Comparing generic and disease-specific measures of physical and role functioning: results from the Veterans Health Study

Validation and Factor Analysis of the Lithuanian Version of the Dizziness Handicap Inventory

OBJECTIVES

This study aimed to validate the Lithuanian version of the Dizziness Handicap Inventory (DHI-L), investigate its reliability, and perform factor analysis.

MATERIALS AND METHODS

A standard protocol of translation was followed for psychometric instruments. A total of 108 patients (75.9% women), mean age 51.9 years, with peripheral or central dizziness and vertigo participated in our cross-sectional study. The internal consistency was measured by Cronbach's alpha coefficient and corrected item-total correlations (CI-TCs). After a week, 65 of the recruited patients were again asked to fill out Dizziness Handicap Inventory (DHI)-L to ascertain test-retest reliability (intraclass correlation, ICC). Concurrent validation was performed using Pearson correlation between the total score and subscales of DHI-L and the eight scales of Short Form-36 Health Survey (SF-36). Finally, the factor structure of the DHI was assessed by principal component analysis (PCA).

RESULTS

The Cronbach's alpha coefficient was very high (0.91). CI-TCs for DHI-L total scale ranged from 0.33 to 0.67. The correlations between DHI and SF-36 were high to weak. The ICC was excellent for the total score and its subscales. Our proposed two-factor model explained 44.5% of the variance. The first factor indicated disability in daily activities and psychological effect of handicap. The second factor comprised of items that pertained to postural instability.

CONCLUSION

The DHI-L has shown good reliability and validity. Results did not support the original subscale structure of the DHI. As more studies need to be done to restructure DHI, we recommend only using the total DHI score as a measure of dizziness handicap.

Social Participation of Burn Survivors and the General Population in Work and Employment: A Life Impact Burn Recovery Evaluation (LIBRE) Profile Study

INTRODUCTION

Work integration and retention after burn injury is a key outcome. Little is known about how burn survivors reintegrate into the workplace. This article compares scores on the Life Impact Burn Recovery Evaluation (LIBRE) Profile, a burn-specific measure of social participation, between burn survivors and general population samples, focusing on the Work and Employment domain.

METHODS

Convenience samples of burn survivors and the U.S. population were obtained. Differences in demographic and clinical characteristics and LIBRE Profile scores were assessed. To examine work and employment, we compared family and friends, social activities, and social interactions scores among working vs nonworking burn survivors.

RESULTS

Six hundred and one burn survivors (320 employed) and 2000 U.S. residents (1101 employed) were surveyed. The mean age (P = .06), distributions of sex (P = .35), and Hispanic ethnicity (P = .07) did not differ significantly. Distributions of race (P < .01) and education (P = .01) differed significantly. The burn survivor sample had higher scores, demonstrating higher participation, for work and employment (mean = 49.5, SD = 9.42) than the general sample (mean = 46.94, SD = 8.94; P < .0001), which persisted after adjusting for demographic characteristics. Scores on the three domains administered to all respondents were higher (P < .001) for working than nonworking burn survivors.

CONCLUSION

Distributions indicated higher social participation in the burn survivor sample than the general sample. Possible explanations include sample bias; resilience, posttraumatic growth, or response-shift of survivors; and limitations of using items in the general sample. Working burn survivors scored higher than those not working. Future work can explore factors that mediate higher scores and develop interventions.

Measuring quality of life of primary antibody deficiency patients using a disease-specific health-related quality of life questionnaire for common variable immunodeficiency (CVID_QoL)

Background

Common variable immunodeficiency (CVID) and other primary antibody deficiencies (PAD) are a heterogeneous group of > 300 congenital disorders affecting the immune system. Until recently, efforts to measure health-related quality of life (QoL) in PAD patients have utilised generic QoL tools and disease-specific tools for other conditions. Still, the full impact of the disease is probably not understood. We evaluated the performance of the CVID_QoL, a novel disease-specific QoL instrument for adults with CVID, on Norwegian PAD patients and compared the results to those of the generic WHOQOL-BREF.

Methods

Respondents were recruited through the Norwegian Centre for Rare Disorders’ patient database. Included patients fulfilled the following criteria (all three): 1.) Age ≥18 years, 2.) a PAD diagnosis, 3.) currently on immunoglobulin therapy. The CVID_QoL is a 32-item questionnaire. Global CVID_QoL scores were compared between Norwegian PAD patients and Italian CVID patients.

Results

In total, 83 PAD patients filled out the CVID_QoL, 63% had CVID, 76% were females. 32 patients filled out the WHOQOL-BREF. Feasibility was high (<1% missing). Internal consistency for the emotional- (Cronbach’s α-value = 0.91) and relational functioning (α =  0.77) subscales was high, but questionable for the gastrointestinal and skin symptoms subscale (α =  0.66). Convergent validity varied from weak to strong (range 0.3–0.8). Floor and ceiling effects were present.

Conclusions

Although many disease-specific characteristics are probably shared with CVID and other PAD, the CVID_QoL captures some, but not all, dimensions of PAD patients’ QoL. More evaluations of the CVID_QoL’s performance in different contexts are needed.

