Maximum and average urine flow rates in normal male and female populations--the Liverpool nomograms

The study of voiding in men and women has been handicapped by the lack of a normal reference range covering urinary flow rates over a wide range of voided volumes. Normal volunteers (331 males and 249 females) were studied. Each voided once into a calibrated Dantec Urodyn 1000 mictiograph. On a second occasion 282 men and 46 women voided. The maximum and average urine flow rates of the first voids in both sexes were compared with the respective voided volumes. Nomogram charts, in centile form, for both the maximum and average urine flow rates were constructed using statistical transformations of the data. Males showed a significant decline in both urinary flow rates with age, although there was no statistically significant variation in either urine flow rate with respect to first versus repeated voiding. Females showed no statistically significant variation in either urine flow rate with respect to age, parity or first versus repeated voiding. The maximum and average urine flow rates in both sexes showed an equally strong relationship to voided volume. No artificial restriction of voided volume, e.g. minimum 200 ml, appeared appropriate. These nomograms offer reference ranges for both maximum and average urinary flow rates in both sexes covering a wide range of voided volumes (15-600 ml).

Chronic musculoskeletal pain rarely presents in a single body site: results from a UK population study

OBJECTIVE

To investigate the frequency and health impact of chronic multi-site musculoskeletal pain, in a representative UK sample.

METHOD

Population postal questionnaire survey, using 16 general practices in the southeast of England, nationally representative urban/rural, ethnic and socioeconomic mix. A random selection of 4049 registered patients, aged 18 or over, were sent a questionnaire. The main outcome measures were chronic pain location, identified using a pain drawing; distress, pain intensity and disability as measured by the GHQ12 and the Chronic Pain Grade.

RESULTS

A total of 2445 patients (60%) responded to the survey (44% male, mean age 52 yrs); 45% had chronic musculoskeletal pain. Of those with chronic pain, three quarters had pain in multiple sites (two or more sites). Variables significantly predicting this were: age under 55, [odds ratio (OR) 0.5, 95% confidence interval (CI) 0.4, 0.6]; psychological distress (OR 1.8, CI at 95% 1.4, 2.2) and high pain intensity (OR 5.2, CI at 95% 4.1, 6.7). Only 33% of multi-site pain distributions conformed to the American College of Rheumatology definition of chronic widespread pain.

CONCLUSIONS

Multi-site chronic pain is more common than single-site chronic pain and is commonly associated with other problems. Indiscriminate targeting of research and care for chronic musculoskeletal pain on single sites may often be inappropriate.

Fibrosing colonopathy in cystic fibrosis: results of a case-control study

Fibrosing colonopathy was first described in cystic fibrosis (CF) children in 1994. We have done a nested case-control study to identify possible associations with this condition. A case ascertainment within the UK CF population to identify any cases that occurred between January, 1984, and April, 1994, found 14 cases, all under 14 years and confirmed by independent histopathological review. All had presented since April, 1993; 12 were boys and six had received some or all of their care in Liverpool. Each case was matched, by date of birth, with four controls from the UK CF Registry. Information was obtained about cases and controls from their case records and by a structured interview with the families. In the 12 months before surgery, there was an association between the occurrence of fibrosing colonopathy and use of high-strength pancreatic enzyme preparations. This association was dose related. Odds ratio per extra 1000 high-strength capsules was 1.45 (95% CI 1.14-1.84). For use of protease, the odds ratio per million extra units per kg was 1.55 (1.19-2.03). For usage of individual high-strength products at any time during the 12 months before surgery some differences were observed; for Creon 25000 the odds ratio was 0.38 (0.10-1.42), for Nutrizym 22 43.4 (2.51-751), and for Pancrease HL 8.4 (1.95-36.1). These last two confidence intervals are extremely wide and compatible with these two products having the same odds ratios. Laxative use was independently predictive (odds ratio 2.42 [1.20-4.94]). We conclude that there is a dose-related association between high-strength pancreatic enzyme preparations and fibrosing colonopathy.

