Inequalities in access to knee joint replacements for people in need.

OBJECTIVES: To quantify the effects of socioeconomic deprivation and rurality on evidence of need for total knee joint replacement and the use of health services, after adjusting for age and sex. METHODS: A random stratified sample of 15 000 people aged > or =65 years taken from central age/sex registers for the geographical areas covered by the previous Sheffield and Wiltshire Health Authorities. A self completion validated questionnaire was then mailed directly to subjects to assess need for knee joint replacement surgery and whether general practice and hospital services were being used. Subjects were followed up for 18 months to evaluate access to surgery. RESULTS: The response rate was 78% after three mailings. In those aged 65 years and over (with and without comorbidity), the proportion with no comorbid factors and in need of knee replacement was 5.1%; the rate of need among subjects without comorbidity was 7.9%. There were inequalities in health and access to health related to age, sex, geography, and deprivation but not rurality. People who were more deprived had greater need. Older and deprived people were less likely to access health services. Only 6.4% of eligible people received knee replacement surgery after 18 months of follow up. CONCLUSIONS: There is an important unmet need in older people, with significant age, sex, geographical, and deprivation inequalities in levels of need and access to services. The use of waiting list numbers as a performance indicator is perverse for this procedure. There is urgent need to expand orthopaedic services and training.

Inequalities in accessing hip joint replacement for people in need.

OBJECTIVES: To quantify the effects of rurality and socio-economic disadvantage on prior evidence of need for total hip joint replacement and use of health services after adjusting for age and gender. DESIGN: Self-completion validated questionnaire mailed directly to subjects. SETTINGS: Geographical areas covered by Wiltshire and Sheffield Health Authorities in England. PARTICIPANTS: Random stratified sample of 15,000 aged 65 years and over taken from the central age-sex registers. MAIN OUTCOME MEASURE: Prior need for hip joint replacement surgery and whether general practice and hospital services were being used as assessed by the questionnaire. RESULTS: The response rate was 78% after three mailings. Prevalence of need for total hip replacement in the over 64s was 3.4% (95% confidence interval is 3.0% to 3.8%) and in those without co-morbidity 5.4% (95% confidence interval is 4.8% to 6.0%). There were inequalities demonstrated due to age, geography, and deprivation, but not rurality in accessing general practice and hospital services. People who were poor had more need. Older people in need were less likely to be accessing health services. CONCLUSIONS: There is an important unmet need for hip joint replacement in older people with marked inequalities in levels of need and use of services. The use of numbers of people waiting as a performance indicator is perverse for this procedure. We have urgently to expand orthopaedic services and the training of orthopaedic surgeons in England.

The SF36 as an outcome measure of services for end stage renal failure.

OBJECTIVE: To evaluate the use of the short form 36 (SF36) as a measure of health related quality of life of patients with end stage renal failure, document the results, and investigate factors, including mode of treatment, which may influence it. DESIGN: Cross sectional survey of patients with end stage renal failure, with the standard United Kingdom version of the SF36 supplemented by specific questions for end stage renal failure. SETTING: A teaching hospital renal unit. SUBJECTS AND METHODS: 660 patients treated at the Sheffield Kidney Institute by haemodialysis, peritoneal dialysis, and transplantation. Internal consistency, percentage of maximal or minimal responses, SF36 scores, effect sizes, correlations between independent predictor variables and individual dimension scores of the SF36. Multiple regression analysis of the SF36 scores for the physical functioning, vitality, and mental health dimensions against treatment, age, risk (comorbidity) score, and other independent variables. RESULTS: A high response rate was achieved. Internal consistency was good. There were no floor or ceiling effects other than for the two "role" dimensions. Overall health related quality of life was poor compared with the general population. Having a functioning transplant was a significant predictor of higher score in the three dimensions (physical functioning, vitality, and mental health) for which multiple regression models were constructed. Age, sex, comorbidity, duration of treatment, level of social and emotional support, household numbers, and hospital dialysis were also (variably) significant predictors. CONCLUSIONS: The SF36 is a practical and consistent questionnaire in this context, and there is evidence to support its construct validity. Overall the health related quality of life of these patients is poor, although transplantation is associated with higher scores independently of the effect of age and comorbidity. Age, comorbidity, and sex are also predictive of the scores attained in the three dimensions studied. Further studies are required to ascertain whether altering those predictor variables which are under the influence of professional carers is associated with changes in health related quality of life, and thus confirm the value of this outcome as a measure of quality of care.

