Incidence of symptoms in previously symptom-free impacted lower third molars assessed in general dental practice

AIM

To determine the potential of a pathology-free impacted lower third molar to cause symptoms within a year and whether these symptoms can be linked to clinical characteristics, lifestyle or socio-demographic status.

DESIGN

One-year prospective cohort study of patients registered in general dental practice in Scotland with at least one asymptomatic impacted lower third molar.

METHODS

All general dental practices with panoramic radiography facilities in Tayside, Fife and Greater Glasgow (Scotland, UK) were invited to participate in the study. Orthopantomographs taken between 1995 and 2002 were reviewed and eligible patients were contacted and invited to participate. Patients were assessed in their own dental surgery by the same research dentist. In this baseline assessment, the presence of impaction was confirmed and all patients with a previous history of symptoms and/or pathology were excluded from further analysis. Clinical characteristics such as the angulation and the degree of impaction were recorded. Patients also completed a socioeconomic questionnaire. Eligible patients were re-assessed by the same research dentist one year later when they were asked about their experience of symptoms within the past year. Information was cross-referenced with patients' dental records.

RESULTS

A total of 613 patients attended the baseline appointment. Of those, 30 (4.89%) had a history of symptoms and were excluded from the study, leaving 583 (95.10%) eligible patients. From those, 421 (69%) patients with a total of 676 lower third molars were examined one year later. 22.67% of all vertically impacted teeth examined had developed symptoms, along with 13.15% of all mesially impacted, 30.69% of all distally impacted and 6.45% of all horizontal third molars. This association was statistically significant (p < or =0.001). 23.05% of all partially erupted teeth and a surprising 10.49% of all unerupted teeth were associated with symptoms during the study period. This association was also significant (p < or =0.001). There was also a statistically significant inverse association between the development of symptoms and age (p = 0.0028).

CONCLUSIONS

The predictability that an impacted lower third molar will develop symptoms in future remains unclear. However, some clinical characteristics such as the angulation, the degree of impaction and the patient's age could be useful in predicting the likelihood of future symptomatology.

Glaucoma incidence in an unselected cohort of diabetic patients: is diabetes mellitus a risk factor for glaucoma? DARTS/MEMO collaboration. Diabetes Audit and Research in Tayside Study. Medicines Monitoring Unit

AIMS

To evaluate whether diabetes mellitus is a risk factor for the development of primary open angle glaucoma or ocular hypertension (OHT).

METHODS

A historical cohort study of an unselected population comprising all residents of the Tayside region of Scotland was performed using record linkage techniques followed by case note review. Ascertainment of prevalent diabetes was achieved using the Diabetes Audit and Research in Tayside Study (DARTS) validated regional diabetes register. Glaucoma and treated OHT were defined by encashment of community prescriptions and the statutory surgical procedure coding database.

RESULTS

The study population comprised 6631 diabetic subjects and 166 144 non-diabetic subjects aged >40 years without glaucoma or OHT at study entry. 65 patients with diabetes and 958 without diabetes were identified as new cases of glaucoma or treated OHT during the 24 month study period, yielding a standardised morbidity ratio of 127 (95% CI, 96-158). Case note review demonstrated non-differential misclassification of prevalent glaucoma and OHT as incident disease (diabetic cohort 20%, non-diabetic cohort 24%; p=0.56) primarily as a result of non-compliance in medically treated disease. Removing misclassified cases and adjusting for age yielded an incidence of primary open angle glaucoma in diabetes of 1.1/1000 patient years (95% CI, 0.89-1. 31) compared to 0.7/1000 patient years (95% CI, 0.54-0.86) in the non-diabetic cohort; RR 1.57 (95% CI, 0.99-2.48).

CONCLUSIONS

This study failed to confirm an association between diabetes mellitus and primary open angle glaucoma and ocular hypertension. A non-significant increase in diagnosed and treated disease in the diabetic population was observed, but evidence was also found that detection bias contributes to this association.

