Quality of life in asthma. I. Internal consistency and validity of the SF-36 questionnaire

Asthma is a chronic disease in which social life is altered. The importance of restrictions on social life may be greater in severe asthma or when symptoms are not adequately controlled. General scales of quality-of-life (QOL) may be used to detect the importance of social life impairment, but it is not yet known whether the scores of such QOL measures are reliable and valid in asthmatic patients. A study was carried out in 252 patients with asthma of variable severity (FEV1 ranging from 25 to 131% of predicted) to assess the validity of a general QOL scale, the first French version of the SF-36 health status questionnaire (SF-36). This is based on 36 items selected to represent nine health concepts (physical, social, and role functioning; mental health; health perceptions; energy or fatigue; pain; and general health). All nine SF-36 category scores were highly significantly correlated with the severity of asthma assessed by the clinical score of Aas (p < 0.0007 to p < 0.0001). Eight SF-36 category scores were highly significantly correlated with FEV1 (p < 0.003 to p < 0.0001). A high internal reliability of SF-36 was found using the alpha coefficient of Cronbach (0.91 for the whole questionnaire). The SF-36 questionnaire is valid and reliable in asthma and can therefore be used to examine QOL in asthmatic and nonasthmatic patients and to determine to what extent asthma impairs social life.

Do depressed patients in different treatment settings have different levels of well-being and functioning?

Differences in the functioning and well-being of adult patients with current or past depressive disorder who visited clinicians of different specialties in health maintenance organizations, solo practices, or large multispecialty group practices were examined. For patients in different systems, there were no significant differences in functioning and well-being across 12 domains tested. Patients of mental health specialists had worse mental health and more limitations in social activities, whereas patients of medical clinicians had worse physical functioning, more pain, more physical/psychophysiologic symptoms, and worse health perceptions. Thus, each system of care had depressed patients with a similar functioning and well-being "burden" but specialty sectors had patients with slightly different functioning and well-being profiles, probably reflecting patient selection of type of provider.

Hypertension--when is the clinical problem solved? When quality of life is secured

The patient's opinion is central to the monitoring and improvement of health outcomes. The goal of treatment should be the preservation of function and well-being of the patient. Despite this, standardized assessments of patients' experiences of disease and treatment are not routinely collected in clinical research and medical practice. In an era of cost containment, it is essential to monitor health outcomes. A prototype for collection of relevant data can be found in the Medical Outcomes Study which tests methods for monitoring the results of medical care among patients with hypertension and other conditions. Results from this study have shown that there is good reason to be optimistic about the feasibility of standardized, self-administered questionnaires as a primary means of collection for patient outcome data. Furthermore, it is possible to create an enhanced data base and add to it routinely on a large scale across diverse health care settings. Details of the health outcome measures used in the Medical Outcomes Study are presented in this paper.

The MOS 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups

The widespread use of standardized health surveys is predicated on the largely untested assumption that scales constructed from those surveys will satisfy minimum psychometric requirements across diverse population groups. Data from the Medical Outcomes Study (MOS) were used to evaluate data completeness and quality, test scaling assumptions, and estimate internal-consistency reliability for the eight scales constructed from the MOS SF-36 Health Survey. Analyses were conducted among 3,445 patients and were replicated across 24 subgroups differing in sociodemographic characteristics, diagnosis, and disease severity. For each scale, item-completion rates were high across all groups (88% to 95%), but tended to be somewhat lower among the elderly, those with less than a high school education, and those in poverty. On average, surveys were complete enough to compute scales scores for more than 96% of the sample. Across patient groups, all scales passed tests for item-internal consistency (97% passed) and item-discriminant validity (92% passed). Reliability coefficients ranged from a low of 0.65 to a high of 0.94 across scales (median = 0.85) and varied somewhat across patient subgroups. Floor effects were negligible except for the two role disability scales. Noteworthy ceiling effects were observed for both role disability scales and the social functioning scale. These findings support the use of the SF-36 survey across the diverse populations studied and identify population groups in which use of standardized health status measures may or may not be problematic.