Electronic supplementary material

The online version of this article (10.1186/s41687-019-0101-x) contains supplementary material, which is available to authorized users.

Initial development and validation of a mitochondrial disease quality of life scale

Mitochondrial diseases are a clinically diverse group of genetic disorders that often present to neurologists. Health related quality of life (HRQOL) is increasingly recognised as a fundamental patient based outcome measure in both clinical intervention and research. Generic outcome measures have been extensively validated to assess HRQOL across populations and different disease states. However, due to their inclusive construct, it is acknowledged that not all relevant aspects of a specific illness may be captured. Hence there is a need to develop disease specific HRQOL measures that centre on symptoms characteristic of a specific disease or condition and their impact. This study presents the initial conceptualisation, development and preliminary psychometric assessment (validity and reliability) of a mitochondrial disease specific HRQOL measure (Newcastle Mitochondrial Quality of life measure (NMQ)). NMQ is a valuable assessment tool and consists of 63 items within 16 unidimensional domains, each demonstrating good internal reliability (Cronbach's α≥0.83) and construct validity.

Reliability and validity of the Functional Assessment of Human Immunodeficiency Virus Infection (FAHI) in patients with drug and alcohol use disorders

Human Immunodeficiency Virus (HIV) and substance use disorders can both significantly impact a patient's quality of life (QOL), and it is, therefore, important to assess QOL throughout treatments for these chronic conditions. This study evaluated the psychometric properties of the Functional Assessment of Human Immunodeficiency Virus Infection (FAHI) in 170 HIV-positive patients who participated in a substance abuse treatment study. Internal consistency of the FAHI was good. Convergent and discriminant validity were generally supported with comparisons to other patient-reported measures. FAHI scores were not significantly associated with viral loads or CD4 counts, and they were similar in patients with and without AIDS. Patients who achieved longer durations of drug and alcohol abstinence during treatment reported better QOL post-treatment. The FAHI appears to be a reliable and valid measure for assessing QOL in HIV-positive patients with concurrent drug and alcohol use disorders.

Meta-analyses of the effect of false-positive mammograms on generic and specific psychosocial outcomes

OBJECTIVES

While a previous meta-analysis found that false-positive mammography results affect women's likelihood of returning for screening, effects on well being have yet to be meta-analyzed. We investigated whether the effects of false-positive mammograms on women's well-being are limited to outcomes specific to breast cancer.

METHODS

We searched MEDLINE for studies of the psychosocial effects of false-positive results of routine screening mammography. We pooled effect sizes using random effects meta-analysis.

RESULTS

Across 17 studies (n=20781), receiving a false-positive mammogram the result was associated with differences in all eight breast-cancer-specific outcomes that we examined. These included greater anxiety and distress about breast cancer as well as more frequent breast self-exams and higher perceived effectiveness of screening mammography. False positives were associated with only one of six generic outcomes (i.e. generalized anxiety), and this effect size was small.

CONCLUSIONS

False-positive mammograms influenced women's well-being, but the effects were limited to breast-cancer-specific outcomes. Researchers should include disease-specific measures in future studies of the consequences of false-positive mammograms.

Measurement invariance of the kidney disease and quality of life instrument (KDQOL-SF) across veterans and non-veterans

BACKGROUND

Studies have demonstrated that perceived health-related quality of life (HRQOL) of patients receiving hemodialysis is significantly impaired. Since HRQOL outcome data are often used to compare groups to determine health care effectiveness it is imperative that measures of HRQOL are valid. However, valid HRQOL comparisons between groups can only be made if instrument invariance is demonstrated. The Kidney Disease Quality of Life-Short Form (KDQOL-SF) is a widely used HRQOL measure for patients with chronic kidney disease (CKD) however, it has not been validated in the Veteran population. Therefore, the purpose of this study was to examine the measurement invariance of the KDQOL-SF across Veterans and non-Veterans with CKD.

METHODS

Data for this study were from two large prospective observational studies of patients receiving hemodialysis: 1) Veteran End-Stage Renal Disease Study (VETERAN) (N = 314) and 2) Dialysis Outcomes and Practice Patterns Study (DOPPS) (N = 3,300). Health-related quality of life was measured with the KDQOL-SF, which consists of the SF-36 and the Kidney Disease Component Summary (KDCS). Single-group confirmatory factor analysis was used to evaluate the goodness-of-fit of the hypothesized measurement model for responses to the subscales of the KDCS and SF-36 instruments when analyzed together; and given acceptable goodness-of-fit in each group, multigroup CFA was used to compare the structure of this factor model in the two samples. Pattern of factor loadings (configural invariance), the magnitude of factor loadings (metric invariance), and the magnitude of item intercepts (scalar invariance) were assessed as well as the degree to which factors have the same variances, covariances, and means across groups (structural invariance).

