Views of medical students: what, when and how do they want statistics taught?

BACKGROUND: A key skill for a practising clinician is being able to do research, understand the statistical analyses and interpret results in the medical literature. Basic statistics has become essential within medical education, but when, what and in which format is uncertain. METHODS: To inform curriculum design/development we undertook a quantitative survey of fifth year medical students and followed them up with a series of focus groups to obtain their opinions as to what statistics teaching they want, when and how. RESULTS: A total of 145 students undertook the survey and five focus groups were held with between 3 and 9 participants each. Previous statistical training varied and students recognised their knowledge was inadequate and keen to see additional training implemented. Students were aware of the importance of statistics to their future careers, but apprehensive about learning. Face-to-face teaching supported by online resources was popular. Focus groups indicated the need for statistical training early in their degree and highlighted their lack of confidence and inconsistencies in support. CONCLUSION: The study found that the students see the importance of statistics training in the medical curriculum but that timing and mode of delivery are key. The findings have informed the design of a new course to be implemented in the third undergraduate year. Teaching will be based around published studies aiming to equip students with the basics required with additional resources available through a virtual learning environment.

Non-pharmacological interventions to reduce the risk of diabetes in people with impaired glucose regulation: a systematic review and economic evaluation.

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) is increasing in the UK and worldwide. Before the onset of T2DM, there are two conditions characterised by blood glucose levels that are above normal but below the threshold for diabetes. If screening for T2DM in introduced, many people with impaired glucose tolerance (IGT) will be found and it is necessary to consider how they should be treated. The number would depend on what screening test was used and what cut-offs were chosen. OBJECTIVE: To review the clinical effectiveness and cost-effectiveness of non-pharmacological interventions, including diet and physical activity, for the prevention of T2DM in people with intermediate hyperglycaemia. DATA SOURCES: Electronic databases, MEDLINE (1996-2011), EMBASE (1980-2011) and all sections of The Cochrane Library, were searched for systematic reviews, randomised controlled trials (RCTs) and other relevant literature on the effectiveness of diet and/or physical activity in preventing, or delaying, progression to T2DM.The databases were also searched for studies on the cost-effectiveness of interventions. REVIEW METHODS: The review of clinical effectiveness was based mainly on RCTs, which were critically appraised. Subjects were people with intermediate hyperglycaemia, mainly with IGT. Interventions could be diet alone, physical activity alone, or the combination. For cost-effectiveness analysis, we updated the Sheffield economic model of T2DM. Modelling based on RCTs may not reflect what happens in routine care so we created a 'real-life' modelling scenario wherein people would try lifestyle change but switch to metformin after 1 year if they failed. RESULTS: Nine RCTs compared lifestyle interventions (predominantly dietary and physical activity advice, with regular reinforcement and frequent follow-up) with standard care. The primary outcome was progression to diabetes. In most trials, progression was reduced, by over half in some trials. The best effects were seen in participants who adhered best to the lifestyle changes; a scenario of a trial of lifestyle change but a switch to metformin after 1 year in those who did not adhere sufficiently appeared to be the most cost-effective option. LIMITATIONS: Participants in the RCTs were volunteers and their results may have been better than in general populations. Even among the volunteers, many did not adhere. Some studies were not long enough to show whether the interventions reduced cardiovascular mortality as well as diabetes. The main problem is that we know what people should do to reduce progression, but not how to persuade most to do it. CONCLUSION: In people with IGT, dietary change to ensure weight loss, coupled with physical activity, is clinically effective and cost-effective in reducing progression to diabetes. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Weight loss interventions in young people (18 to 25 year olds): a systematic review.

This systematic review assesses weight loss interventions in young adults (18-25 years), who are vulnerable to weight gain. This age group experience critical life course points (leaving home for higher studies or job, pregnancy, cohabitation) and develop/establish lifestyle and behavioural patterns making this an opportune intervention period. Medline, Embase, Cinahl, PsychINFO and Cochrane Library were searched (1980 to March 2008). All trials and cohort studies with control groups that assessed weight loss interventions in this specific age group were included finally identifying 14 studies. Before and after comparison of behavioural/motivational interventions (-2.40 kg; 95% CI -5.4 to 0.6) and combination interventions (-2.96; 95% CI -4.4 to -1.5) consistently showed weight loss. Behavioural/motivational interventions increased self-efficacy, the desire to control weight, boosted self-esteem, and increased satisfaction with body areas and appearance. Interventions also showed improvements in HDL cholesterol, insulin, glucose and maximum oxygen uptake. However, recruitment to participation in interventions was a barrier for this age group with small sample sizes and short-term interventions. There may be gender differences in preference to participation in certain type of interventions. Further research to understand attitudes towards healthy lifestyle and preferences of interventions is needed to develop suitable interventions for this vulnerable age group.