Evidence-based medicine as Bayesian decision-making

We review two recent trends: the emergence of evidence-based medicine and the growing use of Bayesian statistics in medical applications. Evidence-based medicine requires an integrated assessment of the available evidence, and associated uncertainty, but there is also an emphasis on decision-making, for individual patients, or at other points in the health-care system. This demands consideration of the values and costs associated with potential outcomes. We argue that the natural statistical framework for evidence-based medicine is a Bayesian approach to decision-making that incorporates an integrated summary of the available evidence and associated uncertainty with assessment of utilities. We outline a practical agenda for further development.

Tutorial in biostatistics Bayesian data monitoring in clinical trials

Many clinical trials organizations use regular interim analyses to monitor the accruing results in large clinical trials. In disease areas such as cancer, where survival is usually a major outcome variable, ethical considerations may lead to a stipulated requirement for data monitoring of mortality. This monitoring has frequently taken the form of limiting interim analyses to be few in number, and specifying an extreme p-value of, for example, p < 0.001 or p < 0.01 as grounds for early termination of the trial. Group-sequential methods are also used. However, none of these approaches formally assesses the impact that the results of a clinical trial may have upon clinical practice. Thus a trial might be terminated early because of apparent treatment benefits, but might fail to influence sceptical clinicians to modify their future treatment policy. We discuss the application of Bayesian methods, including the use of uninformative, sceptical and enthusiastic priors, and demonstrate that the necessary calculations are both straightforward to perform and easy to interpret statistically and clinically. Methods are illustrated with interim analyses of a clinical trial in oesophageal cancer.

A prospective randomised controlled trial comparing the efficacy of somatostatin with injection sclerotherapy in the control of bleeding oesophageal varices

Since previous reports have suggested that somatostatin may be of value in the control of acute variceal haemorrhage, we compared its efficacy with that of injection sclerotherapy in a randomised controlled clinical trial. Eighty consecutive patients with endoscopically-proven severe variceal bleeding were randomised to injection sclerotherapy (n = 41) or somatostatin (n = 39) given as a continuous infusion of 250 micrograms/h for 5 days plus daily bolus administration of 250 micrograms. The efficacy of injection sclerotherapy and somatostatin infusion in controlling haemorrhage and preventing rebleeding (censored at 5 days), mortality (censored at 28 days) and complications was compared. The aetiology of the portal hypertension and transfusion requirements was similar between the two groups, but there were more patients with severe liver disease (Child's C) in the somatostatin group. There was no significant difference between the two treatments in the initial (p = 1.0) or overall control of bleeding (p = 0.58). Furthermore, somatostatin was as effective as injection sclerotherapy in controlling bleeding in patients with severe liver disease or in those actively bleeding at the time of their endoscopy. The relative risk of rebleeding whilst receiving somatostatin compared to injection sclerotherapy was 1.39 [95% Confidence Interval (CI) 3.73; 0.52], but this was reduced to 0.98 (95% CI 0.37; 2.67) when readjusted for Child's grading, the only prognostic factor shown to be of significance. Mortality was not significantly different between the two groups of patients (p = 0.31). The relative risk of dying whilst receiving somatostatin compared to injection sclerotherapy was 1.6 (95% CI 3.93; 0.66) but was reduced to 1.03 (95% CI 0.47; 2.47) when adjusted for Child's grading, the only significant prognostic factor. Complications in the somatostatin group were minor and less frequent than after injection sclerotherapy. The results of this study indicate that somatostatin is a safe treatment, which is as effective an endoscopic injection sclerotherapy for acute variceal bleeding.

Blood lipids in middle-aged British men

The concentrations of serum total cholesterol, high density lipoprotein-cholesterol, and triglycerides have been measured in 7735 men aged 40 to 59 years who were drawn from general practices in 24 towns in England, Wales, and Scotland. The distribution of these blood lipids, their interrelations and their association with age, social class, body mass index, cigarette smoking, alcohol intake, and physical activity at work have been examined. Body mass index emerges as the factor most strongly associated with these three blood lipids. Serum total cholesterol increased with increasing body mass index until about 28 kg/m2 but thereafter showed no further rise. The relation between body mass index and high density lipoprotein-cholesterol was negative and linear; that between body mass index and triglycerides was positive and linear. The inverse relation between high density lipoprotein-cholesterol and triglycerides was independent of the fact that both were related to body mass index. Alcohol intake was associated with increased high density lipoprotein-cholesterol concentrations and cigarette smoking with lowered high density lipoprotein concentrations; the association with alcohol appeared to be dominant. No significant trends with age were observed for the three blood lipids. In this population, body mass index is closely associated with the concentration of blood lipids but its effects are probably indirect and mediated by a complex of dietary and other factors.