RESULTS

CFA demonstrated that the hypothesized two-factor model (KDCS and SF-36) fit the data of both the Veteran and DOPPS samples well, supporting configural invariance. Multigroup CFA results concerning metric and scalar invariance suggested partial strict invariance for the SF-36, but only weak invariance for the KDCS. Structural invariance was not supported.

CONCLUSIONS

Results suggest that Veterans may interpret the KDQOL-SF differently than non-Veterans. Further evaluation of measurement invariance of the KDQOL-SF between Veterans and non-Veterans is needed using large, randomly selected samples before comparisons between these two groups using the KDQOL-SF can be done reliably.

The quality of life of patients after a lumbar microdiscectomy: a four-year monitoring study

INTRODUCTION/AIM

Health-conditioned quality of patients' life is equally a result of their subjective perception of the disease and their objective condition. The aim of this paper is to evaluate the quality of life of surgically treated lumbar radiculopathy patients by using a generic and a lumbar disease-specific questionnaire.

METHODOLOGY

50 patients were evaluated (average age: 44.9 years; 52 male and 48 female). Two questionnaires were used for this purpose: the SF36 generic questionnaire, measuring eight quality of life domains divided into two sub-domains (overall physical and overall mental health), and the NASS LBP lumbar disease-specific questionnaire measuring four domains (pain and disability, motor and sensory neurogenic symptoms, expectations from the treatment and satisfaction with it). The results of the physical domain (SF36-PHYS) are low at the beginning of monitoring (25.7); they increase over the following 6 months (46.4) and drop insignificantly after 4 years (45.9). The mental health value (40.4) remained unchanged as compared to that of the general population. Values of the physical functioning domain reach that of the general population (80.0) after 6 months. Neurogenic symptoms domain results (NASS LBP-NS) do not correlate with other scales and domains. The conclusion is that the quality of life of patients after a lumbar microdiscectomy deteriorates significantly from a physical point of view immediately after it. It normalizes over the following 6 months, though a certain degree of physical damage still remains. Mental health alteration is not specific for lumbar radiculopathy. The neurogenic symptoms domain is the least improved dimension of their quality of life: it is very specific and to be evaluated with a special test set.

Coping and acceptance: the greatest challenge for veterans with intestinal stomas

OBJECTIVE

Intestinal stomas (ostomies) create challenges for veterans. The goal of this qualitative analysis was to understand better patients' perspectives regarding their greatest challenge.

METHODS

Ostomates at three Veterans Affairs locations were surveyed using the modified City of Hope Quality of Life-Ostomy questionnaire that contained an open-ended request for respondents to describe their greatest challenge. The response rate was 51% (239 of 467); 68% (163 of 239) completed the open-ended item. Content analysis was performed by an experienced qualitative research team.

RESULTS

Coping and acceptance were the most commonly addressed themes. The most frequently expressed issues and advice were related to a need for positive thinking and insight regarding adjustment over time. Coping strategies included the use of humor, recognition of positive changes resulting from the stoma, and normalization of life with an ostomy.

CONCLUSIONS

Coping and acceptance are common themes described by veterans with an intestinal stoma. Health-care providers can assist veterans by utilizing ostomate self-management strategies, experience, and advice.

Validity, reliability, and responsiveness of the Kansas City Cardiomyopathy Questionnaire in anemic heart failure patients

BACKGROUND

While generic health status measures quantify the impact of all patients' diseases on their health-related quality of life, disease specific measures focus on only one of the many conditions that a patient may have. If a patient has two diseases with similar clinical manifestations, they may respond differently to a disease-specific instrument if one of their conditions improves while the other worsens or remains stable, thus undermining the instruments in that patient population. We sought empirical evidence of the reliability and validity (including responsiveness) of the Kansas City Cardiomyopathy Questionnaire (KCCQ), a disease-specific measure for heart failure (HF), among HF patients with and without anemia, a condition that has similar symptoms to HF.

METHODS

This work used a prospective cohort study of 811 HF outpatients from 58 U.S. centers with a baseline assessment of anemia of whom 698 were followed for 3 months with serial health status measures.

RESULTS

Among participants, 268 (33%) were anemic. The construct validity of the KCCQ was supported by showing similar correlations with the New York Heart Association (NYHA) classification in patients with and without anemia (P value for interaction = 0.38). The internal consistency (Cronbach's alpha = 0.92 and 0.93 for anemic and non-anemic patients, respectively) and test-retest reliability (mean 3-month change scores in stable patients = -2.8 [SD = 1.4] and -0.5 [SD = 0.8], P = 0.14) were similar. Estimates of responsiveness were also similar.

CONCLUSION

This study provides empirical evidence that the psychometric properties of the KCCQ are similar in patients with or without anemia, a potentially confounding clinical condition in patients with heart failure.

Dissemination of Methods and Results From the Veterans Health Study

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.

Older and Younger Adults in Pain Management Programs in the United States: Differences and Similarities

OBJECTIVES

1) To investigate health status of older (>or=60 years) and younger adults (<60 years) with chronic pain and to separately compare that with existing normative data; and 2) to examine more fully differences in health status between younger and older adults with chronic pain and explore their geographic variation across three multidisciplinary pain programs in the Pacific, Mountain, and New England regions of the United States.