Assessing health outcomes after extraction of third molars: the postoperative symptom severity (PoSSe) scale

A postoperative symptom severity (PoSSe) scale was devised from questions commonly used in the clinical assessment of patients who have had third molars extracted, and divided into subscales corresponding to seven main adverse effects that had been identified in a previous study. Ninety-seven patients completed the 15-item questionnaire at one week, and 71 patients at four weeks, after extraction of impacted third molars. After statistical testing, four items were discarded and the final PoSSe scale achieved a high level of internal reliability. Patients' PoSSe scores were highly correlated with scales that measured six distinct health dimensions. The level of social functioning, together with the number of impacted teeth and number of painkillers taken, explained 62% of the variation in PoSSe scores between patients one week postoperatively. The PoSSe was more responsive than the Short Form 36-item Health Survey. In conclusion, we found the PoSSe Scale to be a reliable, valid and responsive measure of the severity of symptoms after extraction of third molars, and of the impact of those symptoms on patients' perceived health.

Socio-economic status, obesity and prevalence of Type 1 and Type 2 diabetes mellitus

AIMS

The influence of socio-economic status on the prevalence of Type 1 and Type 2 diabetes mellitus, and on obesity, was explored using routinely collected healthcare data for the population of Tayside, Scotland.

METHODS

Among 366,849 Tayside residents, 792 and 5,474 patients with Type 1 and Type 2 diabetes, respectively, were identified from a diabetes register. The Carstairs Score was used as a proxy for socio-economic status. This is a material deprivation measure derived from the UK census, using postcode data for four key variables. Odds ratios for diabetes prevalence, adjusted for age, were determined for each of six deprivation categories (1 - least deprived, 6/7 - most deprived). The mean body mass index (BMI) in each group was also determined, and the effect of deprivation category explored by analysis of covariance, adjusting for age and sex.

RESULTS

The prevalence of Type 2 diabetes, but not Type 1 diabetes, varied by deprivation. People in deprivation category 6 and 7 were 1.6-times (95% confidence interval 1.4-1.8) more likely to have Type 2 diabetes than those least deprived. There was no relationship between deprivation and BMI in Type 1 diabetes (P = 0.36), but there was an increase in BMI with increasing deprivation in Type 2 diabetes (P < 0.001; test of linearity P < 0.001).

CONCLUSIONS

The study confirms the relationship between deprivation and the prevalence of Type 2 diabetes. There are more obese, diabetic patients in deprived areas. They require more targeted resources and more primary prevention.

Impact of type 1 and type 2 diabetes on patterns and costs of drug prescribing: a population-based study

OBJECTIVE

Utilization and costs of prescription drugs were investigated in diabetic and nondiabetic patients.

RESEARCH DESIGN AND METHODS

The study was carried out in Tayside, Scotland, U.K. A validated population-based diabetes register was used to identify patients with type 1 and type 2 diabetes, and a database of all prescriptions dispensed in the community was used to investigate drug utilization in 1995.

RESULTS

In a population of 406,526, there were 974 (0.2%) with type 1 diabetes and 6,869 (1.7%) with type 2 diabetes. The mean dispensed prescribing rates for all drugs (excluding antidiabetic medication) were higher across all age-groups for diabetic patients. After adjusting for age, patients with type 1 diabetes were 2.07 times (95% CI 2.03-2.11) more likely and patients with type 2 diabetes were 1.70 times (1.69-1.71) more likely to be dispensed a drug item than people without diabetes. This likelihood was increased in every drug category, even those not directly related to diabetes, and the proportion and cost of drug items dispensed to diabetic patients was therefore higher than expected given the prevalence of diabetes. Upon projecting these results to the U.K. population, it was discovered that nearly 8% of the U.K. drug budget (Pound Sterling 350 million) is accounted for by patients with diabetes (90% of that by patients with type 2 diabetes).

CONCLUSIONS

This study highlights the increased usage and cost of prescription drugs in diabetes, with type 2 diabetes constituting a particular burden. It was discovered that 1.4% of drug usage in the entire population can be accounted for by the increased prescribing rate of diabetic patients compared with that of nondiabetic patients.

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

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.

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.

Quality of life following third molar removal: a patient versus professional perspective

AIMS

To identify the adverse effects of third molar surgery having the greatest impact on patients' perceived quality of life; and to compare the rankings between patients, dental practitioners (GDPs) and hospital consultants.