Lipid-lowering for prevention of coronary heart disease: what policy now?

1. Recent outcome trials suggest that lipid-lowering with 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors is justifiable on risk-benefit grounds in subjects with serum cholesterol > 5.5 mmol/l who have coronary heart disease, other forms of atherosclerotic vascular disease, or who are free of vascular disease but have a risk of major coronary events > or = 1.5% per year. Choice of an appropriate treatment policy will require (i) knowledge of the proportion of the population who will need treatment for secondary prevention, and (ii) targeting of treatment for primary prevention at a specified absolute risk of coronary heart disease events. Selection of an appropriate coronary heart disease risk for primary prevention requires consideration of the number needed to be treated to prevent one coronary heart disease event, the proportion of the population requiring treatment, the cost-effectiveness of treatment and the total cost of treatment. 2. In a random stratified sample of subjects aged 35-69 years from the Health Survey for England 1993 we first examined the prevalence of subjects with cardiovascular disease and serum cholesterol > 5.5 mmol/l who may be candidates for secondary prevention. In those free of cardiovascular disease we then examined the prevalence of subjects with serum cholesterol > 5.5 mmol/l who had three different levels of coronary heart disease risk: coronary heart disease event rates of 4.5% per year, 3.0% per year and 1.5% per year. These subjects may be candidates for primary prevention depending on the treatment policy selected. 3. For secondary prevention, 4.8% (95% confidence interval 4.3-5.3) of the U.K. population aged 35-69 years might be candidates for 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor treatment, comprising 2.4% (2.0 to 2.7) with a history of myocardial infarction, 1.9% (1.6 to 2.2) with angina and 0.5% (0.3-0.7) with a history of stroke--all with total cholesterol > 5.5 mmol/l. The prevalence of these diagnoses with total cholesterol > 5.5 mmol/l increased with age, from 1.5% at age 35-39 years to 16.2% at age 65-69 years in men, and from 0.2% at age 35-39 years to 10.0% at age 65-69 years in women. Approximately 13 people would need treatment for 5 years to prevent one coronary event, at a cost of 36,000 pounds per event prevented. The number needing treatment for secondary prevention would increase substantially if treatment was extended to patients above 70 years of age or to those with serum cholesterol < or = 5.5 mmol/l. 4. Primary prevention aimed at a coronary event risk of 4.5% per year would lead to treatment of only 0.3% (0.2-0.4) of those aged 35-69 years, and those treated would be predominantly older men with additional risk factors for coronary heart disease. The number needed to be treated and cost per coronary event prevented would be similar to those for secondary prevention. 5. Primary prevention targeted at subjects with a coronary event rate of 3.0% per year would entail treating 3.4% (3.0-3.9) of all those aged 35-69 years. At this level of risk, 20 people would need treatment for 5 years to prevent one coronary event, at a cost of 55,000 pounds per event prevented. 6. Primary prevention aimed at a coronary event rate of 1.5% per year would entail treating 19.6% (18.7-20.6) of all subjects aged 35-69 years, and about 80% of men aged 60-69 years for primary or secondary prevention. At this level of risk, 40 people would need treatment for 5 years to prevent one event, at a cost of 111,000 pounds per event saved. 7. Guidelines for 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor treatment should take into account the considerable workload and financial resources needed to implement secondary prevention of coronary heart disease, the accepted first priority. For primary prevention they need to consider the number needed to be treated to prevent one event, the number of subjects needing treatment, the cost-effectiveness of treatment and

Is use of hospital services a proxy for morbidity? A small area comparison of the prevalence of arthritis, depression, dyspepsia, obesity, and respiratory disease with inpatient admission rates for these disorders in England.