DESIGN

We performed a cross-sectional analysis.

PATIENTS

Initial assessments of 6,147 patients dating from January 1998 to January 2003 were used.

OUTCOMES MEASURES

We used the Treatment Outcomes of Pain Survey (TOPS), a disease-specific instrument that includes the Short Form-36.

RESULTS

The health status of the older pain patients in terms of their actual scores was comparable with that of younger pain patients across the three sites. Health status is impaired to a lesser degree in older than in younger adults with chronic pain as compared with normative adults. Statistically significant differences were found in a number of domains of the TOPS. Older adults with chronic pain present with pain intensity similar to that of younger patients with chronic pain, but report better mental health (P < 0.002), less fear-avoidance (P < 0.05), less passive coping (P < 0.0001), more life control (P < 0.05), and more lower body physical limitations (P < 0.005) than younger patients with chronic pain.

CONCLUSIONS

Older adults with chronic pain differ in a number of important domains from younger adults with chronic pain: overall the former present with greater physical, and less psychosocial impairment.

Posttraumatic Stress Disorder and Health Status

This article examines the association between self-reported prevalence of posttraumatic stress disorder (PTSD) and health status in a sample of 2425 male Department of Veterans Affairs (VA) ambulatory care patients who participated in the Veterans Health Study. Participants were recruited at 1 of 4 VA outpatient clinics in the Boston area. They completed self-report measures of PTSD (using the PTSD Checklist and measures of exposure to traumatic events), depression (using the Center for Epidemiologic Studies--Depression scale), and health status (using the Short-Form-36) and a medical history interview assessing 22 conditions and a history of psychiatric treatment. The screening prevalence of PTSD was 20.2% among all patients (24.3% among those exposed to traumatic events); another 15.5% met the criteria for depression but not PTSD. The health status of patients with either PTSD or depression was significantly worse than that of patients with neither disorder, even after controlling for age, education, and number of comorbid medical conditions. Patients with PTSD reported more medical conditions than did other patients. Patients with PTSD currently in mental health treatment had worse health status than did those who reported no treatment; the health status of patients who reported past mental health treatment was generally comparable to that of those with no treatment. The prevalence and comorbidity of PTSD among this sample of VA ambulatory care patients were higher than previously reported among samples of community-residing adults. The association of PTSD with health status was substantial, suggesting that the burden of PTSD is at least comparable to, and may be worse than, that of depression. Mental health treatment alleviated some of this burden. The potential impact of PTSD on health status should be more widely recognized.

The impact of non-traumatic hip and knee disorders on health-related quality of life as measured with the SF-36 or SF-12. A systematic review

OBJECTIVES

The purpose of this review is to summarize the available evidence on the impact of non-traumatic hip or knee disorders on health-related quality of life (HRQL), as measured with the Short Form 36 Health Survey (SF-36) or Short Form 12 Health Survey (SF-12), by comparing this with data from reference populations.

METHODS

Studies were identified by an electronic search of the MEDLINE, PsychInfo and Cinahl databases. Studies with the following features were included: study population included patients with non-traumatic hip or knee disorders, the SF-36 or SF-12 was used as an outcome measure and mean scores on these HRQL measures were presented. Using mean HRQL scores from the selected studies and scores from reference populations, z-scores were computed. Pooled estimates were computed for subgroups of studies with similar patients in similar settings.

RESULTS

A total of 40 studies met the inclusion criteria. Patients with non-traumatic hip and knee disorders scored up to 2.5 standard deviations (SDs) below reference population values, especially on the physical aspects of HRQL. Social and mental aspects were up to 1 SD below reference population values, especially in patients in clinical settings.

CONCLUSIONS

The impact of non-traumatic hip or knee disorders on HRQL is substantial, especially on the physical aspects of HRQL.

The Role of Generic and Disease-specific Measures of Physical and Role Functioning in Assessing Patient Outcomes

Using longitudinal data from the Veterans Health Study (VHS), we extended our earlier published cross-sectional analysis in comparing the generic SF-36 physical functioning (PF) and role limitations (role-physical [RP]) scales with the disease-specific PF and RP scales using disease attributions. The present study included 569 patients with chronic lung disease (CLD) and 352 patients with chronic low back pain (LBP) who received Veterans Affairs (VA) ambulatory care between June 1993 and March 1996. Consistent with our earlier study, we found that changes in the generic PF and RP scales had higher correlations with the other generic SF-36 scales than those in the disease-specific PF and RP scales over 12 months. On the other hand, disease-specific measures of PF and RP had larger R and t statistic values in discriminating the impacts of symptom-based illness severity as well as clinical services on physical and role functioning. These results suggest that the generic and disease-specific measures of PF and RP behave distinctly different from each other over time. The generic measures of PF and RP tend to assess a broad array of health-related quality of life, whereas disease-specific attributions of PF and RP scales tend to evaluate disease progression and clinical management associated with specific disease conditions. Disease-specific attribution is an important alternative to the development of new disease-specific instruments for assessing illness severity and the impact of clinical services.