Diurnal variations in serum biochemical and haematological measurements

Twenty five biochemical and haematological measurements were determined on nonfasting blood and serum samples collected between 9 am and 7 pm from a representative group of 7685 British middle-aged men. Most measurements showed significant diurnal variations, but only for bilirubin, phosphate, and triglyceride did time of day account for more than 5% of the between subject variance. Serum bilirubin concentrations showed a pronounced downward trend in the afternoon, the mean value after 6 pm being 30% lower than the mean value in the morning. Mean serum triglyceride and phosphate concentrations increased steadily through the day. Mean concentrations of potassium, haemoglobin, and haematocrit and red cell count were higher in the morning, while urea and creatinine concentrations and white cell count had higher means in the afternoon. Glucose showed a pattern consistent with short term response to meals. The effects of these diurnal trends on routine use of biochemical tests needs careful consideration, and a greater understanding of their biological mechanisms is required.

Blood lead concentration, blood pressure, and renal function

Blood lead concentrations were related to blood pressure and indicators of renal function in a clinical survey of 7735 middle aged men from 24 British towns. There was no overall evidence that blood lead concentrations were associated with systolic or diastolic blood pressure (r = +0.03 and +0.01, respectively). In the 74 men with a blood lead concentration of 1.8 mumol/l (37.3 micrograms/100 ml) or more there was some suggestion of increased hypertension, but this did not reach significance. Blood lead concentration did not have any relation with serum creatinine concentration. Moderate increases in blood lead concentration were associated with small increases in mean serum urate concentration and small decreases in mean serum urea concentration; these associations were both reduced when alcohol consumption was taken into account. There is no indication that exposure to lead at concentrations commonly encountered in British men is responsible for impaired renal function or increased blood pressure.

Biochemical and haematological response to alcohol intake

In a clinical survey of 7735 middle-aged men, alcohol consumption has been related to 25 biochemical and haematological measurements obtained from a single blood sample. Most measurements showed some association with alcohol consumption, gamma-glutamyl transferase (GGT) being the most strongly associated. Lead, mean corpuscular haemoglobin (MCH), mean corpuscular volume, high-density lipoprotein-cholesterol (HDL-C), urate and aspartate transaminase also showed substantial associations with alcohol intake. Using a discriminant analysis technique, a simple score based on five variables (GGT, HDL-C, urate, MCH and lead) provided the best discrimination between heavy drinkers (e.g. more than three pints of beer daily) and occasional drinkers, but still failed to identify more than half of the heavy drinkers. This combined score may prove a useful measure of an individual's biochemical/haematological response to alcohol consumption for use in epidemiological and clinical studies of alcohol related disorders. The use of such indices should complement but not replace measures of alcohol intake derived from questionnaires.

Psychiatric illness in residential homes for the elderly: a survey in one London borough

The mental state, demographic details, dependency level and presence of problem behaviours have been recorded for 438 (82%) of the residents of the 12 Part III homes, managed by the London Borough of Camden, using standard interview. One third of the residents were suffering from severe dementia, another third from mild to moderate dementia and one third were free of dementia. Of the latter two groups, 38% were depressed. The prevalence rate of dementia increased with the age of the resident and was higher among females. Depression was associated with the presence of visual handicap and incontinence, and was commoner when the resident had been admitted from his own home or belonged to a minority religion. A third of residents needed daily help with dressing and use of the lavatory, one quarter were incontinent each day. Depression and dementia both were associated with increased rates of dependency and of problem behaviours (incontinence, wandering, aggression). This survey has revealed evidence of sufficient psychiatric morbidity in these homes to support a re-appraisal of their current aims, staffing and health-care provision.

