its applications over the last 2 decades, including research and potential uses in clinical care.

Health Status in Adults With Chronic Conditions: Intervention Strategies for Improving Patient-Reported Outcomes.

This literature review analyzes 418 articles from 2 periods (2000-2010 and 2011-2017) to provide interpretative guidelines for the change in physical (PCS) and mental component summaries (MCS) of well-established patient-reported measures (MOS SF-36 V1, HOS SF-12, VR-36, and VR-12). The magnitude of the intervention effects was calculated using baseline and follow-up data. Results were similar across the 2 periods, although the effects of social and behavioral interventions are less consistent and are smaller for PCS. Both single interventions and multicomponent interventions met the moderate to large effect size criterion for PCS and MCS.

A new algorithm to build bridges between two patient-reported health outcome instruments: the MOS SF-36® and the VR-12 Health Survey.

PURPOSE: To develop bridging algorithms to score the Veterans Rand-12 (VR-12) scales for comparability to those of the SF-36® for facilitating multi-cohort studies using data from the National Cancer Institute Surveillance, Epidemiology, and End Results Program (SEER) linked to Medicare Health Outcomes Survey (MHOS), and to provide a model for minimizing non-statistical error in pooled analyses stemming from changes to survey instruments over time. METHODS: Observational study of MHOS cohorts 1-12 (1998-2011). We modeled 2-year follow-up SF-36 scale scores from cohorts 1-6 based on baseline SF-36 scores, age, and gender, yielding 100 clusters using Classification and Regression Trees. Within each cluster, we averaged follow-up SF-36 scores. Using the same cluster specifications, expected follow-up SF-36 scores, based on cohorts 1-6, were computed for cohorts 7-8 (where the VR-12 was the follow-up survey). We created a new criterion validity measure, termed "extensibility," calculated from the square root of the mean square difference between expected SF-36 scale averages and observed VR-12 item score from cohorts 7-8, weighted by cluster size. VR-12 items were rescored to minimize this quantity. RESULTS: Extensibility of rescored VR-12 items and scales was considerably improved from the "simple" scoring method for comparability to the SF-36 scales. CONCLUSIONS: The algorithms are appropriate across a wide range of potential subsamples within the MHOS and provide robust application for future studies that span the SF-36 and VR-12 eras. It is possible that these surveys in a different setting outside the MHOS, especially in younger age groups, could produce somewhat different results.

Guideline-recommended medications: variation across Medicare Advantage plans and associated mortality.

OBJECTIVES: To evaluate variation in the prescription of guideline-recommended medications across Medicare Advantage (MA) plans and to determine whether such variation is associated with increased mortality. METHODS: Observational study of 111,667 patients aged 65 years or older receiving care in 203 MA plans. We linked data from the Medicare Health Outcomes (HOS) Survey cohort 9 (April 2006-May 2008) with the Medicare Part D prescription benefit files (January 1, 2006-December 31, 2007) to examine variation in treatment across MA plans and its association with differences in observed (O)/expected (E) mortality ratio for 5 high-volume chronic conditions: diabetes, coronary artery disease (CAD), congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD)/asthma, and depression. RESULTS: Analysis of variance confirmed that the 203 MA plans differed significantly in their use of guideline-recommended treatment (P≤0.02). Those MA plans with higher use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (r=-0.40; P<0.0001) and beta-blockers (r=-0.27; P<0.0001) in patients with CHF were significantly associated with lower O/E mortality ratios. Those MA plans with higher use of multiple guideline-recommended medications were significantly associated with lower O/E mortality ratios in CHF (r=-0.45; P<0.0001) and diabetes (r=-0.14; P<0.042). There were no significant associations between the variation in performance indicators and mortality ratios in patients with CAD and COPD/asthma. Those MA plans with higher use of antidepressant medications had significantly higher O/E mortality ratios (r=0.28, P<0.0001). CONCLUSIONS: There was wide variation across MA plans in the prescription of guideline-recommended medications that had a measurable relationship to the mortality of elderly patients with CHF and diabetes. These findings can serve to both motivate and target quality improvement programs.

