European guidelines for quality assurance in colorectal cancer screening and diagnosis: overview and introduction to the full supplement publication.

Population-based screening for early detection and treatment of colorectal cancer (CRC) and precursor lesions, using evidence-based methods, can be effective in populations with a significant burden of the disease provided the services are of high quality. Multidisciplinary, evidence-based guidelines for quality assurance in CRC screening and diagnosis have been developed by experts in a project co-financed by the European Union. The 450-page guidelines were published in book format by the European Commission in 2010.  They include 10 chapters and over 250 recommendations, individually graded according to the strength of the recommendation and the supporting evidence. Adoption of the recommendations can improve and maintain the quality and effectiveness of an entire screening process, including identification and invitation of the target population, diagnosis and management of the disease and appropriate surveillance in people with detected lesions. To make the principles, recommendations and standards in the guidelines known to a wider professional and scientific community and to facilitate their use in the scientific literature, the original content is presented in journal format in an open-access Supplement of Endoscopy. The editors have prepared the present overview to inform readers of the comprehensive scope and content of the guidelines.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Evaluation and interpretation of screening outcomes.

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on evaluation and interpretation of screening outcomes includes 20 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of the screening process, including multi-disciplinary diagnosis and management of the disease.

Modelling the effect of breast cancer screening on related mortality using French data.

INTRODUCTION: This study aimed at modelling the effect of organized breast cancer screening on mortality in France. It combined results from a Markov model for breast cancer progression, to predict number of cases by node status, and from relative survival analyses, to predict deaths. The method estimated the relative risk of mortality at 8 years, in women aged 50-69, between a population screened every two years and a reference population. METHODS: Analyses concerned cases diagnosed between 1990 and 1996, with a follow-up up to 2004 for the vital status. Markov models analysed data from 3 screening programs (300,000 mammographies) and took into account opportunistic screening among participants to avoid bias in parameter's estimates. We used survival data from cancers in the general population (n=918, 7 cancer registries) and from screened cancers (n=565, 3 cancer registries), after excluding a subgroup of screened cases with a particularly high survival. Sensitivity analyses were performed. RESULTS: Markov model main analysis lacked of fit in two out of three districts. Fit was improved in stratified analyses by age or district, though some lack of fit persisted in two districts. Assuming 10% or 20% overdiagnosed screened cancers, mortality reduction was estimated as 23% (95% CI: 4, 38%) and 19% (CI: -3, 35%) respectively. Results were highly sensitive to the exclusion in the screened cancers survival analysis. Conversely, RR estimates varied moderately according to the Markov model parameters used (stratified by age or district). CONCLUSION: The study aimed at estimating the effect of screening in a screened population compared to an unscreened control group. Such a control group does not exist in France, and we used a general population contaminated by opportunistic screening to provide a conservative estimate. Conservative choices were systematically adopted to avoid favourable estimates. A selection bias might however affect the estimates, though it should be moderate because extreme social classes are under-represented among participants. This modelling provided broad estimates for the effect of organized biennial screening in France in the early nineteen-nineties. Results will be strengthened with longer follow-up.

[Breast cancer screening: are results of French and international programmes comparable?]. / Dépistage organisé des Cancers du Sein: peut-on comparer les résultats du programme français aux résultats internationaux?

Full coverage of the national breast cancer screening programme was obtained in 2004. The new protocol was published in 2001. It changed the organisation implemented since 1994 for a better fit with the French decentralized health care system. Consequences on health results were analysed explaining related medical and sociological factors. The main change was the rate of positive mammograms which differed from the recall rate given in the European recommendations. With the new protocol the rate of assessments more than doubled: 6% in year 2000 and 14% in 2003. International comparisons are difficult since each country has a different organisation. Moreover the coexistence in France of organized screening and opportunistic screening causes a complex issue for evaluation of impact indicators of this population based programme.

International comparison of performance measures for screening mammography: can it be done?