METHOD

Seven adverse effects were identified after interviewing 20 patients. A questionnaire was sent to 120 patients whose third molars had been removed and 121 dental surgeons (100 GDPs and 21 consultants in oral and maxillofacial surgery).

RESULTS

Response rates for patients, GDPs and consultants were 72.5%, 92% and 76.2% respectively. Patients ranked highest the effects on eating, while dental surgeons ranked 'pain' the highest. The mean rankings of consultants and patients generally showed a closer agreement, than with GDPs. However, no statistically significant differences were detected between the mean rankings of GDPs and consultants.

CONCLUSIONS

Dental surgeons' perceptions of the impact of third molar surgery on their patients' quality of life show statistically significant differences from those of patients for four of the seven parameters assessed. Clinicians should consider mentioning the effects on ability to eat when obtaining informed consent, since patients would appear to rank this an important side effect.

Comparison of the MOS short form-12 (SF12) health status questionnaire with the SF36 in patients with rheumatoid arthritis

OBJECTIVE

To compare the performance of the MOS SF12 health survey (SF12) with the SF36 in a sample of 233 patients with rheumatoid arthritis (RA) stratified by functional class.

METHODS

The SF12 and SF36 physical and mental component summary scales (PCS and MCS) were compared for test retest reliability [intra-class correlation coefficient (RC) and repeatability], construct validity and responsiveness [standardized response mean (SRM)] to self-reported change in health.

RESULTS

Overall, despite its brevity, the SF12 is comparable to the SF36 with only some loss of performance. The SF12-PCS is slightly less reliable (RC = 0.75) and responsive to improvements in health (SRM = 0.52) than the SF36-PCS (RC = 0.81; SRM = 0.61). The SF12-PCS correlates strongly with the SF36-PCS (R = 0.94), SF36 physical function subscale (R = 0.77) and modified Stanford Health Assessment Questionnaire (MHAQ) (R = 0.71), but only weakly with the SF36 mental health subscale (R = 0.22). SF12-PCS discriminated well between Steinbrocker functional classes; patients in functional classes 1-4, respectively, have SF12-PCS scores 1sigma, 2sigma, 2.4sigma and 2.7sigma below the population norm (ANOVA, F = 35.8, P < 0.000). The SF12-MCS is relatively unresponsive to reported improvement in RA (SRM = 0.31), but is reliable (RC = 0.71) and correlates well with the SF36-MCS (R = 0.71). SF12-MCS correlates more closely than the SF36-MCS with the SF36 mental health subscale (R = 0.86) and Hospital Anxiety and Depression (HAD) scale (R = 0.76). In ANOVA models, only the HAD (R2 = 57%) score contributes significantly to variance in SF12-MCS (F = 254.8; P < 0.000), but both the HAD (R2 = 24%) and MHAQ (R2 = 10%) scores contribute to variance in the SF36-MCS (F = 50.9; P < 0.000). Thus, the SF12-MCS has better construct validity for mental health than SF36-MCS in RA subjects. Missing responses to items were high amongst patients in functional class 4 (34%).

CONCLUSION

The SF12 is a reliable, valid and responsive measure of health status in the majority of RA patients, and meets standards required for comparing groups of patients. Its application in the most severely disabled subjects is uncertain.

Measuring health status in British patients with rheumatoid arthritis: reliability, validity and responsiveness of the short form 36-item health survey (SF-36)

The objective was to assess the performance of the SF-36 health survey (SF-36) in a sample of patients with rheumatoid arthritis (RA) stratified by functional class. The eight SF-36 subscales and the two summary scales (the physical and mental component scales) were assessed for test retest reliability, construct validity and responsiveness to self-reported change in health. In 233 patients with RA, the SF-36 scales were: reliable (intra-class correlation coefficients 0.76-0.93); correlated with American College of Rheumatology (ACR) core disease activity measures [Spearman r = -0.12 (erythrocyte sedimentation rate) to -0.89 (Modified Health Assessment Questionnaire)]; and responsive to improvements in health (standardized response means 0.27-0.9). The distribution of scores on four of the eight subscales (physical function, role limitations physical, role limitations emotional and social function) was clearly non-Gaussian. Very marked floor effects were noted with the physical function scale, and both ceiling and floor effects with the other three subscales. The two SF-36 physical and mental component summary scales are reliable, valid and responsive measures of health status in patients with RA. Six of the eight subscales meet standards required for comparing groups of patients, and the physical function and general health scales may be suitable for monitoring individuals. The two scales measuring role limitations have poor measurement characteristics. The SF-36 pain and physical function scales may be suitable for use as patient self-assessed measures of pain and physical function within the ACR core disease activity set.