High energy neutron treatment for pelvic cancers: study stopped because of increased mortality

OBJECTIVE

To compare high energy fast neutron treatment with conventional megavoltage x ray treatment in the management of locally advanced pelvic carcinomas (of the cervix, bladder, prostate, and rectum).

DESIGN

Randomised study from February 1986; randomisation to neutron treatment or photon treatment was unstratified and in the ratio of 3 to 1 until January 1988, when randomisation was in the ratio 1 to 1 and stratified by site of tumour.

SETTING

Mersey regional radiotherapy centre at Clatterbridge Hospital, Wirral.

PATIENTS

151 patients with locally advanced, non-metastatic pelvic cancer (27 cervical, 69 of the bladder, seven prostatic, and 48 of the rectum).

INTERVENTION

Randomisation to neutron treatment was stopped in February 1990.

MAIN OUTCOME MEASURES

Patient survival and causes of death in relation to the development of metastatic disease and treatment related morbidity.

RESULTS

In the first phase of the trial 42 patients were randomised to neutron treatment and 14 to photon treatment, and in the second phase 48 to neutron treatment and 47 to photon treatment. The relative risk of mortality for photons compared with neutrons was 0.66 (95% confidence interval 0.40 to 1.10) after adjustment for site of tumour and other important prognostic factors. Short term and long term complications were similar in both groups.

CONCLUSIONS

The trial was stopped because of the increased mortality in patients with cancer of the cervix, bladder, or rectum treated with neutrons.

The relationship between blood lead, blood pressure, stroke, and heart attacks in middle-aged British men

The relationship between blood lead concentration and blood pressure is examined in a survey of 7371 men aged 40 to 59 from 24 British towns. After allowance for relevant confounding variables, including town of residence and alcohol consumption, there exists a very weak but statistically significant positive association between blood lead and both systolic and diastolic blood pressure. These cross-sectional data indicate that an estimated mean increase of 1.45 mm Hg in systolic blood pressure occurs for every doubling of blood lead concentration with a 95% confidence interval of 0.47 to 2.43 mm Hg. After 6 years of follow-up, 316 of these men had major ischemic heart disease, and 66 had a stroke. After allowance for the confounding effects of cigarette smoking and town of residence there is no evidence that blood lead is a risk factor for these cardiovascular events. However, as the blood lead-blood pressure association is so weak, it is unlikely that any consequent association between lead and cardiovascular disease could be demonstrated from prospective epidemiological studies. An overview of data from this and other large epidemiological surveys provides reasonably consistent evidence on lead and blood pressure. While NHANES II data on 2254 U.S. men indicate a slightly stronger association between blood lead and systolic blood pressure, data from two Welsh studies on over 2000 men did not show a statistically significant association. However, the overlapping confidence limits for all these studies suggest that there may be a weak positive statistical association whereby systolic blood pressure is increased by about 1 mm Hg for every doubling of blood lead concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Lead exposure and children's intellectual performance

The Institute of Child Health/Southampton study is the largest cross-sectional survey of lead exposure and children's intelligence. 402 six year olds in London with tooth lead concentration in three pre-defined ranges were selected for neuropsychological testing. This paper presents new findings on the relationship between child IQ and tooth lead levels which build on previous findings in four respects: Rather than simply classifying children into high, medium and low lead groups the actual concentrations of lead in each child's tooth have been used to provide a more powerful assessment of the association between IQ and body lead burden. The influence of parental and social factors on child IQ is explored in detail in order to see if any residual lead-IQ association exists after allowance for such confounders. The methods of multiple regression, including an 'optimal' statistical policy, are more fully described. The possibility of interactions between lead and confounders is explored. Findings are that parental IQ is the most important influence on child IQ, though several other factors (eg: family size, social class and quality of marital relationships) were also significantly related. There was no overall evidence that tooth lead concentrations were related to child IQ once these other factors were taken into account. However, a significant interaction between tooth lead and sex of child indicates that the lead-IQ association appears much more pronounced in boys. This unexpected finding needs cautious interpretation and further exploration in other studies.