A comparison of the discriminatory power of the Inflammatory Bowel Disease Questionnaire and the SF-36 in people with ulcerative colitis

The aim of this study was to compare the discriminatory power of a generic and a condition-specific quality of life measure (the Medical Outcomes Study Short-Form 36 (SF-36) and the Inflammatory Bowel Disease Questionnaire (IBDQ)) with respect to sub-groups defined by disease-related and other factors, in a sample of patients with ulcerative colitis. Disease activity was generally more highly correlated with IBDQ scores than with SF-36 scores. The only significant differences with respect to disease extent were in the SF-36 energy/vitality and social function domains. Age was negatively and weakly to moderately correlated with the physical domains of the SF-36 but positively though weakly correlated with scores on the IBDQ emotional domain and those domains of the SF-36 related to mental well-being. Co-existing chronic illness, even on controlling for age, was associated with significantly poorer scores on the generic measure, but had little influence on IBDQ scores. In conclusion, generic and disease-specific measures of quality of life appear to be complementary rather than interchangeable. We recommend the use of both types of measure in parallel.

Intraindividual change in SF-36 in ambulatory clinic primary care patients predicted mortality and hospitalizations

OBJECTIVE

We sought to determine whether change in SF-36 scores over time is associated with the risk of adverse outcomes.

STUDY DESIGN AND SETTING

7,702 participants in the Ambulatory Care Quality Improvement Project who completed a baseline and 1-year SF-36. Using logistic regression methods we estimated the 1-year risk of hospitalization and death based on previous 1-year changes in the physical (PCS) and mental (MCS) component summary scores.

RESULTS

After adjusting for baseline PCS scores, age, VA hospital site, distance to VA, and comorbidity, a >10-point decrease in PCS score was associated with an increased risk of death (OR 2.3, 95% CI 1.6-3.4) and hospitalization (OR 1.8, 1.4-2.2). An increased risk was also seen with a >10-point decrease in the MCS (OR for death, 1.6, 1.1-2.3; OR for hospitalization 1.5, 1.2-1.8).

CONCLUSION

Change in SF-36 PCS and MCS scores is associated with mortality and hospitalizations, and provides important prognostic information over baseline scores alone.

Patient-reported measures of health: The Veterans Health Study

The goal of the Veterans Health Study (VHS) was to extend the work of the Medical Outcomes Study (MOS) into the VA, by developing methodology for monitoring patient-based outcomes of care for use in ambulatory outpatient care. The principal objective of the VHS was developing valid and reliable measures to assess general health-related quality of life (HRQoL) and identifying the presence of selected health conditions, their severity, and their impact on HRQoL. In this article, we provide an overview of the historical context, framework, objectives, and applications of the VHS for the purpose of assessing the health outcomes of veteran patients. The VHS is a prospective observational study that has followed 2425 VA patients for up to 2 years. The patients were sampled from users of the Veterans Affairs (VA) ambulatory care system in the Boston area. The health conditions selected were hypertension, diabetes, chronic lung disease, osteoarthritis of the knee, chronic low-back pain, and alcohol-related problems. These conditions were chosen because they are both prevalent in the VA and have measurable impacts on HRQoL. One of the cornerstones of the VHS was the development of the Veterans SF-36, modified from the MOS SF-36 for use in veteran ambulatory populations. Other key accomplishments included the development of patient-based disease-specific measures of health and the establishment of methods and logistics for comprehensive health outcomes research in large health care systems such as the VA, using these patient-based measures. Selected measures developed in the VHS, eg, the Veterans SF-36, have been integrated into the VA outcomes measurement system. The scope of the VHS is unique; it resulted in the development of a broad range of patient-focused process and outcome measures, as well as methodologies for assessing large numbers of patients, that have been widely used in the VA outpatient health care system for monitoring health outcomes across the nation.

Accounting for deaths in longitudinal studies using the SF-36: the performance of the Physical Component Scale of the Short Form 36-item health survey and the PCTD

BACKGROUND

Commonly used measures such as the Physical Component Scale of the Short Form 36-item health survey (PCS) are undefined at death, limiting longitudinal analyses to survivors, a healthier cohort that cannot be identified prospectively, and that might have had little change in health. One proposed approach is to transform the PCS into the Physical Component Transformed, with Deaths included (PCTD), which is the probability of being healthy 1 year later and for which deaths logically have a value of zero. Data missing for other reasons than death have not been considered.

OBJECTIVE

To examine the performance of the PCTD, to determine the influence of including deaths, the additional effects of imputing missing values and adjusting for covariates, and the calibration of the PCTD in different populations.

METHODS

We imputed missing values of the PCTD, calling the new variable the PCTDI. We compared the distributions of the PCS, PCTD, and PCTDI cross-sectionally and over time. In 3 different populations, we determined whether the PCTD accurately predicted the probability of being healthy 1 year later.

