Was John Reid right? Smoking, class, and pleasure: a population-based cohort study in England.

OBJECTIVES: To assess whether there is a relationship between smoking and levels of overall quality of life, or with the pleasure domain of quality of life, in lower socio-economic groups (SES). STUDY DESIGN: Cohort study involving 9176 individuals aged 50 years and over who participated in the Health Survey for England and were followed up in Wave 1 of the English Longitudinal Study of Ageing in 2002. METHODS: We classified smokers as never-smokers, ex-smokers and current smokers, and used household wealth as a marker for socio-economic position. Pleasure was assessed using the pleasure subscale of the CASP-19 instrument, a 19-point measure of quality of life that covers four theoretical domains: control, autonomy, self-realization and pleasure. RESULTS: We found that the odds ratio for experiencing lower than median levels of pleasure for smokers with low SES was 1.42 (95% CI 1.16-1.74), and for all smokers was 1.33 (95% CI 1.17-1.51). The same pattern of associations was found when the outcome was total CASP-19 score or positive GHQ-12 score. CONCLUSIONS: We found no evidence to support a claim that smoking is associated with heightened levels of pleasure, either in people with low SES or in the general population. In fact, our results suggest the opposite: that smoking is associated with lower levels of pleasure and poorer overall quality of life. Policy decisions on smoking should consider its potentially harmful effect on quality of life and pleasure as well as on other aspects of health.

Assessing the temporal reproducibility of human esophageal motor-evoked potentials to transcranial magnetic stimulation.

BACKGROUND: Although the electrophysiological properties and reproducibility of somatic limb motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) are well characterized, little is known about the reproducibility of MEPs for viscerosomatic structures such as the esophagus. AIM: To determine the temporal reproducibility of esophageal MEPs to TMS. METHODS: MEPs to TMS were recorded from the proximal esophagus, using a swallowed catheter housing a pair of electrodes, in eight healthy subjects at five stimulus intensities (SI) (motor threshold [MT] to 20% above MT). For each SI, 20 consecutive TMS stimuli at 5-second intervals were delivered over a single scalp site (dominant hemisphere at site exhibiting MT at lowest SI) and repeated 40 and 80 minutes thereafter. MEP amplitudes and latencies were measured, and means were sequentially calculated for each SI and then log-transformed. The repeatability coefficients (RC) for the three time points were calculated across each set of 20 stimuli and presented as an exponential ratio. RESULTS: Best RC (amplitude/latency) were achieved at 120% SI relative to MT, being 1.8/1.2 (optimal = 1.0). For lower intensities of 115%, 110%, 105%, and 100% SI, the RC were 2.1/1.2, 2.1/1.1, 2.4/1.2, and 2.6/1.4, respectively. For all SI, the greatest reductions in RC occurred over the first 10 stimuli, with little additional gain beyond this number. CONCLUSIONS: Latencies of esophageal MEP to TMS across intensities are highly reproducible, whereas amplitudes are more stimulus intensity-dependent, being most reliable and reproducible at the highest stimulus strengths. SIGNIFICANCE: Using careful parameters, TMS can be used reliably in future studies of viscerosomatic structures, although the size of the response variability needs to be taken into account when assessing changes in cortico-fugal activity.

Need for and receipt of hip and knee replacement--a national population survey.

OBJECTIVES: Hip and knee joint replacements are effective, and yet little is known about how closely the need for joint replacement matches supply in different population groups. Our objective was to compare the prevalence of existing joint replacements with that of need in population groups in England. METHODS: A total of 7101 people aged 60 yrs or older, representative of the population of England, were interviewed. Participants were asked about both receipt and need for joint replacement, socio-economic status and co-morbidity. 'Need' classification was based on hip or knee pain and difficulty walking, with adjustment for potential surgical contraindications. Associations between participants' characteristics and both need and receipt were estimated. RESULTS: The prevalence of existing joint replacement (receipt) was 6% [95% confidence intervals (CI) 5, 6], and this was lower in the North than the South [adjusted odds ratio (OR) 0.72, CI 0.53, 0.96]. In contrast, the prevalence of estimated need was higher in the North (OR 1.27, CI 1.03, 1.58). Need was greater in women than men (OR 1.30, CI 1.09, 1.53), and showed an increasing gradient from the wealthiest to poorest quintile (ORs 1.00, 1.52, 2.18, 2.49, 3.23). In contrast, receipt did not differ significantly by sex or socio-economic group. CONCLUSIONS: People living in the North of England, women and the less wealthy experience relatively high levels of need, yet do not receive relatively more hip and knee joint replacements.

Oral 5-aminosalicylic acid for maintenance of medically-induced remission in Crohn's Disease.

