Danny Ruta

The SF36 health survey questionnaire: an outcome measure suitable for routine use within the NHS?

OBJECTIVE--To assess the validity, reliability, and acceptability of the short form 36 (SF 36) health survey questionnaire (a shortened version of a battery of 149 health status questions) as a measure of patient outcome in a broad sample of patients suffering from four common clinical conditions. DESIGN--Postal questionnaire, followed up by two reminders at two week intervals. SETTING--Clinics and four training practices in north east Scotland. SUBJECTS--Over 1700 patients aged 16-86 with one of four conditions--low back pain, menorrhagia, suspected peptic ulcer, or varicose veins--and a comparison sample of 900 members of the general population. MAIN OUTCOME MEASURES--The eight scales within the SF36 health profile. RESULTS--The response rate exceeded 75% in the patient population (1310 respondents). The SF36 satisfied rigorous psychometric criteria for validity and internal consistency. Clinical validity was shown by the distinctive profiles generated for each condition, each of which differed from that in the general population in a predictable manner. Furthermore, SF36 scores were lower in referred patients than in patients not referred and were closely related to general practitioners perceptions of severity. CONCLUSIONS--These results provide support for the SF36 as a potential measure of patient outcome within the NHS. The SF36 seems acceptable to patients, internally consistent, and a valid measure of the health status of a wide range of patients. Before it can be used in the new health service, however, its sensitivity to changes in health status over time must also be tested.

A NEW APPROACH TO THE MEASUREMENT OF QUALITY OF LIFE : THE PATIENT-GENERATED INDEX

Quality of life has been defined as “the extent to which our hopes and ambitions are matched by experience.” To improve a patients quality of life through medical care would be to “narrow the gap between a patients hopes and expectations and what actually happens.” Using the above definition as a conceptual basis, we produced a self-administered, Patient-Generated Index (PGI) of quality of life. The PGI was completed by 359 patients presenting with low back pain. The validity of the measure was assessed by correlating patients PGI scores with a well-validated health profile, the Short-Form 36-item Health Survey (SF-36), and with their scores on a clinical back pain questionnaire. Stepwise multiple regression was then used to model the relationship between the PGI score and the SF-36. Patients PGI scores showed a high correlation with SF-36 scales measuring pain, social functioning, and role limitations attributable to physical problems, and with the clinical questionnaire. Together with whether a person was retired or not, these health variables were able to explain 25% of the variance in PGI scores. Patient generated index scores were significantly lower in patients referred to hospital compared with those managed solely in general practice and tended to reflect the general practitioners assessment of symptom severity. We conclude that it is possible to construct a questionnaire that quantifies the effect of a medical condition on patients quality of life in a way that has meaning and relevance in the context of their daily lives. The PGI has considerable potential for routine use in a wide range of clinical conditions for which the measurement of outcome has hitherto proved very difficult.

Frequency of blood glucose monitoring in relation to glycaemic control: observational study with diabetes database.

Abstract Objectives: To investigate patterns of self monitoring of blood glucose concentration in diabetic patients who use insulin and to determine whether frequency of self monitoring is related to glycaemic control. Setting: Diabetes database, Tayside, Scotland. Subjects: Patients resident in Tayside in 1993-5 who were using insulin and were registered on the database and diagnosed with insulin dependent (type 1) or non-insulin dependent (type 2) diabetes before 1993. Main outcome measures: Number of glucose monitoring reagent strips dispensed (reagent strip uptake) derived from records of prescriptions. First recorded haemoglobin A1c concentration in the study period, and reagent strips dispensed in the previous 6 months. Results: Among 807 patients with type 1 diabetes, 128 (16%) did not redeem any prescriptions for glucose monitoring reagent strips in the 3 year study period. Only 161 (20%) redeemed prescriptions for enough reagent strips to test glucose daily. The corresponding figures for the 790 patients with type 2 diabetes who used insulin were 162 (21%; no strips) and 131 (17%; daily tests). Reagent strip uptake was influenced both by age and by deprivation category. There was a direct relation between uptake and glycaemic control for 258 patients (with recorded haemoglobin A1c concentrations) with type 1 diabetes. In a linear regression model the decrease in haemoglobin A1c concentration for every extra 180 reagent strips dispensed was 0.7%. For the 290 patients with type 2 diabetes who used insulin there was no such relation. Conclusions: Self monitoring of blood glucose concentration is associated with improved glycaemic control in patients with type 1 diabetes. Regular self monitoring in patients with type 1 and type 2 diabetes is uncommon. Key messages Several studies have indicated the importance of self monitoring of blood glucose concentration for prevention of complications in patients with diabetes Uptake of reagent strips for self monitoring of blood glucose among diabetic patients who used insulin was low, with only 20% of patients with type 1 diabetes and 17% of those with type 2 diabetes obtaining enough strips to test blood glucose concentration once daily Reagent strip uptake depends on characteristics such as age and social deprivation category, and patient groups with low uptake should be identified and targeted There was a direct association between strip uptake in the previous 6 months and glycaemic control in patients with type 1 diabetes but not in those with type 2 diabetes

