Test, episode, and programme sensitivities of screening for colorectal cancer as a public health policy in Finland: experimental design

Objectives To report the sensitivities of the faecal occult blood test, screening episode, and screening programme for colorectal cancer and the benefits of applying a randomised design at the implementation phase of a new public health policy

Challenges in evaluation of screening for gastric cancer among men based on nonrandomized design

Background: Objective was to quantify biases in screening for gastric cancer when comparing attenders to nonattenders using serum pepsinogen I (SPGI) level as primary test.Methods: In mid 1990s, all men aged 51-65 years from two Finnish cities were invited to SPGI screening. Mortality and premature mortality in attenders were compared to nonattenders. Efficacy of screening was studied by 15 years' follow-up of standardized mortality ratio (SMR) and potential years of life lost (PYLL) due to gastric cancer. Bias due to selective attendance was quantified using corrective coefficients based on total cancer incidence and mortality, and gastric cancer-specific incidence and mortality for total population and nonattenders.Results: In 1994-1996, men aged 51-65 years (16,872) were invited to SPGI assay and 12,175 men (72%) attended. SPGI was 25 microg/l or less in 610 (5%) men, indicating severe atrophic gastritis (AG). Post-screening gastroscopy was performed to 435 men with low SPGI. Of these, 168 men were referred for treatment due to abnormal focal lesions. Attributable proportions in reductions of SMR and PYLL from gastric cancer due to screening were 59% and 67%. After correcting for selective participation, attributable proportions were reduced to 23% and 39%.Conclusions: Biomarker screening by low SPGI among middle-aged men followed by upper gastrointestinal endoscopy decreased long-term and premature mortality due to gastric cancer. However, in spite of methodological corrections done, the results do not justify any firm conclusions or recommend general screening programs. Randomized trials are warranted for this purpose.Peer reviewe

Oesophageal cancer incidence in 20-year follow-up in a population-based sample of 12 000 middle-age men with or without Helicobacter pylori infection in Finland

Non peer reviewe

Kokeelliset tutkimukset sosiaalilääketieteessä

Tausta. Koe on kliinisen tutkimuksen perusasetelma, mutta vähemmän käytetty sosiaalilääketieteessä. Kokeellinen tutkimus. Tutkijan määräämä interventio määrittää tutkimuksen kokeelliseksi. Vertailukelpoisuuden vuoksi pyritään satunnaistamiseen ryhmiin jaossa. Kokeelliset tutkimukset on usein jaettu mekanistiseen ja käytännölliseen. Kokeellisella terveydenhuoltotutkimuksella (KTT) tarkoitamme tutkimusta, joka asettuu käytännöllisen tutkimuksen ja kehittämisinterventioiden välimaastoon. KTT:tä ja sen alatyyppejä on kutsuttu useilla nimillä. Tyypillisiä piirteitä ovat tutkimuksen tilannesidonnaisuus, ryhmä tai organisaatio tutkimusyksikkönä ja havaintojen synty sivutuotteena. KTT poikkeaa kliinisistä kokeista eettiseltä normistoltaan, hallinnoltaan, toteutukseltaan ja rahoitukseltaan. Jatkossa. Suomessa on hyvät edellytykset terveydenhuollon kokeellisen tutkimukseen, mutta tarvitaan opetusta, asenteisiin vaikuttamista sekä tutkimussäädösten ja niiden tulkinnan muutosta. Kustannuksia voi pienentää integroimalla tutkimukset palvelujärjestelmään ja keräämällä lopputulostiedot rutiinitiedostoista

Tobacco use or body mass - do they predict tuberculosis mortality in Mumbai, India? Results from a population-based cohort study

Tobacco use and under-nutrition are major public health concerns and tuberculosis is a major cause of morbidity and mortality in India. Using a cohort of 148,173 persons (recruited 1991–1997 and followed-up 1997–2003) the joint effects of tobacco use and BMI on tuberculosis mortality was studied. Tobacco use in any form and low-BMI had joint effect on tuberculosis mortality and the interaction effect was synergistic in men and antagonistic in women. Self-reported tuberculosis was associated with increased risk of tuberculosis mortality. In contrast, no such association was observed for self-reported diabetes persons. The risk pattern remained unchanged even after excluding tuberculosis deaths occurred within 1st two years of follow-up. This study highlights importance of age consideration of individual while excluding early deaths. Around 27% male tuberculosis deaths were attributable to their being underweight and smoker, while 22% male and 37% female deaths were attributable to their being underweight and smokeless tobacco user.Public Library of Science open acces

Rate of cervical cancer, severe intraepithelial neoplasia, and adenocarcinoma in situ in primary HPV DNA screening with cytology triage: randomised study within organised screening programme

Objective To assess the performance and impact of primary human papillomavirus (HPV) DNA screening with cytology triage compared with conventional cytology on cervical cancer and severe pre-cancerous lesions

Alternative technologies in cervical cancer screening: a randomised evaluation trial

