World Congress of Epidemiology 2011: themes and highlights.

Modern-day epidemiologists are confronted with huge changes, such as the rise in the global population due to reduced mortality, migration within and across countries, massive shifts in economic standing and lifestyles, and environmental degradation. With over 1000 posters, more than 100 oral presentations, 16 workshops, four lunchtime symposia, many exhibitions and immeasurable discussions, the task of capturing all highlights of the International Epidemiology Association (IEA) World Congress of Epidemiology 2011 is impossible, but this article has provided a sample. Many presenters showed that the challenges facing global health are complex, changing and in demand of measurement, and they demonstrated the central role of epidemiology. The cutting-edge methodologies theme promised the emergence of a more transparent, better balanced, but also more critical approach to dealing with bias. Preceding the United Nations high-level meeting on non-communicable diseases (New York, 19th-20th September 2011), the Congress's chronic diseases stream was especially timely. The neglected conditions theme illustrated inspiring work battling against apathy, inertia and ignorance; perhaps the special challenge of the 'neglected conditions epidemiologist'. Translating epidemiology's insights into effective policies and programmes to prevent diseases or reduce their impact is not easy. Speakers highlighted the common failure of epidemiologists to contribute actively to improving the health of the populations they serve, especially the poor and disadvantaged, but also provided many examples where they had done so. The 'other' theme ensured that important studies were not lost from the programme just because they did not fit easily into the specific themes. The studies focused on identified risk factors throughout the life course. A variety of methods were used to identify factors that altered the rate of birth, disease and death. Ongoing epidemiology is not only broad but is also deep, and ever more so as collaborative pooling of expertise, data, populations and ideas has emerged, accelerated by modern-day communication technologies. Epidemiology, and epidemiologists, seem poised for tomorrow's world.

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.

The photocarcinogenic risk of narrowband UVB (TL-01) phototherapy: early follow-up data.

BACKGROUND: Limited information is available on the carcinogenic risk associated with narrowband TL-01 UVB phototherapy in humans. OBJECTIVES: To determine the skin cancer incidence in a population treated with TL-01 phototherapy. PATIENTS AND METHODS: All TL-01-treated patients were identified from the departmental computerized database. Patients with malignant melanoma (MM), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) were identified by record linkage with the Scottish Cancer Registry. The incidence of each was compared with the normal Scottish population matched for age and sex. RESULTS: Data were obtained from 1908 patients. The median follow-up duration was 4 years (range 0.04-13). The median cumulative number of TL-01 treatments and dose were 23 (1-199) and 13 337 (30-284 415) mJ cm(-2), respectively. No increased incidence of SCC or MM was observed. Ten patients developed BCC compared with an expected 4.7 in the Scottish population [standardized rate ratio 213 (95% confidence interval 102-391); P < 0.05]. CONCLUSIONS: A small but significant increase of BCC was detected in the TL-01 group. This could be explained by a number of factors, including ascertainment bias. To determine the true carcinogenic risk of TL-01 phototherapy, longer follow-up is essential.

Prevalence of diabetic eye disease in Tayside, Scotland (P-DETS) study: methodology.

AIMS: To describe the use of a validated diabetes register for sampling frame generation and assessment of the representative nature of participants in a fieldwork study of diabetic eye disease. METHODS: We performed an observational, cross-sectional fieldwork study of diabetic retinal disease using reference standard eye examination. We sampled the entire diabetic population using the Diabetes Audit and Research in Tayside Study (DARTS) diabetes register. RESULTS: The study population comprised 4825 diabetic patients aged over 16 years registered with one of 166 general practitioners (GPs) in 41 practices in Tayside in October 1999. This represented 61.1% of the Tayside diabetic population (7903). A total of 586 (66%; 95% confidence interval 63, 70) patients were examined from a sampling frame of 882 living patients registered with a Tayside GP. Demographic and disease parameters recorded on the DARTS patient register allowed comparison between participants and non-participants. CONCLUSIONS: This study shows the clear benefit of using a complete diabetic population as a sampling frame. This allows potential selection bias and external validity to be evaluated using routine data sources. Studies performed and reported in this way will aid the critical appraisal process.

Partnerships with health and private voluntary organizations: what are the issues for health authorities and boards?