OBJECTIVE: Published screening mammography performance measures vary across countries. An inter-national study was undertaken to assess the comparability of two performance measures: the recall rate and positive predictive value (PPV). These measures were selected because they do not require identification of all cancers in the screening population, which is not always possible. SETTING: The screening mammography programs or data registries in 25 member countries of the International Breast Cancer Screening Network (IBSN). METHODS: In 1999 an assessment form was distributed to IBSN country representatives in order to obtain information on how screening mammography was performed and what specific data related to recall rates and PPV were collected. Participating countries were then asked to provide data to allow calculation of recall rates, PPV and cancer detection rates for screening mammography by age group for women screened in the period 1997-1999. RESULTS: Twenty-two countries completed the assessment form and 14 countries provided performance data. Differences in screening mammography delivery and data collection were evident. For most countries, recall rates were higher for initial than for subsequent mammograms. There was no consistent relationship of initial to subsequent PPV, although PPV generally decreased as the recall rate increased. Recall rates decreased with increasing age, while PPV increased as age increased. CONCLUSION: Similar patterns for mammography performance measures were evident across countries.However, the development of a more standardized approach to defining and collecting data would allow more valid international comparisons, with the potential to optimize mammography performance. At present, international comparisons of performance should be made with caution due to differences in defining and collecting mammography data.

Knowledge of HIV serostatus and preventive behaviour among European injecting drug users: second study. European Community Study Group on HIV in Injecting Drug Users.

The objective of the study was to analyse the effect of knowledge of HIV serostatus on behaviours preventing the acquisition or transmission of HIV among European IDU, and to compare results with a previous similar study conducted 3 years before. Data were gathered in 1992-1993 during a retrospective multicentre cross-sectional study of IDU recruited in 11 European countries, in specialized centers and on the street. We compared, between groups with different HIV serological status (IDU who knew well before their HIV-positive serological status, IDU who knew their HIV-negative serostatus and IDU who did not know before their serological status), the respective proportions of IDU who reported that, during the six months prior to interview, (1) always used condoms, (2) never gave their used injecting equipment to other IDU, (3) always injected drugs safely. We only included IDU who had known their serological status for at least six months prior to interview. Results were compared to the similar survey conducted in 1990. From 2171 IDU recruited, data of 1334 IDU were included in the analysis. Compared with IDU who did not know their HIV serostatus, only IDU knowing their HIV-positive serostatus used condoms significantly more often (37% compared to 15%, rate ratio (RR): 2.4; 95% confidence interval (CI): 1.8-2.3) and never gave their used injecting equipment to other IDU (69% compared to 53%, RR: 1.3; 95% CI: 1.2-1.4). In comparison with the 1990 study, only condom use significantly improved and only for IDU who knew their HIV-negative serostatus (13% compared to 9%, RR: 1.6; 95% CI: 1.1-2.3). This study confirms among European IDU the relation between knowing own HIV serological status to preventive behaviours. However, there were only minor improvements between 1990 and 1992-1993, indicating that prevention of HIV transmission among IDU must be reinforced.

Factors associated with extrapulmonary tuberculosis as an AIDS-defining disease in Europe. The Coordinators of AIDS surveillance in Austria, Belgium, France, Germany, Italy, Portugal, Switzerland, United Kingdom and the city of Amsterdam.

SETTING: Western Europe: 8 countries and the city of Amsterdam. OBJECTIVE: To identify factors associated with extrapulmonary tuberculosis (EPTB) at AIDS diagnosis among adult AIDS patients. DESIGN: The proportion of AIDS case diagnosed between January 1988 and June 1992 with EPTB was analysed by age, gender, year of diagnosis, country and HIV transmission category. Multiple logistic regression was performed separately for patients infected through heterosexual contact who were likely to originate from Africa or the Caribbean (heterosexual subgroup 1), and for other patients. RESULTS: The overall proportion with EPTB was 4.6% and remained stable between 1988 and 1992. It differed significantly by country (from 2.4% in the United Kingdom to 24.7% in Portugal) and by transmission category (2.7% among homo/bisexuals, 5.8% among injecting drug users, 13.6% among heterosexual subgroup 1). In multivariate analysis, the risk of EPTB was independently associated with younger age and male gender. Among patients other than from heterosexual subgroup 1, country and transmission category were also independent predictors of EPTB at AIDS diagnosis. CONCLUSION: The risk of presenting EPTB as an AIDS-defining disease is not homogeneous within Europe. Results suggest an increased risk of tuberculosis in specific groups of HIV-infected persons (persons originating from sub-Saharan Africa, injecting drug users) and a potential role of recent Mycobacterium tuberculosis infection among younger patients.

Incubation period of vertically acquired AIDS in Europe before widespread use of prophylactic therapies.