BACKGROUND: Cervical cancer screening programmes have markedly reduced the incidence and mortality rates of the disease. A substantial amount of deaths from the disease could be prevented further by organised screening programmes or improving currently running programmes. METHODS/DESIGN: We present here a randomised evaluation trial design integrated to the Finnish cervical cancer screening programme, in order to evaluate renewal of the programme using emerging technological alternatives. The main aim of the evaluation is to assess screening effectiveness, using subsequent cancers as the outcome and screen-detected pre-cancers as surrogates. For the time being, approximately 863,000 women have been allocated to automation-assisted cytology, human papillomavirus (HPV) DNA testing, or to conventional cytology within the organised screening programme. Follow-up results on subsequent cervical cancers will become available during 2007–2015. DISCUSSION: Large-scale randomised trials are useful to clarify effectiveness and cost-effectiveness issues of the most important technological alternatives in the screening programmes for cervical cancer

Who wants to join preventive trials? – Experience from the Estonian Postmenopausal Hormone Therapy Trial [ISRCTN35338757]

BACKGROUND: The interest of patients in participating in randomized clinical trials involving treatments has been widely studied, but there has been much less research on interest in preventive trials. The objective of this study was to find out how many women would be interested in a trial involving postmenopausal hormone therapy (PHT) and how the women's background characteristics and opinions correlated to their interest. METHODS: The data come from recruitment questionnaires (n = 2000) sent to women in Estonia in 1998. A random sample of women aged 45 to 64 was drawn from the Population Registry. The trial is a two-group randomized trial comparing estrogen-progestogen therapy with placebo or no drugs. A brief description of the study was attached to the questionnaires. Women were not told at this stage of the recruitment which group they would be assigned to, however, they were told of the chance to receive either hormone, placebo or no treatment. RESULTS: After two reminders, 1312 women (66%) responded. Eleven percent of the women approached (17% of the respondents) were interested in joining the trial, and 8% wanted more information before deciding. When the 225 women who stated clearly that they were interested in joining and the 553 women who said they were not interested were compared, it was found that interested women were younger and, adjusting for age, that more had given birth; in other respects, the sociodemographic characteristics and health habits of the interested women were similar to those of the non-interested women. The interested women had made more use of more health services, calcium preparations and PHT, they were more often overweight, and more had chronic diseases and reported symptoms. Interested women's opinions on the menopause were more negative, and they favoured PHT more than the non-interested women. CONCLUSION: Unlike the situation described in previous reports on preventive trials, in this case Estonian women interested in participating in a PHT trial were not healthier than other women. This suggests that trials involving PHT are more similar to treatment trials than to preventive trials. In a randomized controlled trial, more information should be obtained from those women who decline to participate

Results from a blind and a non-blind randomised trial run in parallel: experience from the Estonian Postmenopausal Hormone Therapy (EPHT) Trial

<p>Abstract</p> <p>Background</p> <p>The Estonian Postmenopausal Hormone Therapy (EPHT) Trial assigned 4170 potential participants prior to recruitment to blind or non-blind hormone therapy (HT), with placebo or non-treatment the respective alternatives. Before having to decide on participation, women were told whether they had been randomised to the blind or non-blind trial. Eligible women who were still willing to join the trial were recruited. After recruitment participants in the non-blind trial (N = 1001) received open-label HT or no treatment, participants in the blind trial (N = 777) remained blinded until the end of the trial. The aim of this paper is to analyse the effect of blinding on internal and external validity of trial outcomes.</p> <p>Methods</p> <p>Effect of blinding was calculated as the hazard ratio of selected chronic diseases, total mortality and all outcomes. For analysing the effect of blinding on external validity, the hazard ratios from women recruited to the placebo arm and to the non-treatment arm were compared with those not recruited; for analysing the effect of blinding on internal validity, the hazard ratios from the blind trial were compared with those from the non-blind trial.</p> <p>Results</p> <p>The women recruited to the placebo arm had less cerebrovascular disease events (HR 0.43; 95% CI: 0.26-0.71) and all outcomes combined (HR 0.76; 95% CI: 0.63-0.91) than those who were not recruited. Among women recruited or not recruited to the non-treatment arm, no differences were observed for any of the outcomes studied.</p> <p>Among women recruited to the trial, the risk for coronary heart disease events (HR 0.77; 95% CI: 0.64-0.93), cerebrovascular disease events (HR 0.66; 95%CI: 0.47-0.92), and all outcomes combined (HR 0.82; 95% CI: 0.72-0.94) was smaller among participants in the blind trial than in the non-blind trial. There was no difference between the blind and the non-blind trial for total cancer (HR 0.95; 95% CI: 0.64-1.42), bone fractures (0.93; 95% CI: 0.74-1.16), and total mortality (HR 1.03; 95% CI: 0.53-1.98).</p> <p>Conclusions</p> <p>The results from blind and non-blind trials may differ, even if the target population is the same. Blinding may influence both internal and external validity. The effect of blinding may vary for different outcome events.</p> <p>Trial registration</p> <p>[<a href="http://www.controlled-trials.com/ISRCTN35338757">ISRCTN35338757</a>]</p