BACKGROUND: The number of voluntary organizations active in health care is considerable. There have been recent calls for a new closer working relationship between voluntary bodies and the National Health Service. The relationship between the two healthcare sectors needs to be efficient and harmonious in the interests of patient care; however, little is known about the nature and problems in the current relationship. The present study was undertaken to examine aspects of this relationship from the point of view of health board personnel. OBJECTIVE: To identify the practices and views of Scottish health board staff concerning the funding, role and responsibility of voluntary organizations in the health sector. METHODS: A qualitative study based on in-depth interviews with health board officials in all 15 Scottish health boards. RESULTS: Policies for financial and other relationships with the voluntary sector were often not explicit. The levels and method of funding voluntary health organizations varied across boards, as did the tenure of awards (from 1 to 3 years). Demand for funding far exceeded monies available. Some health boards ensured accountability through audited accounts, annual reports and site visits; however, others thought this inappropriate for small organizations. Health boards recognized the problems of the precariousness of funding and the administrative burden of the monitoring process and the ritual of applying for funding. CONCLUSION: The uncertainties of long-term funding may impede the contribution of voluntary organizations. There is a tension between the requirements of clinical governance and the ability of small voluntary organizations to provide the necessary documentation. One proposed solution, to reduce the number of organizations, might not appeal to the voluntary sector. Future initiatives could address the problem of tailoring funding and accounting to the resources of voluntary organizations.

What predicts poor collection of medication among children with asthma? A case-control study.

Compliance with asthma medication is recognised to be a problem. Acquisition of medication is the first step towards compliance. Factors predicting poor collection of prophylactic medication were investigated. A case/control study was conducted. Cases were children who had had at least two consultations for poorly controlled asthma in 1 yr and collected prescriptions of prophylactic medication irregularly. Controls were children whose prescriptions were collected as instructed. Levels of knowledge about asthma and asthma medication were high in both groups. Parents of cases were more likely to perceive their child's asthma to be moderate or severe and more likely to report that their child's asthma was not well controlled. They reported more night-time symptoms, exercise symptoms and school absence. Parents of cases were less likely to report that administering inhalers was part of the evening routine. They were less likely to perceive their child's prophylactic medication to be very effective and more reluctant to administer prophylactic medication. Some parents may decide to undertreat their children, although lack of organised routine may contribute to poor compliance. Parents need guidance on interpreting symptoms and support in establishing routines for the administration of medication.

Perindopril improves six minute walking distance in older patients with left ventricular systolic dysfunction: a randomised double blind placebo controlled trial.

OBJECTIVE: To evaluate the effects of the angiotensin converting enzyme inhibitor perindopril on six minute walking distance and quality of life in very old patients with left ventricular systolic dysfunction. DESIGN: Prospective, double blind placebo controlled trial. SETTING: Medicine for the elderly day hospital. PATIENTS: 66 patients (average age 81) with left ventricular systolic dysfunction identified by echocardiography. INTERVENTIONS: 10 weeks of treatment with titrated doses of perindopril or placebo. MAIN OUTCOME MEASURES: Six minute walking distance 10 weeks following treatment, quality of life measurements including the Minnesota living with heart failure questionnaire and the 36 item short form health survey. RESULTS: In patients with left ventricular systolic dysfunction, six minute walking distance was significantly increased in the treatment group (37.1 m) compared with the placebo group (-0.3 m, p < 0.001). The medication was well tolerated and there were no significant adverse events. CONCLUSIONS: Six minute walking distance is improved considerably by treatment with perindopril in older patients with heart failure caused by left ventricular systolic dysfunction.

Urate predicts subsequent cardiac death in stroke survivors.