Urine flow rates in male and female urodynamic patients compared with the Liverpool nomograms

The Liverpool male and female nomograms provide normal reference ranges for the maximum and average urine flow rates over a wide range of voided volumes. A known urine flow rate, in combination with the respective voided volume (and in men the age), can be converted into an equivalent centile ranking, using the equation for the relevant nomogram. Centile rankings allow the urine flow rates of specific male and female populations to be compared. The maximum and average urine flow rates of urodynamic patients (504 consecutive male and 168 consecutive female) were converted into centile rankings. These centile rankings were then compared with the respective urodynamic diagnoses. The median centile rankings for their maximum and average urine flow rates were 21 and 11 (male) respectively and 31 and 18 (female) (vs 50 for the normal populations). The low urine flow rates applied to all diagnostic groups, including those symptomatic men and women who were found to be urodynamically normal. Low urine flow rates may be one of a number of subtle manifestations of urological disease in these patients. Men with obstruction and women with voiding difficulties had the lowest urine flow rates. The 25th centile (men) and the 10th centile (women) appeared to be most appropriate lower limits of normality for both urine flow rates to identify those men more likely to be obstructed and those women at higher risk of voiding difficulties. Men and women with detrusor instability had the highest urine flow rates. Detrusor instability was present in 71% of men with centile rankings for the maximum urine flow rate over 50; 50% of women whose maximum urine flow rate centiles were over 90 had detrusor instability.

Tuberculin testing in residential homes for the elderly

BACKGROUND

Evidence from the United States has shown that tuberculin sensitivity increases with length of stay among residents in homes for the elderly, implying an increasing risk of infection. There is no evidence as to whether or not residents in homes in the United Kingdom have a similar risk.

METHODS

A study was undertaken to determine whether residence in a home for the elderly increases the risk of tuberculosis infection. Over a six month period all residents in homes for the elderly in Liverpool received a tuberculin test. A health questionnaire was completed by the field team for each resident. A total of 2665 residents in homes for the elderly were surveyed.

RESULTS

Heaf test grade positivity declined with age, the odds ratio being 0.71 for each 10 year period. Adjusting for age, there was no change in Heaf test grade with length of stay in the home. Heaf test positivity was stronger in smokers (odds ratio 1.59) than ex-smokers (odds ratio 1.20) and non-smokers. Heaf test grade positivity was directly related to pack years. Allowing for age and smoking, the odds ratio for men compared with women for a positive test was 1.62 (95% confidence interval 1.32 to 1.99).

CONCLUSIONS

Heaf test positivity declines with age. Residence in a home for the elderly is not associated with increased rate of tuberculosis sensitivity. Smoking and male gender is associated with increased Heaf test positivity.

Psychiatric illness in elderly residents of Part III homes in one London Borough: prognosis and review

The psychiatric morbidity among 390 (89%) residents of the 12 Part III homes managed by the London Borough of Camden has been assessed using a standard interview, for comparison with data obtained from residents in a previous survey. Fewer residents were now assessed as having no evidence of dementia or depression, the proportion with some degree of dementia having risen in the 3.6-years follow-up period. Of the original residents, 64% were no longer present by the time of the second survey; the great majority were likely to have died. Residents who had previously been assessed as severely demented or depressed were over-represented in this group. Of the residents who remained, only 17% of those previously depressed had recovered. This evidence suggests that Part III homes are continuing to amass a large number of residents suffering from dementia and depression. The need for adequate psychogeriatric services to Part III homes remains pressing.

Orthodontic treatment for posterior crossbites

BACKGROUND

'Posterior crossbite' occurs when the top back teeth bite inside the bottom back teeth. When it affects one side of the mouth the lower jaw may have to move to one side to allow the back teeth to meet together. This movement may have long term effects on the growth of the teeth and jaws. It is unclear what causes posterior crossbites and they may develop or improve at any time from when the baby teeth come into the mouth to when the adult teeth come through. Several treatments have been recommended to correct them. Some treatments widen the upper teeth whilst others are directed at treating the cause of the posterior crossbite e.g. breathing problems or sucking habits. Most treatments have been used at each stage of dental development.