Obesity as an independent risk factor for elective and emergency caesarean delivery in nulliparous women--systematic review and meta-analysis of cohort studies.

The objective of the study was to investigate the association between increasing maternal body mass index (BMI) and elective/emergency caesarean delivery rates. Systematic review and meta-analysis of published cohort studies were used. The bibliographic databases, MEDLINE, EMBASE, CINAHL, were searched systematically, with no language restrictions, from 1996 to May 2007. MeSH terms and key words for 'pregnancy', 'obesity', 'overweight,''body mass index' and 'caesarean section' were combined with the Cochrane Collaboration strategy for identifying primary studies. Finally, 11 papers were considered eligible for inclusion in the review. Although all the papers were cohort studies, only three were prospective in nature. Compared with women with normal BMI (20-25 kg m(-2)), the crude pooled odds ratios (95% confidence intervals) for caesarean section in overweight (BMI 25-30 kg m(-2)), obese (BMI 30-35 kg m(-2)) and morbidly obese (BMI > 35 kg m(-2)) women were 1.53 (1.48, 1.58), 2.26 (2.04, 2.51) and 3.38 (2.49, 4.57) respectively. The pooled odds of having an emergency caesarean section were 1.64 (95% confidence intervals 1.55, 1.73) in overweight and 2.23 (2.07, 2.42) in obese women. Caesarean delivery risk is increased by 50% in overweight women and is more than double for obese women compared with women with normal BMI.

Effects of treating postnatal depression on mother-infant interaction and child development: systematic review.

BACKGROUND: Postnatal depression has detrimental effects on the child's cognitive and emotional development. AIMS: To assess the benefits of treating postnatal depression for mother-infant interaction and child development. METHOD: A systematic search was made of 12 electronic bibliographic databases for randomised controlled trials and controlled clinical trials on treatment of mothers with postnatal depression, where outcomes were assessed in children; findings were assessed. RESULTS: Only eight trials met the inclusion criteria. Of those included, interventions varied widely but all involved therapies directed at the mother-infant relationship. One study with intensive and prolonged therapy showed cognitive improvement, whereas two others with briefer interventions improved maternal-infant relationships but did not affect the child's cognitive or behavioural development. All five studies assessing only mother-infant relationships showed improvements. CONCLUSIONS: Cognitive development in children of depressed mothers, along with better mother-infant relationships, might be improved with sustained interventions. Trials assessing treatments for postnatal depression would benefit from looking more closely at benefits for children as well as mothers, using validated objective measures.

Long-term weight loss effects on all cause mortality in overweight/obese populations.

This systematic review assesses the long-term effectiveness of weight loss on all cause mortality in overweight/obese people. Medline, Embase and Cinahl were searched (1966-2005). Cohort studies and trials on participants with body mass index > or =25 kg m(-2), with weight change and mortality with > or =2-year follow-up, were included finally identifying 11 papers based on eight studies. There may be gender differences in the benefits for all cause mortality. The impact of weight loss in men on mortality was not clear with some studies indicating weight loss to be detrimental, while a recent cohort study showed benefits, if it were a personal decision. Other studies with no gender separation had similarly mixed results. However, one study indicated that overweight/obese women with obesity-related illness, who lost weight intentionally within 1 year, had significantly reduced mortality rates of 19-25%. In contrast, studies of overweight/obese diabetics irrespective of gender showed significant benefit of intentional weight loss on mortality in a meta-analysis, hazard ratios = 0.75 (0.67-0.83). There is some evidence that intentional weight loss has long-term benefits on all cause mortality for women and more so for diabetics. Long-term effects especially for men are not clear and need further investigation.

Systematic review of the long-term effects and economic consequences of treatments for obesity and implications for health improvement.