AIMS: To test the hypothesis that urate predicts cardiac death after stroke independent of conventional risk factors of atherosclerosis, creatinine and diuretic use. METHODS AND RESULTS: Serum urate concentration was measured in an unselected cohort of 354 stroke survivors who were followed-up for a median of 2.8 years. Cardiac death was the primary end-point. Urate was associated with a statistically significant threefold increase in relative risk of cardiac death even after adjustment for other conventional risk factors. In the subgroup of patients who were not on diuretics, raised urate was associated with a 12-fold significant increase in relative risk of cardiac death after adjusting for renal function and other conventional risk factors. A urate concentration of greater than 0.31 mmol. l(-1) was 78% sensitive at predicting cardiac death within 5 years after stroke, but was only 54% specific. If urate exceeded 0.38 mmol. l(-1), specificity of predicting cardiac death within 5 years after stroke was 88%. CONCLUSIONS: Elevated serum urate concentration may be used to stratify risk of future cardiac death after stroke. This appeared to be true even in stroke survivors who were not on diuretic therapy.

Latex allergy at Groote Schuur Hospital--prevalence, clinical features and outcome.

BACKGROUND: The incidence of latex allergy is increasing worldwide but there is very little information available on the clinical outcome for affected individuals. OBJECTIVE: To determine the prevalence of latex allergy at Groote Schuur Hospital, a large teaching hospital in Cape Town, and to study the outcome for affected individuals. METHOD: Using a questionnaire, we screened 2,316 hospital workers for the presence of work-related symptoms. Workers who were symptomatic had Immunocap RAST (CAP RAST) or skin-prick tests to confirm latex sensitivity. Latex-avoidance measures were implemented in positive subjects. One hundred symptomatic, sensitised individuals were followed up 3 months after intervention to assess their clinical status. A further cohort of 25 individuals with ongoing nasal symptoms were studied in detail. RESULTS: Latex sensitisation was confirmed in 182 of 717 symptomatic workers (25.3%). Sensitised symptomatic workers were significantly more likely to have had a previous history of urticaria (P = < 0.001), oral allergy syndrome (P = < 0.001), or allergic conjunctivitis (P = 0.001), but not hay fever, perennial rhinitis, eczema or insect allergies. Latex sensitisation occurred among all classes of health care workers. Ocular and cutaneous symptoms were significantly associated with positive latex sensitisation (P = < 0.001). After latex intervention, ocular symptoms (P = < 0.001), skin rashes (P = < 0.001) and wheezing (P = 0.001) reduced significantly. Nasal symptoms did not improve. Undiagnosed and untreated underlying allergies to common aero-allergens were present in the majority of latex-sensitised patients with ongoing nasal symptomatology. CONCLUSION: The prevalence of symptomatic sensitisation to latex allergy at Groote Schuur Hospital is between 9.2 and 11.2%. Ocular and cutaneous symptoms are the most prevalent in sensitised workers, and unlike nasal symptoms are significantly reduced when latex-avoidance measures are introduced. Ongoing nasal symptoms after intervention is instituted are probably due to other allergic sensitivities in latex-sensitised health care workers.

Understanding sampling: representativeness matters.

Sampling, or selecting a group of people to represent a whole population, lies at the heart of almost all research designs. There are many ways of going about this, each of which presents its own problems. The trick is to obtain a good-sized sample that is truly representative of the population as a whole.

Understanding screening: requirements for a successful programme.

Screening has generally been successful in identifying those at risk from disease. This success has led to the belief that screening in the general population is always a good thing. However, there are pitfalls which must be avoided if screening programmes are to achieve what is intended for them.

Does passive smoking increase the frequency of health service contacts in children with asthma?

BACKGROUND: Passive smoking is a major cause of respiratory morbidity in children. However, few studies give accurate estimates of the health effects of passive smoking in children with asthma using an objective measure of exposure. The effects of passive smoking using salivary cotinine levels to measure exposure were investigated. METHODS: A sample of 438 children aged 2-12 years with asthma who had a parent who smoked were recruited in Tayside and Fife, Scotland. Health service contacts for asthma, assessed from GP case records, were used as a proxy for morbidity. RESULTS: A weak U-shaped relationship was found between the salivary cotinine level and health service contacts for asthma: compared with low cotinine levels those with moderate cotinine levels had a reduced contact rate (relative rate (RR) = 0.91, 95% confidence interval (CI) 0.80 to 1.05), whereas high cotinine levels were associated with an increased rate of contact (RR = 1.19, 95% CI 1.05 to 1.37). In contrast, a strong association was seen with the amount the parent reported smoking in front of the child: the higher the level the fewer visits were made for asthma (RR for everyday exposure = 0.66, 95% CI 0.56 to 0.77). This effect was not seen for non-respiratory visits. Demographic factors, age of child, and number of children in the family all had a powerful effect on the number of visits for asthma. The parents' perception of asthma severity was associated with visit frequency independent of actual severity (derived from drug treatment). CONCLUSION: High levels of parental smoking in the home are associated with a reduction in health care contacts for asthma. This could be due to a lack of awareness of asthma symptoms among heavy smokers or a reluctance to visit the GP. Children with asthma who have parents who smoke heavily may not be receiving adequate management.