OBJECTIVES: To examine the relationship between specific types of morbidity, measured by validated survey questions, and hospital service use and mortality to see if the latter two could act as a proxy in health needs assessment, health service planning, and resource allocation in a typical health district. DESIGN: A postal questionnaire was used to provide information about depression, digestive disorders, musculo-skeletal disorders, obesity, respiratory disease, and hip and knee pain. The questions were from survey instruments that have been widely used to derive information about these conditions. The relationships between the prevalence of these specific types of morbidity and appropriate admission and mortality rates were explored using linear regression and Pearson correlation analysis. SETTING: The population of Rotherham health district, England. SUBJECTS: A simple random sample of the residents of each of the 22 electoral wards in Rotherham health district. RESULTS: Responses were obtained from 78% of the 5000 sampled (82% after excluding people who had moved house or died). Significant, positive correlations were found between the prevalence of respiratory disease and the hospital admission and mortality rates for respiratory problems (r = 0.68, p < 0.01 and r = 0.54, p < 0.01) and the prevalence of depression and the admission rate for depression (r = 0.52, p < 0.05). No such relations were found for digestive disease, musculo-skeletal disease, and obesity. For the conditions examined here, hospital service use was a more useful measure than mortality. CONCLUSIONS: Only two diseases (respiratory disease and depression) out of the seven diseases or procedures investigated showed a positive correlation between hospital admission and disease prevalence. But even for these two, the correlations explained less than 50% of the variance. Caution must be exercised when hospital service use is being considered as a proxy for morbidity.

Local confidential inquiry into avoidable factors in deaths from stroke and hypertensive disease.

OBJECTIVE: To audit avoidable deaths from stroke and hypertensive disease. DESIGN: Details of care before death were obtained from general practitioners and other doctors, anonymised, and assessed by two experts against agreed minimum standards of good practice for detecting and managing hypertension. SETTING: Health authority with population of 250,000. SUBJECTS: All patients under 75 years who died of stroke, hypertensive disease, or hypertension related causes during November 1990 to October 1991. MAIN OUTCOME MEASURES: Presence of important avoidable factors and departures from minimum standards of good practice. RESULTS: Adequate information was obtained for 88% (123/139) of eligible cases. Agreement between the assessors was mostly satisfactory. 29% (36/123, 95% confidence interval 21% to 37%) of all cases and 44% (36/81, 34% to 55%) of those with definite hypertension had avoidable factors that may have contributed to death. These were most commonly failures of follow up and continuing smoking. Assessment against standards of minimum good practice showed that care was inadequate but not necessarily deemed to have contributed to death, in a large proportion of patients with definite hypertension. Common shortcomings were inadequate follow up, clinical investigation, and recording of smoking and other relevant risk behaviours. CONCLUSIONS: This method of audit can identify shortcomings in care of patients dying of hypertension related disease.

Are deprivation indicators a proxy for morbidity? A comparison of the prevalence of arthritis, depression, dyspepsia, obesity and respiratory symptoms with unemployment rates and Jarman scores.

The aim of the study was to examine the relationship between specific areas of morbidity measured using validated survey questions and deprivation indicators to see if the latter could act as a proxy in health needs assessment, health service planning and resource allocation in a typical health authority. A postal questionnaire was used to provide information about arthritis, depression, dyspepsia, obesity and respiratory symptoms in a simple random sample from the study population. The questions were from survey instruments that have been widely used to derive information about these conditions. The relationships between the prevalence of these specific areas of morbidity and both unemployment and the Jarman Underprivileged Areas Score were explored. Spearman's rank correlation coefficients were calculated and compared for each combination of measures. The study population was a random sample of the residents of each of the 22 electoral wards in Rotherham Health Authority. Responses were obtained from 82 per cent of the 5000 sampled. Although all morbidity measures showed positive correlations with both Jarman score and unemployment, some, notably those relating to respiratory disease and depression, were much more strongly correlated than others, such as obesity. There was no difference between unemployment and Jarman score in respect of the magnitude of the correlation coefficients. In conclusion, for some, but not all, conditions socio-economic measures are a good proxy for morbidity. Unemployment is just as useful a proxy as the Jarman score.