Towards measurement of outcome for patients with varicose veins.

OBJECTIVE--To develop a valid and reliable outcome measure for patients with varicose veins. DESIGN--Postal questionnaire survey of patients with varicose veins. SETTING--Surgical outpatient departments and training general practices in Grampian region. SUBJECTS--373 patients, 287 of whom had just been referred to hospital for their varicose veins and 86 who had just consulted a general practitioner for this condition and, for comparison, a random sample of 900 members of the general population. MAIN MEASURES--Content validity, internal consistency, and criterion validity. RESULTS--281(76%) patients (mean age 45.8; 76% female) and 542(60%) of the general population (mean age 47.9; 54% female) responded. The questionnaire had good internal consistency as measured by item-total correlations. Factor analysis identified four important health factors: pain and dysfunction, cosmetic appearance, extent of varicosity and complications. The validity of the questionnaire was demonstrated by a high correlation with the SF-36 health profile, which is a general measure of patients health. The perceived health of patients with varicose veins, as measured by the SF-36, was significantly lower than that of the sample of the general population adjusted for age and a lower proportion of women. CONCLUSION--A clinically derived questionnaire can provide a valid and reliable tool to assess the perceived health of patients with varicose veins. IMPLICATIONS--The questionnaire may be used to justify surgical treatment of varicose veins.

Developing a valid and reliable measure of health outcome for patients with low back pain.

Objective The author developed and validated a measure of health outcome for patients with low back pain. Results A questionnaire was developed incorporating the type of questions asked when taking a clinical history. After testing on a sample of 568 patients, three questions were discarded from the questionnaire. The final questionnaire was found to be reliable and valid in the sense that patients scores correlated highly with their scores on a general health profile and with GP perceptions of severity. Healty status in patients with low back pain was significantly impaired when compared with the general population. Conclusion A clinically based questionnaire, together with a general measure of health, can provide a valid and reliable package for the routine assessment of perceived health in patients with low back pain.

SF 36 health survey questionnaire: II. Responsiveness to changes in health status in four common clinical conditions.

OBJECTIVE--To assess the responsiveness of the SF 36 health survey questionnaire to changes in health status over time for four common clinical conditions. DESIGN--Postal questionnaires at baseline and after one years follow up, with two reminders at two week intervals if necessary. SETTING--Clinics and four training general practices in Grampian region in the north east of Scotland. PATIENTS--More than 1,700 patients aged 16 to 86 years with one of four conditions: low back pain, menorrhagia, suspected peptic ulcer, and varicose veins; and a random sample of 900 members of the local general population for comparison. MAIN MEASURES--A transition question measuring change in health and the eight scales of the SF 36 health survey questionnaire; standardised response means (mean change in score for a scale divided by the standard deviation of the change in scores) used to quantify the instruments responsiveness to changes in perceived health status, and comparison of patient scores at baseline and follow up with those of the general population. RESULTS--The response rate exceeded 75% in a patient population. Changes across the SF 36 questionnaire were associated with self reported changes in health, as measured by the transition question. The questionnaire showed significant improvements in health status for all four clinical conditions, whether in referred or non-referred patients. For patients with suspected peptic ulcer and varicose veins the SF 36 profiles at one year approximate to the general population. CONCLUSIONS--These results provide the first evidence of the responsiveness of the SF 36 questionnaire to changes in perceived health status in a patient population in the United Kingdom.

Patient centred assessment of quality of life for patients with four common conditions.