What do we know about the voluntary healthcare sector in Scotland?

OBJECTIVE: To document sources of information available to the National Health Service in Scotland (NHSiS) which relate to the health voluntary sector. DESIGN: Interrogation of the databases of the Charities Register in Scotland (CRIS) and Health Education Board for Scotland (HEBS) for information on health voluntary organisations and a retrospective review of information held on health voluntary organisations recently funded by health boards. SETTING: National Health Service in Scotland and the Scottish Council for Voluntary Organisations RESULTS: Nine hundred and fifty six health voluntary organisations in Scotland were registered with the CRIS database. Five hundred and forty five (57%) of these had annual incomes of less than 100,000 Pounds and two thirds of them (630) operated at a local level. Information on 3,106 health and support organisations was present on the HEBS database. In 1997-98 Scottish Health Boards grant funded 278 voluntary organisations. Eighty seven (31%) of these had information held on the CRIS database and another 87 (31%) with the HEBS database. Funding was much more likely to be given to organisations dealing with adult physical health and alcohol problems. Organisations dealing with specific diseases were less likely to be funded. Of the 87 funded organisations registered with CRIS, health boards typically contributed less than 10% of annual funding. CONCLUSIONS: Health planning decisions are made difficult by a deficiency of useful information on the existence, activities and financial positions of voluntary organisations. Construction of accurate and comprehensive national databases to inform these decisions would be expensive. However, the development of appropriate local databases by health boards and the voluntary sector would facilitate the development of a constructive partnership.

The natural history of chronic actinic dermatitis.

OBJECTIVE: To determine the prognosis for resolution of abnormal cutaneous photosensitivity in patients with chronic actinic dermatitis (also known as the photosensitivity dermatitis and actinic reticuloid syndrome). DESIGN: Historical cohort study involving follow-up of patients for up to 24 years from diagnosis. SETTING: A Scottish tertiary referral center for investigation of photodermatosis. PATIENTS: One hundred seventy-eight patients with chronic actinic dermatitis, 62% of a cohort of 285 living patients identified in the Photobiology Unit database. INTERVENTIONS: Recall for repeated clinical assessment and monochromator phototesting. All patients underwent patch testing when initially assessed; this was repeated at follow-up in a subgroup of patients. MAIN OUTCOME MEASURES: Resolution of abnormal photosensitivity, defined as clinical resolution and return of phototest responses to within normal population limits. In addition, possible prognostic factors for resolution of photosensitivity were examined. RESULTS: The probability of abnormal photosensitivity resolving by 10 years from diagnosis is 1 in 5. Particularly severe abnormal UV-B photosensitivity (minimal erythema dose at 305+/-5 nm half-maximum bandwidth, < or =5.6 mJ x cm(-2)) and the identification of separate contact allergens in 2 or more patch test batteries are predictors of a poorer prognosis for resolution. Loss of contact allergies was not associated with a different prognosis for photosensitivity resolution. Our findings probably underestimate the probability of resolution, as those referred to a tertiary referral center and willing to attend for follow-up may include a disproportionate number of severely affected patients. CONCLUSIONS: Newly diagnosed patients can be told that most of them will improve with appropriate UV/visible light and allergen avoidance and that there is hope that their photosensitivity will completely resolve.

Grant funding of health voluntary organizations by Scottish health boards.