RESULTS

The patients who died did not have extreme values on the PCTD. The experience of the cohort was best described by the PCTDI. The calibration of the PCTD was surprisingly good in all the populations examined. Results were similar for the physical function index.

CONCLUSION

The PCTDI is an improvement over the PCS, in which patients who had died have no influence, and over the PCTD, where they might have too much influence. We recommend the PCTDI for longitudinal analyses of physical health when deaths occur, for primary or secondary analysis.

Development of a disease specific questionnaire to supplement a generic tool for QoL in colorectal cancer

The need for disease-specific quality of life measures is highlighted in the literature. The psychometric properties of a supplementary disease-specific quality of life questionnaire developed for use with a generic Quality of Life tool in colorectal cancer patients are explored. Originally developed and tested in a German sample, the English translation was tested on a cohort of UK colorectal cancer patients. Relevance and acceptability was previously established in Germany. A rigorous factor analysis ascertained the underlying structure of two factors with a number of single items that were retained as clinically important symptom indicators. In considering validity, four conditions were assessed: Reliability using Cronbach's alpha; Construct validity by comparing patient subgroups; Clinical Validity, by testing the hypothesis that some patient subgroups experience worse quality of life; Construct Reliability using second order factor analysis with the EORTC QOLQ-C30 scales, confirming that the factors retained provide an excellent measure of physical discomfort and a good measure of physical well being. Two other such questionnaires were developed in parallel with this one and reported in the literature (FACT-C and QOLQ-CR38). However, this questionnaire provides a useful alternative tool for use in clinical trials of colorectal cancer treatments alongside a core QoL questionnaire especially when brevity is an important consideration.

Patient characteristics and prescription patterns of atypical antipsychotics among patients with schizophrenia

BACKGROUND

Schizophrenia, one of the leading causes of disability, contributes substantially to the use of medical and mental health services. The treatment of schizophrenia is therefore particularly important to reduce deficits across a large number of neurocognitive domains.

OBJECTIVE

To describe the prescription (e.g. initiation and switching) patterns of atypical antipsychotic agents and examine the extent to which patient sociodemographic and clinical characteristics are associated with the prescription patterns of atypical antipsychotics among patients with schizophrenia.

METHODS

Using unique data sources from the Veterans Health Administration (VA), the study identified 89 107 patients with schizophrenia based on at least one inpatient or more than or equal to two outpatients' ICD-9-CM codes (> or =7 days apart). We defined a prior 6-month (1/1/99 to 6/30/99) and a post 6-month (7/1/99 to 12/31/99) period to describe patterns of initiation and switching of atypical antipsychotics.

RESULTS

Only a small number of patients were on clozapine (1.8%) and quetiapine (1.4%). More patients were prescribed olanzapine (23%) than risperidone (20%) (P < 0.001). Compared with patients who were on risperidone, those who were on olanzapine were younger (P < 0.001), more likely Hispanic (P < 0.001), more likely married (P < 0.05), had more service-connected disability (P < 0.001), had fewer numbers of physical comorbidities (P < 0.001), and a lower body mass index (BMI) (P < 0.05).

CONCLUSION

Olanzapine and risperidone appear to be prescribed to patients with different sociodemographic and clinical characteristics. Future research needs to explore the reasons for those differences.

Validation of case-mix measures derived from self-reports of diagnoses and health

Self-reported chronic diseases and health status are associated with resource use. However, few data exist regarding their ability to predict mortality or hospitalizations. We sought to determine whether self-reported chronic medical conditions and the SF-36 could be used individually or in combination to assess co-morbidity in the outpatient setting. The study was designed as a prospective cohort study. Patients were enrolled in the primary care clinics at seven Veterans Affairs (VA) medical centers participating in the Ambulatory Care Quality Improvement Project (ACQUIP). 10,947 patients, > or = 50 years of age, enrolled in general internal medicine clinics who returned both a baseline health inventory checklist and the baseline SF-36 who were followed for a mean of 722.5 (+/-84.3) days. The primary outcome was all-cause mortality, with a secondary outcome of hospitalization within the VA system. Using a Cox proportional hazards model in a development set of 5,469 patients, a co-morbidity index [Seattle Index of Co-morbidity (SIC)] was constructed using information about age, smoking status and seven of 25 self-reported medical conditions that were associated with increased mortality. In the validation set of 5,478 patients, the SIC was predictive of both mortality and hospitalizations within the VA system. A separate model was constructed in which only age and the PCS and MCS scores of the SF-36 were entered to predict mortality. The SF-36 component scores and the SIC had comparable discriminatory ability (AUC for discrimination of death within 2 y 0.71 for both models). When combined, the SIC and SF-36 together had improved discrimination for mortality (AUC = 0.74, p-value for difference in AUC < 0.005). A new outpatient co-morbidity score developed using self-identified chronic medical conditions on a baseline health inventory checklist was predictive of 2-y mortality and hospitalization within the VA system in general internal medicine patients.