A quality of life study in five hundred and eighty-one duodenal ulcer patients. Maintenance versus intermittent treatment with nizatidine

Quality of life (QoL) is commonly assessed for evaluating the process and outcome of treatment but has not been studied in duodenal ulcer (DU) disease. The recently developed and validated Quality of Life in Duodenal Ulcer Patients (QLDUP) questionnaire allowed the study of various dimensions according to treatment regimens. This study was conducted to compare QoL over a one-year follow-up period in DU patients randomized to two treatment regimens: maintenance versus intermittent (no maintenance) treatment with nizatidine. A total of 581 patients with endoscopic evidence of DU healing were randomly allocated to receive either nizatidine 150 mg/day for one year (Group A) or intermittent treatment (Group B). In both groups, symptomatic relapses were treated with nizatidine 300 mg/day for 6 weeks. The QLDUP questionnaire, which provides a QoL profile from 54 items divided up into 15 dimensions, was completed by all patients at entry and again at the time of a visit every 2 months for one year. The one-year symptomatic relapse rates were 8.0% and 33.5% in Group A and Group B, respectively (p < 0.001). The intent-to-treat analysis showed that patients in Group A had better QoL scores than those in Group B as regards 8 QoL dimensions, including ulcer-specific and non-specific dimensions. Differences between treatments were significant after 4 months, and this was sustained until the one-year assessment. The overall gain in QoL was significantly greater in Group A than in Group B with respect to 11 QoL dimensions. In conclusion, maintenance treatment with nizatidine for DU improved QoL to a larger extent than when intermittent therapy was used.

Do depressed patients in different treatment settings have different levels of well-being and functioning?

Differences in the functioning and well-being of adult patients with current or past depressive disorder who visited clinicians of different specialties in health maintenance organizations, solo practices, or large multispecialty group practices were examined. For patients in different systems, there were no significant differences in functioning and well-being across 12 domains tested. Patients of mental health specialists had worse mental health and more limitations in social activities, whereas patients of medical clinicians had worse physical functioning, more pain, more physical/psychophysiologic symptoms, and worse health perceptions. Thus, each system of care had depressed patients with a similar functioning and well-being "burden" but specialty sectors had patients with slightly different functioning and well-being profiles, probably reflecting patient selection of type of provider.

Patients' ratings of outpatient visits in different practice settings. Results from the Medical Outcomes Study

OBJECTIVE

To determine how patients in different kinds of practices--solo or single specialty (SOLO), multispecialty group (MSG), or health maintenance organizations (HMOs)--and with fee-for-service (FFS) or prepaid physician payment arrangements evaluate their medical care.

DESIGN

Survey of adult outpatients after office visits, with sample weighted to represent population of patients visiting physicians in each practice type.

SETTING

Offices of 367 internists, family practitioners, endocrinologists, cardiologists, and nurse practitioners, in HMOs (prepaid only), MSGs (prepaid and FFS), and SOLO practices (prepaid and FFS).

PATIENTS

Adults (N = 17,671) at start of the Medical Outcomes Study.

OUTCOME MEASURES

Overall rating of the visit (five choices from excellent to poor). A random half of the sample also rated the provider's technical skills, personal manner, and explanations of care as well as time spent during the visit, the appointment wait, the office wait, the convenience of the office location, and telephone access.

RESULTS

Fifty-five percent of patients rated their visit overall as excellent, 32% very good, 11% good, and 2% fair or poor. Patients of SOLO practitioners were more likely (64%) to rate their visit excellent than MSG (48%) or HMO (49%) patients (P < .001). Patients of SOLO practitioners rated all aspects of care better than HMO patients did, most markedly appointment waits (64% vs 40% excellent; P < .0001) and telephone access (64% vs 33% excellent; P < .0001). Within SOLO and MSG practices, FFS patients rated most specific aspects better than prepaid patients, but these differences were not statistically significant and were inconsistent across cities. Adjusting for patients' demographics, diagnoses and self-rated health did not change results. Physicians with visit ratings in the lowest 20% were nearly four times as likely to be left by patients within 6 months than physicians in the highest 20% (16.7% vs 4.6%; P < .001).

CONCLUSION

Of the five practice type and payment method combinations, SOLO FFS patients rated their visits best and HMO patients worst. Whether FFS or prepaid, care was rated better in small than in large practices. Our study shows that a brief visit rating form can be used to compare practice settings and health plans, and that patient ratings predict what proportion of patients, on average, will leave their physicians in the next several months.

The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs

Cross-sectional data from the Medical Outcomes Study (MOS) were analyzed to test the validity of the MOS 36-Item Short-Form Health Survey (SF-36) scales as measures of physical and mental health constructs. Results from traditional psychometric and clinical tests of validity were compared. Principal components analysis was used to test for hypothesized physical and mental health dimensions. For purposes of clinical tests of validity, clinical criteria defined mutually exclusive adult patient groups differing in severity of medical and psychiatric conditions. Scales shown in the components analysis to primarily measure physical health (physical functioning and role limitations-physical) best distinguished groups differing in severity of chronic medical condition and had the most pure physical health interpretation. Scales shown to primarily measure mental health (mental health and role limitations-emotional) best distinguished groups differing in the presence and severity of psychiatric disorders and had the most pure mental health interpretation. The social functioning, vitality, and general health perceptions scales measured both physical and mental health components and, thus, had the most complex interpretation. These results are useful in establishing guidelines for the interpretation of each scale and in documenting the size of differences between clinical groups that should be considered very large.

