Reliability of case definitions for public health surveillance assessed by Round-Robin test methodology

BACKGROUND: Case definitions have been recognized to be important elements of public health surveillance systems. They are to assure comparability and consistency of surveillance data and have crucial impact on the sensitivity and the positive predictive value of a surveillance system. The reliability of case definitions has rarely been investigated systematically. METHODS: We conducted a Round-Robin test by asking all 425 local health departments (LHD) and the 16 state health departments (SHD) in Germany to classify a selection of 68 case examples using case definitions. By multivariate analysis we investigated factors linked to classification agreement with a gold standard, which was defined by an expert panel. RESULTS: A total of 7870 classifications were done by 396 LHD (93%) and all SHD. Reporting sensitivity was 90.0%, positive predictive value 76.6%. Polio case examples had the lowest reporting precision, salmonellosis case examples the highest (OR = 0.008; CI: 0.005–0.013). Case definitions with a check-list format of clinical criteria resulted in higher reporting precision than case definitions with a narrative description (OR = 3.08; CI: 2.47–3.83). Reporting precision was higher among SHD compared to LHD (OR = 1.52; CI: 1.14–2.02). CONCLUSION: Our findings led to a systematic revision of the German case definitions and build the basis for general recommendations for the creation of case definitions. These include, among others, that testable yes/no criteria in a check-list format is likely to improve reliability, and that software used for data transmission should be designed in strict accordance with the case definitions. The findings of this study are largely applicable to case definitions in many other countries or international networks as they share the same structural and editorial characteristics of the case definitions evaluated in this study before their revision

Self reported health status, and health service contact, of illicit drug users aged 50 and over: a qualitative interview study in Merseyside, United Kingdom

<p><b>Background:</b> The populations of industrialised countries are ageing; as this occurs, those who continue to use alcohol and illicit drugs age also. While alcohol use among older people is well documented, use of illicit drugs continues to be perceived as behaviour of young people and is a neglected area of research. This is the first published qualitative research on the experiences of older drug users in the United Kingdom.</p> <p><b>Methods:</b> Semi-structured interviews were conducted in Merseyside, in 2008, with drug users aged 50 and over recruited through drug treatment services. Interviews were recorded and transcribed and analysed thematically. Only health status and health service contact are reported here.</p> <p><b>Results:</b> Nine men and one woman were interviewed (age range: 54 to 61 years); all but one had been using drugs continuously or intermittently for at least 30 years. Interviewees exhibited high levels of physical and mental morbidity; hepatitis C was particularly prevalent. Injecting-related damage to arm veins resulted in interviewees switching to riskier injecting practices. Poor mental health was evident and interviewees described their lives as depressing. The death of drug-using friends was a common theme and social isolation was apparent. Interviewees also described a deterioration of memory. Generic healthcare was not always perceived as optimal, while issues relating to drug specific services were similar to those arising among younger cohorts of drug users, for example, complaints about inadequate doses of prescribed medication.</p> <p><b>Conclusion:</b> The concurrent effects of drug use and ageing are not well understood but are thought to exacerbate, or accelerate the onset of, medical conditions which are more prevalent in older age. Here, interviewees had poor physical and mental health but low expectations of health services. Older drug users who are not in contact with services are likely to have greater unmet needs. The number of drug users aged 50 and over is increasing in Europe and America; this group represent a vulnerable, and in Europe, a largely hidden population. Further work to evaluate the impact of this change in demography is urgently needed.</p&gt

The management of Legionnaires' disease in Ireland

Available from British Library Document Supply Centre- DSC:m03/11356 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

National guidelines for the prevention of nosocomial invasive aspergillosis during construction/renovation activities

Available from British Library Document Supply Centre- DSC:m03/11357 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Different transmission patterns in the early stages of the influenza A(H1N1)v pandemic: a comparative analysis of 12 European countries.

Following the emergence of a novel strain of influenza A(H1N1) in Mexico and the United States in April 2009, its epidemiology in Europe during the summer was limited to sporadic and localised outbreaks. Only the United Kingdom experienced widespread transmission declining with school holidays in late July. Using statistical modelling where applicable we explored the following causes that could explain this surprising difference in transmission dynamics: extinction by chance, differences in the susceptibility profile, age distribution of the imported cases, differences in contact patterns, mitigation strategies, school holidays and weather patterns. No single factor was able to explain the differences sufficiently. Hence an additive mixed model was used to model the country-specific weekly estimates of the effective reproductive number using the extinction probability, school holidays and weather patterns as explanatory variables. The average extinction probability, its trend and the trend in absolute humidity were found to be significantly negatively correlated with the effective reproduction number - although they could only explain about 3% of the variability in the model. By comparing the initial epidemiology of influenza A (H1N1) across different European countries, our analysis was able to uncover a possible role for the timing of importations (extinction probability), mixing patterns and the absolute humidity as underlying factors. However, much uncertainty remains. With better information on the role of these epidemiological factors, the control of influenza could be improved