Estimating utilities for chronic kidney disease, using SF-36 and SF-12-based measures: challenges in a population of veterans with diabetes.

PURPOSE: Using transformations of existing quality-of-life data to estimate utilities has the potential to efficiently provide investigators with utility information. We used within-method and across-method comparisons and estimated disutilities associated with increasing chronic kidney disease (CKD) severity. METHODS: In an observational cohort of veterans with diabetes (DM) and pre-existing SF-36/SF-12 responses, we used six transformation methods (SF-12 to EQ-5D, SF-36 to HUI2, SF-12 to SF-6D, SF-36 to SF-6D, SF-36 to SF-6D (Bayesian method), and SF-12 to VR-6D) to estimate unadjusted utilities. CKD severity was staged using glomerular filtration rate estimated from serum creatinines, with the modification of diet in renal disease formula. We then used multivariate regression to estimate disutilities specifically associated with CKD severity stage. RESULTS: Of 67,963 patients, 22,273 patients had recent-onset DM and 45,690 patients had prevalent DM. For the recent-onset group, the adjusted disutility associated with CKD derived from the six transformation methods ranged from 0.0029 to 0.0045 for stage 2; -0.004 to -0.0009 for early stage 3; -0.017 to -0.010 for late stage 3; -0.023 to -0.012 for stage 4; -0.078 to -0.033 for stage 5; and -0.012 to -0.001 for ESRD/dialysis. CONCLUSION: Disutility did not increase monotonically as CKD severity increased. Differences in disutilities estimated using the six different methods were found. Both findings have implications for using such estimates in economic analyses.

Monitoring outcomes for the Medicare Advantage program: methods and application of the VR-12 for evaluation of plans.

The Veterans RAND 12-Item Health Survey (VR-12) is one of the major patient-reported outcomes for ranking the Medicare Advantage (MA) plans in the Health Outcomes Survey (HOS). Approaches for scoring physical and mental health are given using contemporary norms and regression estimators. A new metric approach for the VR-12 called the "VR-6D" is presented with case-mix adjustments for monitoring plans that combine utilities and mortality. Results show that the models for ranking health outcomes of the plans are robust and credible. Future directions include the use of utilities for evaluating and ranking of MA plans.

A preference-based measure of health: the VR-6D derived from the veterans RAND 12-Item Health Survey.

PURPOSE: The Veterans RAND 12-Item Health Survey (VR-12) is currently the major endpoint used in the Medicare managed care outcomes measure in the Healthcare Effectiveness Data and Information Set (HEDIS(®)), referred to as the Health Outcomes Survey (HOS). The purpose of this study is to adapt the Brazier SF-6D utility measure to the VR-12 to generate a single utility index. METHODS: We used the HOS cohorts 2 and 3 for SF-36 data and 9 for VR-12 data. We calculated SF-6D scores from the SF-36 using the algorithms developed by Brazier and colleagues. The values of the Brazier SF-6D were used to estimate utility scores from the VR-12 using a mapping approach based on a 2-stage mapping procedure, named as VR-6D. RESULTS: The VR-6D derived from the VR-12 has similar distributional properties as the SF-6D. The change in VR-6D showed significant variations across disease groups with different levels of morbidity and mortality. CONCLUSIONS: This study produced a utility measure for the VR-12 that is comparable to the SF-6D and responsive to change. The VR-6D can be used in evaluations of health care plans and cost-effectiveness analysis to compare the health gains that health care interventions can achieve.

Deriving SF-12v2 physical and mental health summary scores: a comparison of different scoring algorithms.