Determining priorities for change in primary care: the value of practice-based needs assessment

BACKGROUND

Primary care is being expected to expand the range of services it provides, and to take on many of the tasks traditionally provided in secondary care. At the same time, general practitioners (GPs) will become increasingly responsible for assessing their patients' health care needs and commissioning care from other providers. This article describes an approach taken in one general practice to meet these difficult challenges.

AIM

To examine whether information on health and health care needs, when used as the basis for a priority setting exercise, can provide a useful first step in planning primary care provision within a practice.

METHOD

A three-stage process of information-gathering from a number of sources, including continuous data recording of patient contacts and a postal survey of all adults registered with the practice, identification of key findings and discussion of associated issues, and priority setting of proposals for practice development using the nominal group technique.

RESULTS

Continuous data recording of patient contacts with GPs and the practice nurse provided data on 4489 GP contacts with 2027 patients, 1000 district nurse contacts with 101 patients, and 361 health visitor contacts with 172 clients. More than 70% of patient records had been computerized, with 600 diagnostic READ codes identified and 11,500 separate entries made. The socioeconomic and health survey questionnaire achieved an 84% response rate. Following the priority-setting exercise, 28 proposed practice developments were identified. These were reduced to a final list of eight.

CONCLUSION

A comprehensive method of practice-based needs assessment, when used as the basis for some form of priority setting, has great potential in helping to plan primary care services within a practice. The success of such initiatives will require a substantial investment of resources in primary care and fundamental changes to the way in which primary care is funded.

Measurement of quality of life in atopic dermatitis: correlation and validation of two different methods

Atopic dermatitis is a chronic relapsing condition that can have considerable effects on the lives of sufferers. It is apparent that good, valid measures of life quality are necessary for quantifying the patients' perspective of the severity of their disease and the Dermatology Life Quality Index is often employed in clinical research. In a community study of atopic dermatitis we have assessed disability using the Dermatology Life Quality Index and the Patient Generated Index and compared the results from both indices. The results were significantly correlated and reflected the range of disability in patients in the community. Some items of the Dermatology Life Quality Index were not relevant for atopic dermatitis patients in the community and others, including swimming and sleep loss, were often cited in the Patient Generated Index but are not included in the Dermatology Life Quality Index. The Patient Generated Index is a novel, flexible approach to quality of life measurement that may be suitable for reflecting the wide variety of disability that is experienced by dermatological patients.

Economics, public health and health care purchasing: the Tayside experience of programme budgeting and marginal analysis

In this paper it is shown how the economics framework of programme budgeting and marginal analysis (PBMA) can be used to help formulate a purchasing strategy in health care; in this case, for child health services. The basic premise of PBMA is that to have more of some services it is necessary to have less of others. Therefore, it is important to know how resources are currently spent, what changes can be made, and what are the possible costs and benefits of such changes. Despite a lack of evidence on the effectiveness of services, PBMA provides a pragmatic purchasing framework. This framework permits consideration of national policy, local epidemiology, current spending, and the views both of parents and professionals as to how such spending can be changed.

Developing a condition-specific measure of health for patients with dyspepsia and ulcer-related symptoms

A patient-administered instrument for dyspepsia and symptoms suggestive of duodenal or gastric ulcer, based on the type of questions asked when taking a patient's history, was developed and tested using the following steps: literature reviews, devising the questions, testing the responses to the questions using factor analysis and internal consistency, assessing test-retest reliability, and validating the questionnaire by comparing patient responses to the SF-36 health survey questionnaire. The main sample consisted of 135 patients referred to an outpatient clinic with dyspepsia, and 152 patients in general practice who were not referred to a specialist. The final instrument produced a Cronbach's alpha of 0.72 and an intraclass correlation coefficient of 0.69. Patient scores on the dyspepsia questionnaire had small to moderate correlations with the SF-36 health survey, the largest correlation being with the SF-36 scale of pain. Patient scores were significantly related to general practitioner perceptions of symptom severity, family history of gastric ulcer disease, and whether the patient was referred. The questions asked in taking a clinical history from a patient with dyspepsia and other symptoms suggestive of ulcer disease can be used to construct a valid and reliable measure of the effect of dyspepsia on health.