OBJECTIVES: To undertake a systematic review of the long-term effects of obesity treatments on body weight, risk factors for disease, and disease. METHODS: The study encompassed three systematic reviews that examined different aspects of obesity treatments. (1) A systematic review of obesity treatments in adults where the methods of the Cochrane Collaboration were applied and randomised controlled trials (RCTs) with a follow-up of at least 1 year were evaluated. (2) A systematic epidemiological review, where studies were sought on long-term effects of weight loss on morbidity and/or mortality, and examined through epidemiological modelling. (3) A systematic economic review that sought reports with both costs and outcomes of treatment, including recent reports that assessed the cost-effectiveness of pharmaceutical and surgical interventions. A Markov model was also adopted to examine the cost-effectiveness of a low-fat diet and exercise intervention in adults with obesity and impaired glucose tolerance. RESULTS: The addition of the drugs orlistat or sibutramine was associated with weight loss and generally improved risk factors, apart from diastolic blood pressure for sibutramine. Metformin was associated with decreased mortality after 10 years in obese people with type 2 diabetes. Low-fat diets were associated with continuing weight loss for 3 years and improvements in risk factors, as well as prevention of type 2 diabetes and improved control of hypertension. Insufficient evidence was available to demonstrate the benefits of low calorie or very low calorie diets. The addition of an exercise or behaviour programme to diet was associated with improved weight loss and risk factors for at least 1 year. Studies combining low-fat diets, exercise and behaviour therapy suggested improved hypertension and cardiovascular disease. Family therapy was associated with improved weight loss for 2 years compared to individual therapy. There was insufficient evidence to conclude that individual therapy was more beneficial than group therapy. Weight lost more quickly (within 1 year), from the epidemiology review, may be more beneficial with respect to the risk of mortality. The effects of intentional weight loss need further investigation. Weight loss from surgical and non-surgical interventions for people suffering from obesity was associated with decreased risk of development of diabetes, and a reduction in low-density lipoprotein cholesterol, total cholesterol and blood pressure, in the long term. Targeting high-risk individuals with drugs or surgery was likely to result in a cost per additional life-year or quality-adjusted life-year (QALY) of no more than 13,000 British pounds. There was also suggestive evidence of cost saving from treatment of people with type 2 diabetes with metformin. Targeting surgery on people with severe obesity and impaired glucose tolerance was likely to be more cost-effective at 2329 British pounds per additional life-year. Economic modelling over 6 years for diet and exercise for people with impaired glucose tolerance was associated with a high initial cost per additional QALY, but by the sixth year the cost per QALY was 13,389 British pounds. Results did not include cost savings from diseases other than diabetes, and therefore may be conservative. CONCLUSIONS: The drugs orlistat and sibutramine appear beneficial for the treatment of adults with obesity, and metformin for obese patients with type 2 diabetes. Exercise and/or behaviour therapy appear to improve weight loss when added to diet. Low-fat diets with exercise, or with exercise and behaviour therapy are associated with the prevention of type 2 diabetes and hypertension. Long-term weight loss in epidemiological studies was associated with reduced risk of type 2 diabetes, and may be beneficial for cardiovascular disease. Low-fat diets and exercise interventions in individuals at risk of obesity-related illness are of comparable cost to drug treatments. Long-term pragmatic RCTs of obesity treatments in populations with obesity-related illness or at high risk of developing such illness are needed (to include an evaluation of risk factors, morbidity, quality of life and economic evaluations). Drug trials that include dietary advice, plus exercise and/or behaviour therapy are also needed. Research exploring effective types of exercise, diet or behaviour and also interventions to prevent obesity in adults is required.

Effects of weight loss in overweight/obese individuals and long-term lipid outcomes--a systematic review.

This paper aims to review the evidence for long-term effectiveness of weight loss on cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides in overweight/obese people. Current evidence is mostly based on short-term studies. A systematic review of long-term lipid outcomes of weight loss in studies published between 1966 and 2001, was conducted. Inclusion criteria included all cohort studies and trials carried out on participants with body mass index of greater than or equal to 28 kg m(-2). Studies had at least two weight change measurements and follow-up of more than 2 years. Thirteen long-term studies with a follow-up of more than 2 years were included. Cholesterol has a significant positive linear relationship with weight change (r = 0.89) where change in weight explains about 80% of the cholesterol difference variation (Adj R2 = 0.80). For every 10 kg weight loss a drop of 0.23 mmol L(-1) in cholesterol may be expected for a person suffering from obesity or are grossly overweight. Weight loss has long-term beneficial effects especially on LDL and cholesterol. Weight loss in obese patients should be encouraged and sustained.