Social support and stressful life events: age differences in their effects on health-related quality of life among the chronically ill

There is substantial evidence of individual variation in health-related quality of life measures that is not accounted for by age or disease condition. An understanding of factors that determine good health is necessary for maintained function and improved quality of life. This study examines the extent to which social support and stressful life events were more or less beneficial for the long-term physical functioning and emotional well-being of 1,402 chronically ill patients. Analyses, conducted separately in three age groups, showed that social support was beneficial for health over time regardless of age. In addition, low levels of support were particularly damaging for the physical functioning of older patients. Stressful life events impacted differentially on health-related quality of life; relationship events had an immediate effect on well-being which diminished with time; financial events had an immediate negative effect on functioning and well-being which persisted over time for middle-aged patients; bereavement had a delayed impact on quality of life, with the youngest patients especially vulnerable to its negative effects; work-related events had both negative and positive effects, depending on age group. Results reinforce the importance of identifying and dealing with psychosocial problems among patients with chronic disease.

The MOS 36-item short-form health survey (SF-36). I. Conceptual framework and item selection

A 36-item short-form (SF-36) was constructed to survey health status in the Medical Outcomes Study. The SF-36 was designed for use in clinical practice and research, health policy evaluations, and general population surveys. The SF-36 includes one multi-item scale that assesses eight health concepts: 1) limitations in physical activities because of health problems; 2) limitations in social activities because of physical or emotional problems; 3) limitations in usual role activities because of physical health problems; 4) bodily pain; 5) general mental health (psychological distress and well-being); 6) limitations in usual role activities because of emotional problems; 7) vitality (energy and fatigue); and 8) general health perceptions. The survey was constructed for self-administration by persons 14 years of age and older, and for administration by a trained interviewer in person or by telephone. The history of the development of the SF-36, the origin of specific items, and the logic underlying their selection are summarized. The content and features of the SF-36 are compared with the 20-item Medical Outcomes Study short-form.

Methods for assessing condition-specific and generic functional status outcomes after total knee replacement

Many assume that, relative to generic measures, condition-specific health measures are both more sensitive to the condition's severity and more specific because they are less affected by other conditions. We analyzed the sensitivity and specificity of the generic SF-36, condition-specific scales based on the SF-36, and condition-specific measures based on the Knee Society's Clinical Rating System in a study of osteoarthritis patients following knee replacement. As hypothesized, knee-specific role function and pain measures were more specific than generic measures among patients with other comorbid conditions, and less so among patients with only knee problems. Physical function scales of both types were equally specific. Clinical indicators based on x-ray and range of motion were only weakly related to all measures of function.

The validity and relative precision of MOS short- and long-form health status scales and Dartmouth COOP charts. Results from the Medical Outcomes Study

This study estimated the validity and relative precision (RP) of four methods (MOS long- and short-form scales, global items, and COOP Poster Charts) in measuring six general health concepts. The authors also tested whether and how precisely each method discriminated relatively well adult patients (N = 638) from those with only severe chronic medical (N = 168) and only psychiatric conditions (N = 163), as clinically defined. For comparisons between the well group and both medical and psychiatric groups, RP estimates favored long-form over short-form, multi-item scales, and favored multi-item scales over single-item global measures and poster charts. In relation to long forms, short-form multi-item scales achieved a median RP of .93; RP estimates for global items and poster charts were .81 and .67, respectively. Variations in RP across methods and concepts were linked to differences in the coarseness of measurement scales, reliability, and content (including the effects of chart illustrations). These variations in RP have implications for the interpretation of scores, the statistical power of comparisons between clinical groups, and the size of confidence intervals around individual patient scores.

How the medical comorbidity of depressed patients differs across health care settings: results from the Medical Outcomes Study

OBJECTIVE

Although depression is one of the most common problems of medical and psychiatric outpatients, it has not been clear whether the extent of medical comorbidity among depressed patients varies across major types of clinical settings in which depressed patients receive care--especially by type of treating clinician (general medical versus mental health specialty) or type of payment for services (prepaid versus fee-for-service).