OBJECTIVES

The aim of this review was to identify and evaluate orthodontic treatments used to expand the maxillary dentition and / or correct posterior crossbites.

SEARCH STRATEGY

All randomised and controlled clinical trials identified from the Cochrane Controlled Trials Register according to the Oral Health Group Search Strategy and stored in the Cochrane Collaboration Oral Health Group Database of Clinical Trials, a MEDLINE search using the Mesh term and free text words, hand searching the British, European and American journals of orthodontics and Angle Orthodontist, and the bibliographies of papers and review articles which reported the outcome of orthodontic treatment to expand the maxillary dentition and/or correct a posterior crossbite that were published as abstracts or papers between 1970 and 1997 in English.

SELECTION CRITERIA

All randomised and controlled clinical trials published as full papers or abstracts which reported quantitative data on the outcomes crossbite correction, molar and/or canine expansion, signs and symptoms of temporomandibular joint dysfunction or respiratory disease.

DATA COLLECTION AND ANALYSIS

Data were extracted without blinding to the authors, treatments used or results obtained. The first named authors of randomised and controlled clinical trials were written to in an attempt to establish the method of randomisation / allocation and identify unpublished studies. Odds ratio, 95% confidence intervals, relative risk, relative risk reduction, absolute risk reduction, and the number need to treat were calculated for event data. The weighted mean difference and 95% confidence intervals were calculated for continuous data.

MAIN RESULTS

Using the search strategy 7 randomised and 5 controlled clinical trials were identified but following correspondence with the authors, 3 of the randomised and 1 of the controlled clinical trials were reclassified giving 5 randomised and 7 controlled clinical trials for inclusion in the review. Trials comparing occlusal grinding in the primary dentition with/without an upper removable expansion appliance in the mixed dentition versus no treatment, banded versus bonded rapid maxillary expansion, banded versus bonded slow maxillary expansion, transpalatal arch with/without buccal root torque and an upper removable expansion appliance versus quad-helix were identified. Occlusal grinding in the primary dentition with/without the addition of an upper removable expansion plate, in the mixed dentition for those children who did not respond to grinding, was shown to be effective in preventing a posterior crossbite in the primary dentition from being perpetuated to the mixed and permanent dentitions. No evidence of a difference in treatment effect (molar and canine expansion) between the test and control intervention was found in the trials which compared banded versus bonded rapid maxillary expansion, banded versus bonded slow maxillary expansion, transpalatal arch with/without buccal root torque, or upper removable expansion appliance versus quad-helix. (ABSTRACT TRUNCATED)

Progressive human immunodeficiency virus-specific immune recovery with prolonged viral suppression

The degree of immune recovery achievable with anti-human immunodeficiency virus (HIV) therapy remains to be established. The effects of potent antiretroviral therapy, including ritonavir and saquinavir, on immune function were studied for a prolonged period in 41 patients. After 96 weeks, 88% of patients had plasma HIV RNA levels below the limit of quantitation. There were continuous increases in CD4 lymphocyte counts and in CD4:CD8 ratios over time. About half the patients developed lymphoproliferative responses to HIV p24 antigen, and nearly all developed responses to phytohemagglutinin. This occurred in parallel with increases in interleukin-12 production and expression of CD28 on CD8 lymphocytes, despite potential antiproliferative effects of protease inhibitors. Transient increases in virus load were temporally associated with loss of proliferative responses. The improved immune function, including HIV-specific immunity in many subjects, demonstrates the potential reversibility of HIV-induced immunodeficiency and does not identify a limit to immune recovery.