Limitations of the OPCS congenital malformation notification system illustrated by examination of congenital malformations of the cardiovascular system in districts within the Trent Region.

Data are presented from OPCS notification statistics and other sources on rates of congenital cardiovascular malformations in the Trent Health Region and in its constituent Districts. While Trent in general, and some of its districts in particular, show high notification rates, other data sources suggest that the underlying malformation rate may not be raised compared with that seen nationally. Reasons for this discrepancy are discussed and the OPCS notification system is compared with that in Scotland.

The introduction of a computerized system for notification and improved analysis of infectious diseases in Sheffield.

In 1989 the manual system of recording and analysing notifications of infectious disease in Sheffield was replaced by a computerized system based on the Epi Info software package. An analysis of the costs and benefits of this change shows that there has been a one-off cost of 780-930 h spent in developing the system. Offset against this is a continuing saving of time of around 400 h per annum. Other benefits which are harder to measure are enumerated and discussed. Costs of computer hardware and software are not substantial in comparison with the savings in staff time.

Comparison of the efficiencies of true blue and diamidino yellow as retrograde tracers in the peripheral motor system.

The abilities of the fluorescent retrograde tracers true blue and diamidino yellow to label motor neurons of the rat sciatic nerve were compared quantitatively. Following injection of a mixture of the 2 tracers into the sciatic nerve, diamidino yellow was found only in double-labelled neurons, while 28% of labelled neurons contained true blue alone. The relative labelling efficiency of diamidino yellow, at only 72%, was significantly lower than that of true blue. When the tracers were injected separately a difference in the labelling efficiency was still observed but, in addition, there were significantly fewer diamidino yellow-labelled neurons than when a mixture had been injected. This suggests that the presence of true blue in the mixture had enhanced the uptake, transport or visualisation of diamidino yellow. When a mixture of true blue and diamidino yellow was applied to the cut sciatic nerve, the relative labelling efficiency of diamidino yellow (77%) was again found to be lower than that of true blue, but positive identification of diamidino yellow-labelled cells was hampered by chromatolytic changes in the cell bodies. Injection of the tracer mixture into the gastrocnemius muscle resulted in a diamidino yellow labelling efficiency (36%) significantly lower than that obtained with either nerve injection or nerve dipping. Thus, compared to true blue, diamidino yellow was either less capable of reaching the motor endplates within the muscle, or it was taken up less efficiently by axon terminals than by the axons themselves.

Fluorometric comparisons of the retrograde axonal transport of true blue and diamidino yellow from the rat caudate-putamen.

The retrograde tracers true blue and diamidino yellow were injected into the caudate-putamen of adult rats which were allowed to survive for periods of 12 to 480 h after these injections. The retrograde axonal transport of these tracers was assessed by microphotometric measurement of the intensity of fluorescence in labelled neurones in the following three different sources of afferents to the caudate-putamen: the substantia nigra pars compacta; the parafascicular nucleus; and the dorsal raphe nucleus. It took respectively 12, 24 and 48 h for neurones in the substantia nigra, parafascicular nucleus and dorsal raphe nucleus to become retrogradely labelled. The average fluorescent intensity was greatest after 96-168 h but this highest value, and the subsequent decline, in fluorescence varied considerably between different tracers and different pathways. Neither axonal length nor neuronal activity correlate well with dynamics of build up and decline in fluorescence, but axonal collateralisation and diffuseness of terminals are associated with slower accumulation and more rapid removal of the tracers. Some neurones labelled with true blue retain their fluorescence better than those labelled with diamidino yellow but these differences are overshadowed by differences between different pathways in this respect.

Cerebellar afferents in early postnatal rats: a retrograde fluorescence study.