PURPOSE: Summary scores for the SF-12, version 2 (SF-12v2) health status measure are based on scoring coefficients derived for version 1 of the SF-36, despite changes in item wording and response scales and despite the fact that SF-12 scales only contain a subset of SF-36 items. This study derives new summary scores based directly on SF-12v2 data from a recent U.S. sample and compares the new summary scores to the standard ones. Due to controversy regarding methods for developing scoring coefficients for the summary score, we compare summary scores produced by different methods. METHODS: We analyzed nationally representative U.S. data, which provided 53,399 observations for the SF-12v2 in 2003-2005. In addition to the standard SF-12V2 scoring algorithm, summary scores were generated using exploratory factor analysis (EFA), principal components analysis (PCA), and confirmatory factor analysis (CFA), with orthogonal and oblique rotation. We examined correlations among different summary scores, their associations with demographic and clinical variables, and the consistency between changes in scale scores and in summary scores over time. RESULTS: The 8 scale means in the current data were similar to the 1998 SF-12v2 means, with the exception of the vitality scale. Correlations among the scales based on SF-12v2 data differed slightly from correlations derived from scales based on the SF-36 data. Correlations among summary scores derived using different methods were high (≥0.84). However, changes in summary scores derived using orthogonal rotation of components or factors were not consistent with changes in sub-scales, whereas changes in summary scores derived using oblique rotation were more consistent with patterns of change in sub-scales. CONCLUSIONS: Although the basic structure of the SF-12 is stable, summary scores derived from oblique rotation are preferable and more consistent with changes in individual scales. On empirical and conceptual grounds, we suggest using summary scores based on oblique CFA.

Comparison of health outcomes for male seniors in the Veterans Health Administration and Medicare Advantage plans.

OBJECTIVES: To compare the Veterans Health Administration (VHA) with the Medicare Advantage (MA) plans with regard to health outcomes. DATA SOURCES: The Medicare Health Outcome Survey, the 1999 Large Health Survey of Veteran Enrollees, and the Ambulatory Care Survey of Healthcare Experiences of Patients (Fiscal Years 2002 and 2003). STUDY DESIGN: A retrospective study. EXTRACTION METHODS: Men 65+ receiving care in MA (N=198,421) or in VHA (N=360,316). We compared the risk-adjusted probability of being alive with the same or better physical (PCS) and mental (MCS) health at 2-years follow-up. We computed hazard ratio (HR) for 2-year mortality. PRINCIPAL FINDINGS: Veterans had a higher adjusted probability of being alive with the same or better PCS compared with MA participants (VHA 69.2 versus MA 63.6 percent, p<.001). VHA patients had a higher adjusted probability than MA patients of being alive with the same or better MCS (76.1 versus 69.6 percent, p<.001). The HRs for mortality in the MA were higher than in the VHA (HR, 1.26 [95 percent CI 1.23-1.29]). CONCLUSIONS: Our findings indicate that the VHA has better patient outcomes than the private managed care plans in Medicare. The VHA's performance offers encouragement that the public sector can both finance and provide exemplary health care.

Differences in risk-adjusted mortality between medicaid-eligible patients enrolled in medicare advantage plans and those enrolled in the veterans health administration.

BACKGROUND: We compared risk-adjusted mortality rates between Medicaid-eligible patients in the Medicare Advantage plans ("MA dual enrollees") and Medicaid-eligible patients in the Veterans Health Administration ("VHA dual enrollees"). METHODS: We used the Death Master File to ascertain the vital status of 1912 MA and 2361 VHA dual enrollees. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: The 3-year mortality rates of VHA and MA dual enrollees were 15.8% and 19.0%, respectively. The adjusted HR of mortality in the MA dual enrollees was significantly higher than in the VHA dual enrollees (HR, 1.260 [95% CI, 1.044-1.520]). This was also the case for elderly patients and those from racial/ethnic minority groups. CONCLUSIONS: The VHA had better health outcomes than did MA plans. The VHA's performance is reassuring, given its emphasis on equal access to healthcare in an environment that is less dependent on patient financial considerations.

Updated U.S. population standard for the Veterans RAND 12-item Health Survey (VR-12).