Axial length biometry in infants with retinopathy of prematurity

Ultrasound axial length measurements were obtained on infants under a birthweight of 1500 g or 32 weeks gestation undergoing screening for retinopathy of prematurity (ROP). A total of 496 readings were obtained on 171 infants between 32 and 41 weeks post-conceptual age. Other details recorded were maximum stage of acute ROP, birthweight, gestational age, sex, and biparietal and occipitofrontal head diameters. The relationship of these variables to axial growth of the eye was examined using analysis of covariance with a repeated measures approach. Mean axial length increased from 15.27 mm to 16.65 mm in the left eye during this period. Following adjustment for repeated readings a growth rate of 0.18 mm/week was obtained for both eyes. Male infants were found to have longer axial lengths despite correction for birthweight, gestation and head size (p < 0.0001 right and left). Higher stages of acute ROP were also associated with shorter axial length (p < 0.05 for all stages of both eyes) but the rate of growth during the study period did not demonstrate significant differences between stages. Stage 3 infants reaching the threshold for cryotherapy had shorter axial length than stage 3 infants not receiving treatment. The effect of prematurity on the growth of the eye and the significance of these findings with respect to the subsequent development of refractive errors in premature infants are discussed.

Topical or oral ibuprofen for chronic knee pain in older people. The TOIB study

OBJECTIVES

To determine whether GPs should advise their older patients with chronic knee pain to use topical or oral non-steroidal anti-inflammatory drugs (NSAIDs).

DESIGN

An equivalence study was designed to compare the effect of advice to use preferentially oral or topical ibuprofen (an NSAID) on knee pain and disability, NSAID-related adverse effects and NHS/societal costs, using a randomised controlled trial (RCT) and a patient preference study (PPS). Reasons for patient preferences for topical or oral preparations, and attitudes to adverse effects, were explored in a qualitative study.

SETTING

Twenty-six general practices in the UK.

PARTICIPANTS

Participants comprised 585 people with knee pain, aged 50 years or over; 44% were male, mean age 64 years. The RCT had 282 participants: 144 in the oral group and 138 in the topical group. The PPS had 303 participants: 79 in the oral group and 224 in the topical group.

INTERVENTIONS

Advice to use preferentially oral or topical NSAIDs for knee pain.

OUTCOME MEASURES

The primary outcome measure was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcome measures were the Short Form with 36 Items (SF-36), perceived troublesomeness of knee pain, satisfaction with health status, major adverse effects (unplanned hospital admissions and deaths) and minor adverse events over 12 months. The health economic analysis measured the comparative cost per quality-adjusted life-year (QALY) from both an NHS and a societal perspective over 1 and 2 years.

RESULTS

Changes in the global WOMAC score at 12-months were equivalent in both studies: topical - oral, RCT difference=2 [95% confidence interval (CI) -2 to 6], PPS difference=1 (95% CI -4 to 6). There were no differences in the secondary outcomes, except for a suggestion, in the RCT, that those in the topical group were more likely to have more severe overall pain and disability as measured by the chronic pain grade, and more likely to report changing treatment because of inadequate pain relief. There were no differences in the rate of major adverse effects but some differences in the number of minor ones. In the RCT, 17% and 10% in the oral and the topical group, respectively, had a defined respiratory adverse effect (95% CI of difference -17% to -2.0%); after 12 months, the change in serum creatinine was 3.7 mmol/l (95% CI 0.9 to 6.5) less favourable in the oral than in the topical group, and 11% of those in the oral group reported changing treatment because of adverse effects compared with 1% in the topical group (p=0.02). None of these differences were seen in the PPS. Oral NSAIDs cost the NHS 191 pounds and 72 pounds more per participant over 1 year in the RCT and PPS respectively. In the RCT the cost per QALY in the oral group, from an NHS perspective, was in the range 9000-12,000 pounds. In the PPS it was 2564 pounds over 1 year, but over 2 years the oral route was more cost-effective. Patient preference for medication type was affected by previous experience of medication (including adverse reactions), other illness, pain elsewhere, anecdotes, convenience, severity of pain and perceived degree of degeneration. Lack of understanding about knee pain and the action of medication led to increased tolerance of symptoms. Potentially important symptoms may inadvertently have been disregarded, increasing participants' risk of suffering a major adverse effect.