Weight loss in obese diabetic and non-diabetic individuals and long-term diabetes outcomes--a systematic review.

The aim was to review the evidence for the long-term effects of weight loss on diabetes outcomes in obese people or for those at risk of developing type 2 diabetes. Current evidence is mostly based on short-term studies. This is a systematic review of long-term outcomes of weight loss in studies published between 1966 and 2001. Eleven long-term studies with a follow up of more than 2 years were included. Results show that those with diabetes who lost weight intentionally significantly reduced their mortality risks by 25%. Additionally, weight loss of 9-13 kg was most protective. Patients with the risk of developing diabetes due to either family history of diabetes or impaired glucose tolerance, saw a reduction in this risk. Those with large weight losses achievable with surgical interventions reduced their risk by at least 63%. Metabolic handling of glucose improved in 80% of those already with type 2 diabetes who lost weight. Based on one large study, intentional weight loss in obese patients appears to have a beneficial effect on mortality risk for those with type 2 diabetes. Clearly, further studies are needed to endorse this. The risk of developing diabetes being reduced by weight loss was shown in seven studies. However, the results were from studies with different analytical adjustments and outcome indices, making it difficult to make direct comparisons and should be viewed with caution. More long-term prospective studies need to be conducted with commitment to improving the methodological quality and standardization, in order to accurately assess the long-term effects of weight loss for obese diabetic and non-diabetic individuals.

The prevalence of chronic chest and leg pain following cardiac surgery: a historical cohort study.

Chronic pain after surgery is recognised as an important post-operative complication; recent studies have shown up to 30% of patients reporting persistent pain following mastectomy and inguinal hernia repair. No large-scale studies have investigated the epidemiology of chronic pain at two operative sites following coronary artery bypass grafting (CABG). This paper reports the follow-up of a cohort of 1348 patients who underwent cardiac surgery between 1996 and 2000 at one cardiothoracic unit in northeast Scotland. Chronic pain was defined as pain in the location of surgery, different from that suffered pre-operatively, arising post-operatively and persisting beyond 3 months. The survey questionnaire consisted of the short-form-36 (SF-36), Rose angina questionnaire, McGill pain questionnaire and the University of California and San Francisco (UCSF) pain service questionnaire. Of the 1080 responders, 130 reported chronic chest pain, 100 chronic post-saphenectomy pain and 194 reported pain at both surgical sites. The cumulative prevalence of post-cardiac surgery pain was 39.3% (CI(95) 36.4-42.2%) and mean time of 28 months since surgery (SD 15.3 months). Patients who reported pain at both sites had lower quality of life scores across all eight health domains compared to patients with pain at one site only and those who were pain-free. Prevalence of chronic pain decreased with age, from 55% in those aged under 60 years to 34% in patients over 70 years. Patients with pre-operative angina and those who were overweight or obese (BMI>/=25) at the time of surgery were more likely to report chronic pain. Chronic pain following median sternotomy and saphenous vein harvesting is more common than hitherto reported and that patients undergoing CABG should be warned of this possibility.

Chronic pain and quality of life following open inguinal hernia repair.

BACKGROUND: The aim was to determine the frequency and characteristics of chronic pain following open inguinal hernia repair and to identify risk factors for its development. METHODS: This was a questionnaire survey of a historical cohort of patients who underwent inguinal hernia surgery in Aberdeen. The sample comprised all patients (n = 351) who underwent surgery between January 1995 and December 1997, and who were alive and resident in Grampian in October 1999. Outcome measures included self-report of pain persisting for more than 3 months after operation. Pain was characterized by means of the McGill Pain Questionnaire, and quality of life was assessed with the Short Form 36 (SF-36). RESULTS: A total of 226 patients (64 per cent) completed the questionnaire, 67 (30 per cent) of whom reported chronic pain. Reported pain was predominantly neuropathic in character. Patients at increased risk of chronic pain were under 40 years old (P < 0.001), had day-case surgery (P = 0.004), had subsequent surgery on the same side (P < 0.005) and recalled pain before operation (P = 0.005). The SF-36 scores were significantly different in the social functioning, mental health and pain dimensions in patients with chronic pain. CONCLUSION: Chronic pain occurred in 30 per cent of patients after open hernia repair, a higher frequency than has been reported previously. Several risk factors were identified and further prospective research is recommended.