BACKGROUND: Prevention of relapses is a major issue in the management of Crohn's disease. Corticosteroids, the mainstay of treatment of acute exacerbations are not effective in the maintenance of remission and its chronic use is limited by numerous adverse events. A number of randomised controlled trials comparing various 5-ASA agents with either placebo or other drugs have had conflicting results. OBJECTIVES: To conduct a systematic review to evaluate the efficacy of oral 5-ASA agents for the maintenance of medically-induced remission in Crohn's disease. SEARCH STRATEGY: We searched MEDLINE (1966 to January 2004), EMBASE (1984-January 2004), the Cochrane Central Register of Controlled Trials from the Cochrane Library (Issue 1, 2004) and the IBD Review Group Specialized Trials Register. We hand-searched the articles cited in each publication. SELECTION CRITERIA: We included randomised controlled trials which compared oral 5-ASA agents with either placebo or sulphasalazine, with treatment durations of at least 6 months. DATA COLLECTION AND ANALYSIS: Data extraction and assessment of methodological quality of each study were independently performed by two reviewers. Any disagreement among reviewers was resolved by consensus. The main outcome measure was the occurrence of relapse as defined by the primary studies. Odds ratios of relapse rates and their 95% confidence intervals were calculated. MAIN RESULTS: 5-ASA VERSUS PLACEBO. In the main analysis, we used as the denominator the total number of patients randomised. We assumed that participants who dropped out of the study, and on whom there was no post withdrawal information, had relapsed during the study period. Using the fixed effects model, the odds ratio for 6 studies where participants were followed up for 12 months was 1.00 (95%CI, 0.80 to 1.24). Using the random effects model in a sensitivity analysis had little effect on the results with an OR of 0.93 (95% CI, 0.65 to 1.33). For the seventh study where follow up was for 24 months, the odds ratio was 0.98; 95% CI, 0.51 to 1.90. In further sensitivity analyses, we analysed only participants who completed the study and ignored the dropouts. The odds ratio (fixed effects model) for the 6 studies where follow up was for 12 months was 0.74 (95% CI, 0.57 to 0.96), but using the random effects model, the OR was 0.68 (95% CI 0.45 to 1.02). The OR for the seventh study where follow up was for 24 months (Gendre 1993a), was 0.86; 95% CI, 0.42 to 1.78. 5-ASA VERSUS SULPHASALAZINE. We did not find any study that satisfied the inclusion criteria. AUTHORS' CONCLUSIONS: We found no evidence in this review to suggest that 5-ASA preparations are superior to placebo for the maintenance of medically-induced remission in patients with Crohn's disease. Therefore it appears that additional randomised trials of this regime are not justified.

Evaluation of a bedside blood ketone sensor: the effects of acidosis, hyperglycaemia and acetoacetate on sensor performance.

AIMS: To assess the performance of a handheld bedside ketone sensor in the face of likely metabolic disturbances in diabetic ketoacidosis, namely: pH, glucose and acetoacetate. METHODS: The effects of pH (7.44-6.83), glucose (5-50 mmol/l) and acetoacetate (0-5 mmol/l) were examined in venous blood to investigate the accuracy of betahydroxybutyrate measurement (0-5 mmol/l) by a handheld ketone sensor. Sensor results were compared with a reference method. Linear regression models were fitted to the difference between the methods with the concentration of metabolite as the explanatory factor. RESULTS: Decreasing pH and increasing glucose had no effect on the accuracy of the handheld ketone sensor; the gradients of the fitted lines were -0.14 and -0.003, respectively. The 95% confidence intervals were -0.7-0.4 and -0.01-0.004, respectively (P = 0.59 and 0.4, respectively). In the acetoacetate study, a positive relationship between the sensor and reference method results was found, the gradient was 0.09. The 95% confidence interval was 0.05-0.14 (P < or = 0.001), indicating that high concentrations of acetoacetate interfere with the sensor performance. CONCLUSIONS: Acidosis and hyperglycaemia have minimal effects on the sensor performance. However, high concentrations of acetoacetate result in some overestimation of betahydroxybutyrate. This bedside ketone sensor provides useful data over a broad range of conditions likely to be encountered during moderate to severe diabetic ketoacidosis.

Nitrates for achalasia.