CONCLUSIONS

Advice to use either oral or topical preparations has an equivalent effect on knee pain, but oral NSAIDs appear to produce more minor adverse effects than topical NSAIDs. Generally, these results support advising older people with knee pain to use topical rather than oral NSAIDS. However, for patients who prefer oral NSAID preparations rather than a topical NSAID, particularly those with more widespread or severe pain, the oral route is a reasonable treatment option, provided that patients are aware of the risks of potentially serious adverse effects from oral medication. Further research is needed into strategies to change prescribing behaviour and ensure that older patients are aware of the potential risks and benefits of using NSAIDs. Observational studies are needed to estimate rates of different predefined minor adverse effects associated with the use of oral NSAIDs in older people as are long-term studies of topical NSAIDs in those for whom oral NSAIDs are not appropriate.

Reduction in exposure to lead from drinking water and its effect on blood lead concentrations

The water supply in Ayr (Scotland, UK) was plumbosolvent and many dwellings in Ayr contained lead pipes. In 1981 treatment of the water supply to reduce its plumbosolvency was initiated. Measurements of water and blood lead concentrations were made before and subsequent to the treatment. Most of the measurements made before and after water treatment began were made on water samples from the same dwellings and blood samples from the same women. Water treatment produced a sharp fall in water lead concentrations and a decrease in the median blood lead concentration from 21 to 13 micrograms/100 ml. Two women had higher than expected blood lead concentrations, both these women had been removing old paint. Women who had lead pipes removed from their dwellings all showed substantial decreases in their blood lead concentrations. The curvilinearity of the relation between blood lead and water lead concentrations is confirmed. Even relatively low (less than 40 micrograms/l) water lead concentrations may make a substantial contribution to blood lead concentrations.

An investigation of the effects on children of tooth extraction under general anaesthesia in general dental practice

OBJECTIVE

To describe the morbidity related to general anaesthesia provided in general dental practices for the extraction of teeth in school children.

DESIGN

Observational study supported by structured questionnaires and interviews.

SETTING

Three general dental practices in a Lancashire health district and children's homes.

SUBJECTS

80 children aged 5-15 years undergoing extractions under general anaesthesia.

MAIN OUTCOME MEASURES

Observed demeanour of the children prior to, during and immediately after the surgical procedures. Reported morbidity during the following 24 hours and 1 month later.

RESULTS

92% of the children complained of symptoms associated with the surgery under general anaesthesia. Distress was noted in 16 (20%) patients during the induction of 26 (33%) during recovery. Continued crying was reported for 24 (39%) during the journey home and for 23 (37%) once home had been reached. Other symptoms included nausea, vomiting, sickness and prolonged bleeding. Six reported psychological trauma 1 month after; three had nightmares, two had continuing bad memories and one was depressed for several days.

CONCLUSION

Morbidity following extractions under general anaesthesia in general dental practice is common and has distressing consequences for the young patients and their carers.

Blood cadmium concentrations in the general population of British middle-aged men

Blood cadmium concentrations were determined for 6919 men aged 40-59 randomly selected from general practice registers in 24 British towns. The mean and median blood cadmium were 1.9 and 1.4 micrograms/1 respectively and the distribution was highly skewed. The mean levels in non-smokers was 1.0 micrograms/l and current smokers showed a marked gradient with the daily amount smoked, with a mean of 3.9 micrograms/l in men smoking 40 or more cigarettes per day. Whereas 95% of men who never smoked had blood cadmium less than 2.0 micrograms/l, 80% of men smoking 20 or more cigarettes a day exceeded this figure. 1% of the men had blood cadmium concentrations greater than or equal to 7 micrograms/l virtually all of whom currently smoked cigarettes. Blood cadmium levels in ex-smokers were much lower than in current smokers even for those who had stopped within the past year. However, the mean levels in ex-smokers remained higher than the 'never smoked' for several years after stopping. There was little evidence that age, social class, or alcohol consumption were associated with blood cadmium levels after allowance for cigarette smoking. There is substantial geographic variation in mean blood cadmium for middle-aged men which could not be completely accounted for by smoking differences. Towns in the south and east of England all had mean levels under 2.0 micrograms/l whereas the majority of towns in other parts of Britain had mean levels greater than 2.0 micrograms/l. Possible reasons for this geographic pattern (e.g. geochemistry, industrial exposure, dietary differences) need further exploration.