The objective of this study was to identify grant funding of voluntary organizations by Scottish health boards in the financial year 1997-1998. Scottish health board financial commitments to voluntary organizations were surveyed. Fifteen health board Directors of Finance participated in the study. The outcome measures were relative and absolute commitments of grant expenditure to the voluntary sector by health boards in Scotland. Total expenditure of Scotland's 15 health boards ranged from zero to 764,910 pounds sterling. One health board did not support any voluntary organizations while the greatest number supported by an individual health board was 43. Of health boards that made grants to voluntary bodies the range of expenditure per head of resident population was 0.09 pounds sterling-3.00p pounds sterling. The average grant expenditure to voluntary organizations ranged from 1,839 pounds sterling to 30,308 pounds sterling. The most substantial funding fell to voluntary bodies within the fields of mental health, alcohol and community elderly care. However, there was substantial variation between health boards in whether these bodies were funded, and to what extent funding was given. In conclusions, health boards have conflicting practices in funding voluntary organizations. Although there may be some variation in the needs of voluntary bodies across health boards, this is unlikely to explain the scale of the variation. Further work is required to explain this phenomenon and to propose policies for the support of the voluntary sector by the National Health Service that are acceptable to both funders and providers of services.

Bias in case-control studies.

Case-control studies are largely used to explore differences between groups of individuals. They can identify potential risk factors associated with disease, or they can investigate patient behaviour, such as why some people do not attend for services. As such, case-control studies are often used to generate or test hypotheses about causal factors. Nonetheless, bias is always a danger in case-control studies, arising especially from the way in which study samples are selected or from the collection of retrospective data. Confounding also remains a problem. This short paper explores ways in which such flaws can be uncovered in published studies.

Reviewing audit: barriers and facilitating factors for effective clinical audit.

OBJECTIVE: To review the literature on the benefits and disadvantages of clinical and medical audit, and to assess the main facilitators and barriers to conducting the audit process. DESIGN: A comprehensive literature review was undertaken through a thorough review of Medline and CINAHL databases using the keywords of "audit", "audit of audits", and "evaluation of audits" and a handsearch of the indexes of relevant journals for key papers. RESULTS: Findings from 93 publications were reviewed. These ranged from single case studies of individual audit projects through retrospective reviews of departmental audit programmes to studies of interface projects between primary and secondary care. The studies reviewed incorporated the experiences of a wide variety of clinicians, from medical consultants to professionals allied to medicine and from those involved in unidisciplinary and multidisciplinary ventures. Perceived benefits of audit included improved communication among colleagues and other professional groups, improved patient care, increased professional satisfaction, and better administration. Some disadvantages of audit were perceived as diminished clinical ownership, fear of litigation, hierarchical and territorial suspicions, and professional isolation. The main barriers to clinical audit can be classified under five main headings. These are lack of resources, lack of expertise or advice in project design and analysis, problems between groups and group members, lack of an overall plan for audit, and organisational impediments. Key facilitating factors to audit were also identified: they included modern medical records systems, effective training, dedicated staff, protected time, structured programmes, and a shared dialogue between purchasers and providers. CONCLUSIONS: Clinical audit can be a valuable assistance to any programme which aims to improve the quality of health care and its delivery. Yet without a coherent strategy aimed at nurturing effective audits, valuable opportunities will be lost. Paying careful attention to the professional attitudes highlighted in this review may help audit to deliver on some of its promise.

What stops effective clinical audit? Reports from the front line.

Semi-structured interview were conducted with 145 clinicians from a variety of clinical backgrounds in twelve Trusts across three Scottish health boards. Questions examined barriers to the audit process and obstacles that impeded the implementation of changes in response to the audit findings as well as the need for resources to facilitate the audit activity. The most difficult part of the audit process was reported as data collection (32%) but almost half of respondents would have changed the way the audit was done with hindsight. The biggest barrier to doing the audit was perceived as lack of time (33%). Colleagues' attitudes posed the biggest obstacles to making changes as a result of the audit (26%). Few perceived the need for more resources but preferred focused and proactive support from managers and audit support staff. Trusts need to work harder at creating cultures where clinical audit is supported and actively encouraged.

Bias in cohort studies.

Cohort studies allow an exploration of patient change over time. They can provide information on the incidence of disease, prognosis (including patient satisfaction) and likely health-care resource use. Nonetheless, bias can be present in cohort studies in the way patients are selected and followed-up, the way measures are taken, or the way data are analysed. This short paper explores ways in which such flaws can be uncovered in published studies, so that their findings can be interpreted appropriately.