PURPOSE: The purpose of this project was to develop an updated U.S. population standard for the Veterans RAND 12-item Health Survey (VR-12). METHODS: We used a well-defined and nationally representative sample of the U.S. population from 52,425 responses to the Medical Expenditure Panel Survey (MEPS) collected between 2000 and 2002. We applied modified regression estimates to update the non-proprietary 1990 scoring algorithms. We applied the updated standard to the Medicare Health Outcomes Survey (HOS) to compute the VR-12 physical (PCS((MEPS standard))) and mental (MCS((MEPS standard))) component summaries based on the MEPS. We compared these scores to PCS and MCS based on the 1990 U.S. population standard. RESULTS: Using the updated U.S. population standard, the average VR-12 PCS((MEPS standard)) and MCS((MEPS standard)) scores in the Medicare HOS were 39.82 (standard deviation [SD] = 12.2) and 50.08 (SD = 11.4), respectively. For the same Medicare HOS, the average PCS and MCS scores based on the 1990 standard were 1.40 points higher and 0.99 points lower in comparison to VR-12 PCS and MCS, respectively. CONCLUSIONS: Changes in the U.S. population between 1990 and today make the old standard obsolete for the VR-12, so the updated standard developed here is widely available to serve as such a contemporary standard for future applications for health-related quality of life (HRQoL) assessments.

Change in health status and mortality as indicators of outcomes: comparison between the Medicare Advantage Program and the Veterans Health Administration.

BACKGROUND: Comparing health outcomes with adequate methodology is central to performance assessments of health care systems. We compared the Medicare Advantage Program (MAP) and the Veterans Health Administration (VHA) with regard to changes in health status and mortality. METHODS: We used the Death-Master-File for vital status and the Short-Form 36 to determine physical (PCS) and mental (MCS) health at baseline and at 2 years. We compared the probability of being alive with the same or better (than would be expected by chance) PCS (or MCS) at 2 years and mortality, while adjusting for case-mix. Given the geographic variations in MAP enrollment, we did a regional sub-analysis. RESULTS: There were no significant differences in the probability of being alive with the same or better PCS except for the South (VHA 65.8% vs. MAP 62.5%, P = .0014). VHA patients had a slightly higher probability than MAP patients of being alive with the same or better MCS (71.8% vs. 70.1%, P = .002) but no significant regional variations. The hazard ratios for mortality in the MAP were higher than in the VHA across all regions. CONCLUSION: With the use of appropriate methodology, we found small differences in 2-year health outcomes that favor the VHA.

A Patient-based severity measure of chronic lung disease: evaluating functional health and predicting health services use.

Prior research has consistently shown that among patients with chronic lung disease (CLD), health-related quality of life (HRQOL) is tied more to respiratory symptoms than to physiologic measures. However, traditional methods to quantify the severity of CLD have been restricted to physiologic measures (eg, FEV1, FVC, etc) that are often poor predictors of HRQOL and utilization of health services. Using a patient-based measure of symptom severity for CLD developed in the Veterans Health Study (VHS), this article evaluated the impact of the severity of CLD on patients' self-reported HRQOL and future use of health services. We used data from the VHS, a prospective study of patients receiving ambulatory care services in 4 Veterans Affairs outpatient clinics in the greater Boston area. Three hundred fifty-two (14.5%) patients were identified as having CLD through self-report of having a physician's diagnosis of chronic bronchitis, emphysema, or asthma, and either using inhaled medications or having a productive cough for most days for 3 months. Ordinary least-square regressions were used to ascertain the effects of CLD severity on functional health and health services use. Compared with peak expiratory flow rate, which explained only 10% and 2%, respectively, of the variance in the SF-36 physical component summary (PCS) and in future doctor visits, the symptom severity explained 19% and 19%, respectively, of the variance in PCS and future doctor visits, after adjusting for age, education, and household income. The symptom severity measure is a strong predictor of future functional health (at 12 months of the VHS baseline) and health services use (within 6 months following the baseline). The study findings indicate that our measure of CLD severity is an efficient and easy-to-use approach that can be readily administered in ambulatory setting. It can be used as a case-mix adjustment in evaluating health outcomes and in predicting future utilization of health services.