Late Life Function and Disability Instrument: II. Development and evaluation of the function component

BACKGROUND

Self-reported capability in physical functioning has long been considered an important focus of research for older persons. Current measures have been criticized, however, for conceptual confusion, lack of sensitivity to change, poor reproducibility, and inability to capture a wide range of upper and lower extremity functioning.

METHODS

Using Nagi's disablement model, we wrote physical functioning questionnaire items that assessed difficulty in 48 common daily tasks. We constructed the instrument using factor analysis and Rasch analytic techniques and evaluated its validity and test-retest reliability with 150 ethnically and racially diverse adults aged 60 years and older who had a range of functional limitations.

RESULTS

Our analyses resulted in a 32-item function component with three dimensions--upper extremity, basic lower extremity, and advanced lower extremity functions. Expected differences in summary scores of known-functional limitation groups support its validity. Test-retest stability over a 1- to 3-week period was extremely high (intraclass correlation coefficients =.91 to.98).

CONCLUSIONS

The Late-Life Function and Disability Instrument has potential to assess activity concepts related to upper and lower extremity functioning across a wide variety of daily physical tasks and individual levels of physical functioning.

Persistent impaired emotional functioning in survivors of a myocardial infarction?

The quality of life (QoL) of survivors of a myocardial infarction (MI) remains lower than that of their peers long after the acute event. Previous research on this subject has indicated, however, that this difference might lessen somewhat over time for the dimension 'emotional functioning' (as measured by the sickness impact profile (SIP): a generic instrument for QoL). The present study explores this phenomenon further using two instruments that specifically measure emotional functioning i.e. the hospital anxiety and depression scale (HAD) and the heart patients psychological questionnaire (HPPQ). Ninety-nine participants of a large population-based cohort (the Rotterdam study), who had been admitted to the hospital because of an MI in the previous 6-60 months, and 101 reference subjects, without a history of infarction of heart or brain, from the same age and gender-groups, were interviewed twice (at 1- to 3-year time intervals). The results of the present study confirm earlier findings that the emotional functioning (in terms of 'anxiety', 'depression', 'well-being', 'feeling disabled', and 'displeasure') of MI survivors is impaired when compared to their unaffected peers. Moreover, they did not show any improvement in 'anxiety', 'depression', 'well-being' and 'displeasure' over time in the MI survivors. The results did, however, show that the difference between MI survivors and referents became less in time in the dimension 'feeling disabled'. This decrease was partly because MI survivors improved and partly because referents felt more disabled over time. One explanation for this might be that referents (51% aged 70 years and over) had difficulties in adapting emotionally to decreasing levels of physical functioning with increasing age, while the MI survivors tended to adjust to and accept the impairments they had contracted several years earlier.

Regional variations in health status

CONTEXT

Knowledge about variations in the health status of patients seeking primary care in different parts of the United States is limited.

OBJECTIVE

To examine regional variations in the physical and mental health of patients receiving primary care in the largest integrated health care system in the United States which is operated by the Department of Veteran Affairs (VA).

STUDY DESIGN AND SETTING

We performed a mailed, cross sectional survey of 54,844 patients who were enrolled in seven VA General Internal Medicine clinics.

RESULTS

Among the 30,690 patients who returned an initial set of screening questionnaires, the prevalence of common chronic conditions varied by as much as 60% among the seven clinics. Moreover, patients' general health (measured by the SF-36) also varied significantly in a pattern that mirrored the observed differences in the prevalence of chronic conditions. After adjustment for important comorbid illnesses and sociodemographic factors, geographic site accounted for a small percentage of the explained variance in patient assessed health status.

CONCLUSIONS

The substantial differences in the health of patients enrolled in different VA primary clinics have important implications for the evaluation of clinical performance and health outcomes. Most of these differences can be attributed to sociodemographic and comorbid factors.

Responsiveness of the Smoking Cessation Quality of Life (SCQoL) questionnaire

BACKGROUND

The Smoking Cessation Quality of Life (SCQoL) questionnaire was developed to quantify changes in self-reported functioning and well-being associated with the smoking cessation process and to facilitate comparisons among smokers, former smokers, and nonsmokers. The SCQoL includes 5 cessation-targeted scales and the 8 multi-item scales of the Medical Outcomes Study 36-Item Short-Form Health Survey.

OBJECTIVE

This study was conducted to assess the responsiveness of the SCQoL by analyzing associations between SCQoL scale scores and duration of smoking abstinence.

METHODS

The SCQoL was administered at a screening visit and 2 to 6 weeks after screening as part of a longitudinal study. Study participants included smokers who intended to quit smoking. Subjects were required to purchase nicotine inhalers and were prompted to quit smoking before follow-up. Based on self-reported duration of abstinence at follow-up, subjects were categorized as recidivists (0 days smoke free), short-term abstainers (1-7 days smoke free), or longer-term abstainers (>7 days smoke free). Kruskal-Wallis tests were used to compare changes in scale scores from screening to follow-up among the 3 groups.