Responsiveness of the SF-36 and a condition-specific measure of health for patients with varicose veins

Approaches to measuring patient perceptions of outcome for varicose veins were tested using a postal questionnaire incorporating a clinically derived specific measure of varicose veins severity and the SF-36 health survey. The questionnaire was administered to 373 patients with varicose veins, 287 of whom had been referred to hospital for their varicose veins and 86 who had just consulted a general practitioner for the condition. The response rate exceeded 75%. Test-retest reliability was assessed by mailing patients a similar questionnaire at two weeks. The validity of the two instruments was assessed by comparing patient scores to general practitioner ratings of symptom severity and complications associated with varicose veins. Standardized response means (mean change in scores divided by the standard deviation of the change in scores) were used to quantify and compare the responsiveness of the two measures. Levels of test-retest reliability, as assessed by the intraclass correlation coefficient, were acceptable and the instruments appear to have good levels of validity. Patients who were or were not admitted to hospital for surgery on their veins had significant improvements in perceived health status on both the specific measure and the SF-36. The specific measure was the most responsive to changes in health status for both patients who were admitted to hospital for surgery and those receiving alternative forms of management. These two approaches might be suitable as part of a package of outcome measures for use in clinical trials to assess the effectiveness of different interventions for varicose veins.

Assessment of patients with menorrhagia: how valid is a structured clinical history as a measure of health status?

A patient-administered questionnaire for menorrhagia based on the type of questions asked when taking a gynaecological history was developed and tested using the following steps: literature reviews, devising the questions, testing responses for internal consistency and test-retest reliability and validating the questionnaire by comparing patient's scores with their responses to the SF-36 general health measure, and with family practitioner perceptions of severity. The main sample consisted of 351 women with menorrhagia, 246 referred to gynaecology ambulatory clinics and 105 from four large training practices in North-east Scotland. Following testing, two questions were discarded from the questionnaire. The final questionnaire demonstrated a good level of reliability and the resulting patient scores correlated significantly with their scores on the scales making up the general health measure. The questions asked in taking a clinical history from a woman with menorrhagia can be used to construct a valid and reliable measure of health status. This clinical measure may be a useful guide in selection for treatment and in the assessment of patient outcome following treatment.

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 year's 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 instrument's 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.

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 Cronbach's 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 patient's 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.

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 patient's quality of life through medical care would be to "narrow the gap between a patient's 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 practitioner's 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.

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

OBJECTIVE

The authors 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. Health 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.

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.

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.

Development of indicators for quality assurance in public health medicine

OBJECTIVES

To develop structure, process, and outcome indicators within a quality rating index for audit of public health medicine.

DESIGN

Development of an audit matrix and indicator of quality through a series of group discussions with public health physicians, from which self administered weighted questionnaires were constructed by a modified Delphi technique.

SETTING

Five Scottish health boards.

SUBJECTS

Public health physicians in the five health boards.

MAIN MEASURES

Indicators of quality and a quality rating index for seven selected service categories for each of seven agreed roles of public health medicine: assessment of health and health care needs in information services, input into managerial decision making in health promotion, fostering multisectoral collaboration in environmental health services, health service research and evaluation for child services, lead responsibility for the development and/or running of screening services, and public health medicine training and staff development in communicable disease.

RESULTS

Indicators in the form of questionnaires were developed for each topic. Three types of indicator emerged: "global," "restricted," and "specific." A quality rating index for each topic was developed on the basis of the questionnaire scores. Piloting of indicators showed that they are potentially generalisable; evaluation of the system is under way across all health boards in Scotland.

CONCLUSION

Measurable indicators of quality for public health medicine can be developed.