METHODS

The authors examined these issues using data on 1,152 adult outpatients with current depressive symptoms and a lifetime history of unipolar depressive disorder who received care in one of three health care delivery systems in three U.S. sites.

RESULTS

Depressed patients had a similarly high prevalence (64.9%-71.0%) of any of eight common chronic medical conditions whether they were seen in the general medical or specialty mental health sector; however, those visiting medical clinicians had a significantly higher prevalence of the two most common chronic medical conditions, hypertension and arthritis. Among depressed patients with hypertension, those visiting the general medical sector were more likely to be taking antihypertensive medication than were those visiting the mental health specialty sector. Type of payment (prepaid versus fee-for-service) was unrelated to either prevalence or severity of comorbid medical conditions, suggesting that the typical depressed patient in all types of practices studied had medical comorbidity.

CONCLUSIONS

These data suggest that clinicians in all health care settings must be prepared to encounter chronic medical conditions and complaints in the depressed patients who visit them.

The patient comment card: a system to gather customer feedback

Continuous patient feedback can give important information to hospitals about the quality of care they provide. The Patient Comment Card (PCC), a brief form that can be used to gather open-ended comments from patients and to measure quality, was developed during a two-year period and was extensively evaluated in a series of three pilot tests involving more than 2,000 patients discharged from five hospitals. Evaluation results demonstrate that the questionnaire elicits useful comments from patients and can generate statistically reliable scores and valid quality measures. However, in a field trial in four hospitals, low response rates (15%-27%) reflected, first, lack of follow-up of non-respondents, and second, the fact that most of the PCC quality scores were upwardly biased; these inflated scores were likely to reflect the low response rate. Tools such as the PCC should be used judiciously, given the possible abuses and misinterpretations of hospital quality scores.

Paradigm for the management of patient outcomes

Health-status measurement is discussed, and a paradigm for the management of patient outcomes is described and applied to a patient case. Challenged not only to eradicate disease but to improve health, today's health-care professionals must examine the structure, process, and outcomes of care to ensure that optimal care is provided. Techniques for measuring outcomes have been developed; important indicators are functional status, general well-being, and the patient's assessment of care. An interdisciplinary team of physicians, social scientists, and public policy experts at The Health Institute, New England Medical Center, Boston, Massachusetts, studies ways of monitoring and improving the quality and efficiency of care. The team, which now includes a pharmacist, is working to develop practical systems of care whose outcomes can be tested in patients at the medical center. The paradigm developed for the management of patient outcomes begins with evaluation based on results of history, physical examination, and diagnostic tests. Problems and goals (therapeutic endpoints) are then defined, and the safest, most effective, and least costly treatment is selected. Treatment is monitored for subjective and objective results and adjusted as necessary. The achievement of each endpoint contributes to improvement of the patient's health. Knowledge of health-status measurement will enable pharmacists to increase their contribution to patients' health.

A health status questionnaire using 30 items from the Medical Outcomes Study. Preliminary validation in persons with early HIV infection

Many current health status instruments either are too long to use in many acquired immune deficiency syndrome (AIDS) clinical trials or omit important concepts. In this study, human immunodeficiency virus (HIV)-relevant items developed for the Medical Outcomes Study (MOS) from subscales for cognitive function, energy/fatigue, health distress, and a single quality of life item were added to a portion of the MOS Short-form General Health Survey. The resulting 30-item questionnaire reliably and distinctly measured ten aspects of health and took less than 5 minutes to complete. To test its validity, this modified measure was used to compare the health of 73 subjects with asymptomatic HIV infection and 44 with early AIDS-related complex (ARC). Compared with ARC subjects, asymptomatic individuals reported superior overall health, less pain, and better physical function, role function, cognitive function, and quality of life (rank-sum, P less than 0.02). Asymptomatic subjects' scores were higher on most subscales than the age-adjusted scores of MOS outpatients with hypertension, diabetes, recent myocardial infarction, or depression; ARC patients scored closest to hypertensive patients. This instrument, containing a subset of the MOS measures of health-related quality of life, may be a useful outcome measure for AIDS clinical trials.

Effects of cost sharing in health insurance on disability days

We assess how cost sharing for medical services affects restricted activity days (RADs) and work loss disability days (WLDs), using data from a controlled experiment. We grouped the experimental insurance plans into four categories, one providing free care and the other three requiring varying amounts of cost sharing. RADs per person per year decreased by one to two days with greater cost sharing, with the strongest effects among those of average or poor health status, especially the non-poor. Unlike RADs, WLDs showed no systematic differences by plan.