RESULTS

The internal consistency reliability of the 13 SCQoL scales ranged from 0.67 to 0.92. Subjects who maintained abstinence for longer periods experienced smaller declines in health-related quality of life between the screening and follow-up assessments. Differences among the 3 groups were driven primarily by differences between recidivists and longer-term abstainers.

CONCLUSIONS

The results are consistent with research indicating that recidivists report a greater number of (and more severe) cessation-related symptoms than abstainers. The findings of this investigation provide evidence for the responsiveness of the SCQoL.

Assessing Individual Outcomes during Outpatient Multidisciplinary Chronic Pain Treatment by Means of an Augmented SF-36

OBJECTIVE

To meet the growing demand for objective outcomes measurement during treatment of chronic pain, we developed an instrument to track outcomes of individual patients.

METHOD

In a 2-phase study, existing and novel outcomes instruments were applied in an interdisciplinary pain management program. In the initial phase, 408 patients were administered the Short Form 36-item questionnaire and during phase 2, 437 patients (87 of whom were followed) were given an expanded (191-item) questionnaire.

RESULTS

When applied to individual patients, the Short Form 26-item questionnaire lacked measurement reliability for assessment of treatment outcomes and sensitivity to upper extremity or facial pathology, and failed to separate limitations of work versus everyday activity. A novel group of scales derived from responses to 61 questions, including the Short Form 36-item questionnaire, proved sufficiently reliable for routine follow-up of individual chronic pain patients.

CONCLUSIONS

This new Treatment Outcomes in Pain Survey allows assessment of individual patient outcomes, and aggregate or individual clinician performance, during interdisciplinary treatment of chronic pain.

Assessment of functional status, low back disability, and use of diagnostic imaging in patients with low back pain and radiating leg pain

We analyzed data from outpatients with chronic low back pain (LBP) in the Veterans Health Study (n = 563) to examine the relationship between localized LBP intensity and radiating leg pain in assessing patient functional status, low back disability, and use of diagnostic imaging. Based on the localized LBP intensity, the study subjects were divided into tertiles (low, moderate, and high intensity). The study subjects were also stratified by the extent of radiating leg pain. Using analysis of variance and multiple regression analysis, we compared the relative importance of localized LBP intensity and radiating leg pain in explaining the variability in the means of the SF-36 scales and low back disability days, and in the proportion of patients who had used diagnostic imaging. The results of the study indicate that measures of localized LBP intensity and radiating leg pain contribute separately to the assessment of patient functional status, low back disability, and use of diagnostic imaging. These results suggest that localized LBP intensity and radiating leg pain may represent two different approaches in assessing back pain severity. Future epidemiological and health services research should consider both measures in assessing the impact of LBP on patient functional status, low back disability, and use of diagnostic imaging.

Evaluating methods of restoring cartilaginous articular surfaces

Surgeons and scientists have developed various approaches to restoring cartilaginous articular surfaces with the intention of relieving pain and improving mobility for people with traumatic or degenerative damage to their synovial joints. These approaches can be divided into two categories: methods intended to stimulate formation of new cartilaginous tissue and transplantation of osteochondral allografts or autografts. Experimental studies have shown that multiple variations of these approaches can restore some form of cartilaginous articular surface, but formation or transplantation of cartilaginous tissue in an animal model does not prove that a given method has the potential to relieve joint symptoms or improve joint function in humans. The effort to restore cartilaginous articular surfaces has reached the point that investigators should now evaluate the experimental results of methods intended to restore cartilaginous articular surfaces in ways that will identify the most promising approaches to the solution of clinical problems. Important issues concerning the experimental models include the types of articular surface defects studied, the age of the animal, and differences in articular cartilage among species. Important considerations in assessing the outcome of procedures designed to restore an articular surface include the overall function of the animal or patient, the function of the joint, the structure of the joint, and the structure, composition, and mechanical properties of the new tissue. This approach to evaluating methods of restoring a cartilaginous articular surface assumes that the goal of any of these methods is to provide sustained improved joint function and decreased joint symptoms in people with traumatic or degenerative joint damage, and that tissues that differ from normal articular cartilage may achieve this goal.

The Marks Asthma Quality of Life Questionnaire: further validation and examination of responsiveness to change

We performed analyses to examine the structure, validity, and responsiveness to change of the Marks Asthma Quality of Life Questionnaire (AQLQ), originally validated in Australia in a self-administered format, among 539 U.S. subjects with asthma. Subjects were interviewed twice by telephone over an 18-month period. Based on factor analyses, the subscale structure of the AQLQ was modified slightly to eliminate item overlap among subscale scores. Cross-sectionally, total AQLQ scores were significantly correlated in expected directions with baseline asthma severity scores (r = 0.58), SF-36 physical (r = -0.66) and mental (r = -0.40) health status scores, and pulmonary function (FEV1% predicted, r = -0.14). Longitudinally, changes in AQLQ total and subscale scores were significantly (P<0.01) associated with changes in asthma severity and both physical and mental status. The AQLQ, administered by telephone, appears to be useful for assessing changes in the impact of adult asthma.