Dissemination of methods and results from the veterans health study: final comments and implications for future monitoring strategies within and outside the veterans healthcare system.

The Veterans Health Study (VHS) followed a cohort of patients receiving ambulatory care in the Veterans Affairs healthcare system for up to 5 years. One of the principal aims of this study was to develop a library of methodologies including general and disease-specific health outcome questionnaires for use in monitoring the quality of healthcare and for research purposes. The cornerstone for this work is the Veterans RAND 36 and 12 Item Health Surveys (VR-36 and VR-12), a general measure developed in the VHS for measuring the physical and psychologic well-being of the patient. A comprehensive set of disease-specific assessments has also been developed as part of this study for the purposes of monitoring specific chronic conditions more commonly seen in routine ambulatory care settings. Since 1996, more than 2 million questionnaires have been administered in the VA for quality monitoring purposes, using the VR-36 and VR-12. Research studies that have used these batteries span randomized clinical trials in the VA cooperative studies program and clinical effectiveness research. Health assessments using VHS batteries are being disseminated for widespread use outside the VA. Chief among the assessments used is the VR-12, which has recently been included in the 2006 Health Plan Employer Data and Information Set (HEDIS) as part of the Medicare Health Outcomes Survey for monitoring the Medicare Advantage Program. The methods and batteries developed in the VHS are in the public domain and provide a framework for future patient monitoring using standard measures of health.

Applications of methodologies of the Veterans Health Study in the VA healthcare system: conclusions and summary.

The Veterans Health Study (VHS) had as its overarching goal the development, testing, and application of patient-centered assessments for monitoring patient outcomes in ambulatory care in large integrated care systems such as the Department of Veterans Affairs (VA). Unlike other previous studies, the VHS has capitalized on rich administrative databases restricted to the VA and linked to patient-centered outcomes. The VHS has developed a comprehensive set of general and disease-specific measures for use by systems of care for ambulatory patients. Chief among these assessments is the Veterans SF-36 Health Survey for measuring health-related quality of life in veteran ambulatory populations. The Veterans SF-36 Health Survey provides the cornerstone for this study and historically has been extensively disseminated and used in the VA with close to 2 million administrations nationally as part of its quality management system. National surveys administered by the VA since 1996 using the Veterans SF-36 Health Survey indicate important regional differences with implications for varying resource needs. Based upon the rich foundation provided by the VHS methodology, the VA has implemented some of these approaches as part of its quality monitoring system and can serve as a model for other large integrated systems of care.

Risk-adjusted mortality as an indicator of outcomes: comparison of the Medicare Advantage Program with the Veterans' Health Administration.

BACKGROUND: The Medicare Advantage Program (MAP) and the Veterans' Health Administration (VHA) currently provide many services that benefit the elderly, and a comparative study of their risk-adjusted mortality rates has the potential to provide important information regarding these 2 systems of care. OBJECTIVE: The objective of this retrospective study was to compare mortality rates between the MAP and the VHA after controlling for case-mix differences. SUBJECTS: This study consisted of 584,294 MAP patients and 420,514 VHA patients. MEASURES: We used the Death Master File to ascertain the vital status of each study subject over approximately 4 years. We used Cox regression models to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the MAP compared with VHA patients. RESULTS: The average age for male MAP patients was 73.8 years (+/- 5.6) and for male VHA patients was 74.05 years (+/- 6.3). Unadjusted mortality rates of males for VHA and MAP were 25.7% and 22.8%, respectively, over approximately 4 years (P < 0.0001), respectively. The case-mix of VHA patients, however, was sicker than those from MAP. After adjusting for case-mix, the HR for mortality in the MAP was significantly higher than that in the VHA (HR, 1.404; 95% CI = 1.383-1.426). We obtained similar results when we compared the mortality rates of females for VHA and MAP. CONCLUSIONS: After adjusting for their higher prevalence of chronic disease and worse self-reported health, mortality rates were lower for patients cared for in the VHA compared with those in the MAP. Further studies should examine what differences in care structures and processes contribute to lower mortality in the VHA.