European surveillance data on vertically acquired (VA) AIDS cases were used to investigate the incubation period of AIDS in the absence of widespread prophylactic treatment and to assess the uncertainty associated with parametric estimates based on retrospective data. Nonparametric and parametric analyses, taking into account the effects of data truncation, were based on a total of 792 children diagnosed with AIDS between July, 1982, and June, 1990, inclusive. Among HIV-infected children who develop AIDS within 8 years, the nonparametric estimate of the median age at diagnosis was 34 months. If 20% of children are assumed to develop AIDS by the age of 1 year (a plausible estimate on the basis of published cohort data), the estimated median among all maternally HIV-infected children is 4.4 years, with 26% of children expected to remain AIDS free by 8 years of age. Results from the parametric (double Weibull) model support the hypothesis of a bimodal distribution, with a subgroup of children progressing rapidly to AIDS at a median age of approximately 5 months. However, neither the relative size of this group nor the median age at which AIDS develops in the remaining children can yet be estimated with any reasonable precision.

Recent trends in Pneumocystis carinii pneumonia as AIDS-defining disease in nine European countries. Coordinators for AIDS Surveillance.

We analyzed the proportion of AIDS cases with Pneumocystis carinii pneumonia (PCP) at diagnosis among the 43,198 adult AIDS cases diagnosed since January 1988 and reported by June 1992 in Austria, Belgium, France, Germany, Italy, Portugal, Switzerland, United Kingdom, and the city of Amsterdam. In multivariate analysis, the risk of having PCP at AIDS diagnosis decreased slightly with increasing age and was strongly associated with country of diagnosis, transmission category, and year of diagnosis, but not with gender. Since 1989, the proportion of AIDS cases with PCP decreased significantly among homosexual and bisexual men in five of the nine countries examined and among injecting drug users in four of seven countries. In three countries with sufficient data for analysis, no significant decrease was seen among heterosexual patients with a partner originating from a country where heterosexual transmission is common (i.e., Africa/Caribbean). Among other heterosexual patients, a significant decreasing trend was demonstrated in only one of six countries analyzed. For all countries combined, the decrease was significant among hemophiliacs and of borderline significance among transfusion recipients. Results suggest that medical management before AIDS diagnosis is not homogeneous among all human immunodeficiency virus (HIV)-infected persons in Europe. Efforts should be made to provide better information on the potential benefit of early HIV testing and to facilitate the use of preventive treatments.

Knowledge, attitudes and beliefs of European injecting drug users concerning preventive measures for HIV.

Strategies for controlling the HIV epidemic include education and information campaigns for intravenous drug users (IDUs), as for all high-risk groups, and the provision of various public health measures and treatment. These can only be effective if the IDU is aware of them and has a favourable image of them. A study of 2330 IDUs in 12 European countries recorded awareness and opinions of various categories of measures and institutions. Of all measures, those mentioned most often related to availability of new injecting equipment; specifically unrestricted sales in pharmacies and needle exchanges, which were also thought to be more useful than anything else. Prompted awareness of rehabilitative institutions was well over 90% in most countries, but up to a quarter of IDUs did not trust them and up to one fifth did not think that they were useful. There appears to be a general need for more effective communication with IDUs to improve the image of the services available.

Factors associated with HIV seropositivity in European injecting drug users. The European Community Study Group on HIV in Injecting Drug Users.

OBJECTIVE: To study factors associated with HIV seropositivity among European injecting drug users (IDU). METHODS: Data on behavioural and other factors potentially associated with HIV status were collected retrospectively by personal interview with IDU (n = 2330) in a multicentre cross-sectional survey conducted in 12 European countries from 1989 to 1990. HIV status tested at the time of the survey was examined in relation to demographic data, history of imprisonment, travel to foreign countries, high-risk drug-using practices in the previous 6 months (re-using other IDU's injecting equipment without effective disinfection) and high-risk sexual behaviour in the last 6 months (multiple partners, unless none was IDU and condoms were always used). Analysis excluded IDU who claimed to be seropositive from previous testing. RESULTS: Imprisonment was significantly associated with current HIV status [odds ratio (OR), 1.70; 95% confidence interval (CI), 1.2-2.87]. High-risk drug-use practices were significantly associated with current HIV status in respondents not previously tested (OR, 2.86; 95% CI, 1.09-7.35) but not in respondents claiming to be seronegative. No significant association was found for high-risk sexual behaviour. CONCLUSIONS: Our experience supports the validity of retrospective investigation of behaviour in a population that is notoriously difficult to study. However, any interpretation of the apparently different associations of HIV status with high-risk sexual behaviour and high-risk drug-use practices must consider that factors tending to attenuate the correlations may operate differently in these two areas.