The development of afferent projections to the cerebellum was studied by making small (20 nl) injections of True blue into the cerebella of neonatal rats under general anaesthesia. Neurones in all main precerebellar nuclei were labelled even in rats less than one day old. With the exception of the disappearance of small numbers of ipsilateral olivocerebellar projections, no qualitative differences were seen after injections in animals one or two weeks older.

Accurate counting of neurons in frozen sections: some necessary precautions.

In 30 microns frozen sections of rat midbrain the retrograde axonal transport of diamidino yellow, a fluorescent tracer, was used to demonstrate a population of neurons in the substantia nigra. However, when visualisation was carried out using the routine Nissl method a significant proportion of neurons failed to stain. As the presence of the retrograde tracer did not affect Nissl staining of such cells, such incomplete staining, with consequent underestimation of neuronal populations, is probably a common error in similar material. Further investigation revealed that the proportion of such unstained neurons was greater when the staining time was short, when stain concentration was low, or when section thickness was increased. Some stains were worse in this respect than others. Cresyl fast violet resulted in the highest proportion of unstained neurons, thionin resulted in the lowest proportion. It was concluded that the rate of diffusion of the stain into the section was the main factor limiting the staining of neurons present. Staining with pure thionin at 0.1% concentration for at least 3 minutes and with sections no thicker than 30 microns is one regime which would avoid this problem.

Cerebellar afferents from the lateral reticular nucleus in the rat.

The projection from the lateral reticular nucleus to the cerebellum was examined using the retrograde fluorescent double labelling method in the rat. A quantitative analysis of the extent of axonal branching and of nucleotopic (topographic) organization in this projection was carried out. It was shown that lateral reticular nucleus neurons show axonal branching both within and between parasagittal zones of the cerebellar cortex, but that branching within zones is more common. Neurons projecting to different zones were found to be significantly spatially separated, but those projecting to different sites within the same zone were intermingled. Thus a limited degree of nucleotopic organization was found. The results are discussed in relation to the parasagittal zonation in the olivocerebellar projection.

A temperature controlled chamber to allow observation and measurement of uptake of fluorochromes into live cells.

A temperature controlled cell chamber is described which permits phase-contrast and fluorescence microscopy of living cells. It is shown how the cellular uptake of fluorochromes can be investigated both photographically and photometrically. Some sample results are presented for the uptake of Evans Blue.

An ipsilateral olivocerebellar pathway in the normal neonatal rat demonstrated by the retrograde transport of true blue.

Neonatal rats, aged less than 24 h, were anaesthetised and 25 nl of 2% True blue was injected into the lateral part of the left cerebellar hemisphere. After 48-60 h, the brains were fixed by perfusion and 30 micron thick frozen sections were prepared of the brainstem and cerebellum. Only animals in which the injection sites were clearly unilateral were studied. In the contralateral inferior olive numerous True blue-labelled neurones were seen. In addition, the ipsilateral olive in all animals contained True blue-labelled neurones. This demonstrates that in these neonatal animals there is an ipsilateral olivocerebellar pathway.

Histochemical implications of the chemical and biological properties of SITS and some related compounds.

Since commercial samples of the fluorochrome SITS (sodium 4-acetamido-4'-isothiocyanatostilbene-2,2'disulphonate) are of varied, and often of uncertain, composition, the synthesis of SITS has been repeated. The identities of SITS and certain of its precursors and derivatives have been established using modern spectroscopic methods (IR, 1H and 13C NMR), as well as microanalysis. When pure SITS underwent hydrolysis at room temperature the products were amines, not the expected thioureas. This suggests that SITS, contrary to previous expectations, will not bind covalently to proteins, whether immunoglobulins or membrane constituents. Again contrary to earlier statements, pure SITS is not retrogradely transported in neuronal axons. The transported material is a red-orange impurity which arises very occasionally during the preparation of SITS. A possible structure for this red-orange compound is proposed: namely a dimeric azo or azoxy condensation product. Comparison of pure SITS with commercial samples indicated that the latter were extremely varied in composition, with SITS contents varying from high to trivial.