BACKGROUND: Achalasia is a disease that impairs oesophageal motility. Though nitrates have been used to treat achalasia for a long time, the effectiveness of nitrates for achalasia is still controversial. OBJECTIVES: To quantify short-term and long-term effects of nitrate therapy in patients with achalasia. SEARCH STRATEGY: Trials were identified by searching the Cochrane Controlled Trials Register (Issue 4-2001), MEDLINE (1966-2001), EMBASE (1980-2001), LILACS - Latin American and Caribbean health science literature (1982-2001) and CBM-Chinese Biomedical database(1980-2000). Additionally, all references in the identified trials were checked for further relevant trials. An updated search was run on the Cochrane Library, MEDLINE, and EMBASE in September 2003 - no new trials were found. SELECTION CRITERIA: All randomised controlled trials involving achalasic patients given any type of nitrates were included. DATA COLLECTION AND ANALYSIS: Data were extracted by two independent observers based on the intention to treat principle. MAIN RESULTS: Two randomised cross-over studies were found, but no results are included. Due to the design of the studies and the method of reporting the results in the original paper it was not possible to extract the necessary information to examine any of the outcomes. REVIEWER'S CONCLUSIONS: We can conclude no implications for practice at this stage. Appropriately designed parallel group randomised controlled trials with long term follow-up are needed to determine the effects of nitrates.

Common statistical errors in the design and analysis of subfertility trials.

BACKGROUND: The quality of clinical trials has received increasing attention with the growth of evidence-based medicine and systematic reviews. We aimed to identify whether errors and omissions commonly encountered when undertaking Cochrane reviews in this field are still passing peer review. METHODS: We undertook a review of trials published in 2001 by two major journals. We selected from Medline only trials in which authors compared pregnancy rates under two interventions by allocating women to different groups. RESULTS: We identified 39 trials meeting our criteria. Six trials were fatally flawed by design, either by inappropriate use of a cross-over design or by systematic allocation described by the authors as 'random'. Only six reports claimed to apply the intention-to-treat principle, and the principle was misunderstood by four of these. Only five trials reported live birth rates sufficiently to allow valid meta-analysis. Most trials (82%) included at least one 'unit of analysis' error. CONCLUSIONS: We selected simple trials from respected journals, assuming that our sample would represent trials of highest methodological quality in the field. Nevertheless, the standards of design, analysis and reporting of many subfertility trials are not sufficient to allow reliable interpretation of results, or inclusion in meta-analyses.

Nitrates for achalasia.

BACKGROUND: Achalasia is a disease that impairs oesophageal motility. Though nitrates have been used to treat achalasia for a long time, the effectiveness of nitrates for achalasia is still controversial. OBJECTIVES: To quantify short-term and long-term effects of nitrate therapy in patients with achalasia. SEARCH STRATEGY: Trials were identified by searching the Cochrane Controlled Trials Register (Issue 4-2001), MEDLINE (1966-2001), EMBASE (1980-2001), LILACS - Latin American and Caribbean health science literature (1982-2001) and CBM-Chinese Biomedical database(1980-2000). Additionally, all references in the identified trials were checked for further relevant trials. SELECTION CRITERIA: All randomised controlled trials involving achalasic patients given any type of nitrates were included. DATA COLLECTION AND ANALYSIS: Data were extracted by two independent observers based on the intention to treat principle. MAIN RESULTS: Two randomised cross-over studies were found, but no results are included. Due to the design of the studies and the method of reporting the results in the original paper it was not possible to extract the necessary information to examine any of the outcomes. REVIEWER'S CONCLUSIONS: We can conclude no implications for practice at this stage. Appropriately designed parallel group randomised controlled trials with long term follow-up are needed to determine the effects of nitrates.

Renal effects of nicardipine in essential hypertension: differences between acute and chronic therapy.

Previous reports have described improvements in renal function with acute administration of nicardipine. The purpose of this study was to determine if these improvements persist with continued treatment. Using single dose radio-isotopic techniques in six subjects with essential hypertension, evaluations of glomerular filtration rate and effective renal plasma flow were made prior to treatment during an intravenous nicardipine infusion of 80 micrograms/kg per h, and following 6 weeks of treatment with 30-40 mg, three times a day. Subjects were stabilized on a diet containing 100 mmol Na+, 80 mmol K+ and 1650 ml water. Blood pressure was similarly reduced with both acute (-45/26 mmHg) and chronic (-42/21 mmHg) therapy. Renal vascular resistance index fell with both acute (-39%) and chronic (-26%) treatment. Significant increases in effective renal plasma flow (+15%), urine volume (+121%), and urinary sodium (+168%) and calcium (+128%) elimination were seen with acute treatment. These parameters had returned to control levels after 6 weeks of treatment. No change was seen in glomerular filtration rate, filtration fraction, plasma renin activity or plasma aldosterone concentration. These data showed that the natriuresis and diuresis as well as the increase in effective renal plasma flow seen with the introduction of nicardipine therapy, did not persist during long-term treatment. There was no evidence of deterioration in any aspect of renal function during long-term therapy despite the significant reduction in renal perfusion pressure.