OBJECTIVES: To assess the reliability, validity, and responsiveness of a new quality of life measure, the patient generated index (PGI) of quality of life, in patients with four common clinical conditions. DESIGN: Prospective one year follow up study. SETTING: Outpatient departments and four general practices in Grampian, Scotland. SUBJECTS: 1746 patients consulting a general practitioner in one of four practices, or referred to outpatients from all Grampian practices over a four month period, with low back pain, menorrhagia, suspected peptic ulcer, and varicose veins. MAIN OUTCOME MEASURES: Postal questionnaire including the PGI, SF-36 health survey, and clinically derived condition specific measures of disease severity. RESULTS: Test-retest reliability was satisfactory for group comparisons (intraclass correlation coefficient 0.65). Validity was confirmed by the observed association of the PGI with the SF-36, condition specific instruments, and sociodemographic variables. For low back pain, the PGI and the SF-36 pain scale were found to be most responsive to clinical change. For patients with menorrhagia and suspected peptic ulcer, only the condition specific instruments detected larger changes than the PGI. CONCLUSIONS: It is possible to develop a patient generated index of quality of life that not only assesses the extent to which patients expectations are matched by reality but also satisfies criteria of reliability and responsiveness to change. Further work is required to make the PGI more acceptable and meaningful to patients, but it is believed that it offers an exciting new approach to the evaluation of medical care.

SF 36 health survey questionnaire: I. Reliability in two patient based studies.

OBJECTIVE--To assess the reliability of the SF 36 health survey questionnaire in two patient populations. DESIGN--Postal questionnaire followed up, if necessary, by two reminders at two week intervals. Retest questionnaires were administered postally at two weeks in the first study and at one week in the second study. SETTING--Outpatient clinics and four training general practices in Grampian region in the north east of Scotland (study 1); a gastroenterology outpatient clinic in Aberdeen Royal Hospitals Trust (study 2). PATIENTS--1787 patients presenting with one of four conditions: low back pain, menorrhagia, suspected peptic ulcer, and varicose veins and identified between March and June 1991 (study 1) and 573 patients attending a gastroenterology clinic in April 1993. MAIN MEASURES--Assessment of internal consistency reliability with Cronbachs alpha coefficient and of test-retest reliability with the Pearson correlation coefficient and confidence interval analysis. RESULTS--In study 1, 1317 of 1746 (75.4%) correctly identified patients entered the study and in study 2, 549 of 573 (95.8%). Both methods of assessing reliability produced similar results for most of the SF 36 scales. The most conservative estimates of reliability gave 95% confidence intervals for an individual patients score difference ranging from -19 to 19 for the scales measuring physical functioning and general health perceptions, to -65.7 to 65.7 for the scale measuring role limitations attributable to emotional problems. In a controlled clinical trial with sample sizes of 65 patients in each group, statistically significant differences of 20 points can be detected on all eight SF 36 scales. CONCLUSIONS--All eight scales of the SF 36 questionnaire show high reliability when used to monitor health in groups of patients, and at least four scales possess adequate reliability for use in managing individual patients. Further studies are required to test the feasibility of implementing the SF 36 and other outcome measures in routine clinical practice within the health service.

Using economics to set pragmatic and ethical priorities

Doctors and managers have to make tough decisions about what services to provide from their budgets. Economic approaches can help, but they also need to take into account the practical and ethical challenges faced by healthcare professionals

Programme budgeting and marginal analysis: bridging the divide between doctors and managers

Recent NHS reforms give doctors increased responsibility for efficient and fair use of resources. Programme budgeting and marginal analysis is one way to ensure the views of all stakeholders are properly represented nnTensions between doctors and managers and the differences between medical and managerial cultures have existed since the earliest provision of organised health care.1 In a resource allocation context, doctors are caricatured as taking the role of patient advocate while managers take the corporate, strategic view. Delivery of efficient (and in the case of the NHS, equitable) health care requires doctors to take responsibility for resources and to consider the needs of populations while managers need to become more outcome and patient centred. One economic approach, called programme budgeting and marginal analysis, has the potential to align the goals of doctors and managers and create common ground between them. We describe how the approach works and why it should be more widely used.nnProgramme budgeting and marginal analysis is an approach to commissioning and redesign of services that can accommodate both medical and managerial cultures and the widest constituency of professional, patient, and public values within a single decision making framework. It allows for the complexities of health care while adhering to the two key economic concepts of opportunity cost and the margin. When having to make choices within limited resources, certain opportunities will be taken up while others must be forgone. The benefits associated with forgone opportunities are opportunity costs. Thus, we need to know the costs and benefits of various healthcare activities, and this is best examined at the margin—that is, the benefit gained from an extra unit of resources or benefit lost from having one unit less. If the marginal benefit per pound spent from programme A is greater than that for B, resources should …