Use of risk-adjusted change in health status to assess the performance of integrated service networks in the Veterans Health Administration.

OBJECTIVE: Health outcome assessments have become an expectation of regulatory and accreditation agencies. We examined whether a clinically credible risk adjustment methodology for the outcome of change in health status can be developed for performance assessment of integrated service networks. STUDY DESIGN: Longitudinal study. SETTING: Outpatient. STUDY PARTICIPANTS: Thirty-one thousand eight hundred and twenty-three patients from 22 Veterans Health Administration (VHA) integrated service networks were followed for 18 months. MAIN MEASURE: The physical (PCS) and mental (MCS) component scales from the Veterans Rand 36-items Health Survey (VR-36) and mortality. The outcomes were decline in PCS (decline in PCS scores greater than -6.5 points or death) and MCS (decline in MCS scores greater than -7.9 points). RESULTS: Four thousand three hundred and twenty-eight (13.6%) patients showed a decline in PCS scores greater than -6.5 points, 4322 (13.5%) had a decline in MCS scores by more than -7.9 points, and 1737 died (5.5%). Multivariate logistic regression models were used to adjust for case-mix. The models performed reasonably well in cross-validated tests of discrimination (c-statistics = 0.72 and 0.68 for decline in PCS and MCS, respectively) and calibration. The resulting risk-adjusted rates of decline in PCS and MCS and ranks of the networks differed considerably from unadjusted ratings. CONCLUSION: It is feasible to develop clinically credible risk adjustment models for the outcomes of decline in PCS and MCS. Without adequate controls for case-mix, we could not determine whether poor patient outcomes reflect poor performance, sicker patients, or other factors. This methodology can help to measure and report the performance of health care systems.

Comprehensive health status assessment of centenarians: results from the 1999 large health survey of veteran enrollees.

BACKGROUND: Information on the health status of centenarians provides a means for understanding the health care needs of this growing population. Therefore, we examined the health status of a national cohort of centenarian veteran enrollees. METHODS: Ninety-three centenarian veteran enrollees returned a complete health history questionnaire, which included questions about sociodemographic information, age-associated conditions, health behaviors, health-related quality of life as measured by the Veterans SF-36, and change in health status. RESULTS: Centenarian veteran enrollees are a group with major impairment across multiple dimensions of health-related quality of life despite having a relatively low prevalence of diseases. They had considerable physical limitations as reflected by their physical health summary scores (26.2 +/- 8.3). However, their mental health was comparatively good (mental health summary score 44.1 +/- 12.5). Compared to younger elderly veterans (ages 85-99), centenarians had a lower prevalence of hypertension, angina or myocardial infarction, diabetes, and chronic low back pain (p <.05). Centenarians had significantly worse physical functioning, role physical, vitality, and social functioning scores than did younger elderly veterans. The two groups did not differ in their general health, bodily pain, role emotional, and mental health scores. Centenarians did not perceive much decline in their physical or mental health during the preceding year. CONCLUSIONS: Centenarian veteran enrollees are a group with a low number of age-associated diseases and good mental health despite substantial physical limitations. These results support future studies of services directed toward improvement of function as opposed to those focused solely on the treatment of diseases.

Measurement comparisons of the medical outcomes study and veterans SF-36 health survey.

The Medicare Health Outcomes Survey (HOS) uses the Medical Outcomes Study (MOS) SF-36 among beneficiaries enrolled in Medicare managed care programs, whereas the Department of Veterans Affairs (VA), Veterans Health Administration (VHA) has administered the Veterans version of the SF-36 for quality management purposes. The Veterans version is comparable to the MOS version for 6 of the 8 scales, but distinctly different in role physical (RP) and role emotional (RE) scales. The gains in precision for the Veterans SF-36 provide evidence for the use of this version in future applications for assessing patient outcomes across health care systems.