Knowledge of HIV serostatus and preventive behaviour among European injecting drug users. The European Community Study Group on HIV in Injecting Drug Users.

OBJECTIVE: To study the effect of knowledge of HIV serostatus on behaviour for preventing the acquisition or transmission of HIV among European injecting drug users (IDU). METHODS: Data on behaviour and prior knowledge of HIV status were gathered during a multicentre cross-sectional survey of 200 European IDU recruited in 12 European countries in 1990. The respective proportions of IDU who (1) used condoms, (2) did not give their used injecting equipment to other IDU and (3) injected drugs safely (ether did not re-use other IDU's equipment or re-used it only after disinfection with bleach, alcohol or boiling water during the 6 months preceding interview were compared according to whether they knew their HIV serostatus for at least 6 months prior to interview. RESULTS: In comparison with IDU who had never been tested, IDU who knew that they were HIV-seropositive were more likely to always use condoms [rate ratio (RR) = 3.1; 95% confidence interval (CI), 2.3-4.2] and never gave their used equipment to other IDU (RR = 1.3; 95% CI, 1.2-1.5), but did not differ with regard to safe injecting practices (RR = 1.0; 95% CI, 0.9-1.1). Compared with IDU who had never been tested, IDU with a negative test tended to inject drugs safely more often (RR = 1.1; 95% CI, 1.02-1.2). There was no significant difference in condom use (RR = 0.7; 95% CI, 0.5-1.1). CONCLUSION: These results indicate that the knowledge of HIV serostatus may help to reduce HIV transmission from HIV-positive IDU to others through safer injecting and sexual behaviour. However, for HIV-negative IDU safer injecting behaviour appears to be better accepted than safer sexual behaviour.

The epidemiology of AIDS-associated non-Hodgkin's lymphoma in the World Health Organization European Region.

This paper describes the epidemiology of AIDS-associated non-Hodgkin's lymphoma (NHL) in the World Health Organization (WHO) European Region. Data, collected by the WHO Collaborating Centre on AIDS in Paris, France, were derived from the national AIDS surveillance systems of 21 countries. Among 53,042 cases reported as of the end of June 1991, 1,617 (3.0%) had NHL as the presenting clinical manifestation of AIDS. The proportion of cases presenting with NHL ranged from 1.1% in children infected perinatally to 3.9% among haemophiliacs. In comparison with intravenous drug users (IVDUs) (2.6% of whom had NHL), a moderate excess was found among homosexual or bisexual men (odds ratio - OR -:1.2, 95% confidence interval - CI -:1.0-1.3). Over time, the proportion of NHL was constant, but whereas among homosexual or bisexual men the frequency of NHL as AIDS-indicator disease significantly increased (9.7% per year), among IVDUs a significant downward trend emerged (17.1% per year). In respect to age, two peaks of NHL were seen at the age groups 10-19 (3.8%) and 50-59 (4.3%). The proportion of AIDS-associated NHL significantly increased with increasing age among homosexual and bisexual men and heterosexuals whereas it decreased among IVDUs. All these differences, however, have to be interpreted cautiously on account of the limitations of the reporting systems.

Transfusion-associated AIDS cases in Europe: estimation of the incubation period distribution and prediction of future cases.

European data on transfusion-associated (TA) AIDS cases reported by December 31, 1989 have been analyzed using both parametric and nonparametric methods. Parametric estimates of the median incubation period of TA AIDS in adults vary from 6.5 to 11 years according to the type of distribution assumed (Weibull or gamma) and the latest year of diagnosis included (1987 or 1988). The latter finding may reflect a lengthening of the incubation period due to increasing treatment of HIV-infected patients prior to the development of AIDS. It is predicted that, by the end of 1991, between 2,000 and 3,000 cases of AIDS will have been diagnosed in Europe among adults infected by transfusion between 1978 and 1985 (when systematic screening of donated blood was introduced in most western countries). It is not possible, however, to predict how many further cases may arise among those transfused more recently in countries in which screening was introduced at a later date.