Overdiagnosis in organised mammography screening in Denmark. A comparative study

<p>Abstract</p> <p>Background</p> <p>Overdiagnosis in cancer screening is the detection of cancer lesions that would otherwise not have been detected. It is arguably the most important harm. We quantified overdiagnosis in the Danish mammography screening programme, which is uniquely suited for this purpose, as only 20% of the Danish population has been offered organised mammography screening over a long time-period.</p> <p>Methods</p> <p>We collected incidence rates of carcinoma in situ and invasive breast cancer in areas with and without screening over 13 years with screening (1991-2003), and 20 years before its introduction (1971-1990). We explored the incidence increase comparing unadjusted incidence rates and used Poisson regression analysis to compensate for the background incidence trend, variation in age distribution and geographical variation in incidence.</p> <p>Results</p> <p>For the screened age group, 50 to 69 years, we found an overdiagnosis of 35% when we compared unadjusted incidence rates for the screened and non-screened areas, but after compensating for a small decline in incidence in older, previously screened women. Our adjusted Poisson regression analysis indicated a relative risk of 1.40 (95% CI: 1.35-1.45) for the whole screening period, and a potential compensatory drop in older women of 0.90 (95% CI: 0.88-0.96), yielding an overdiagnosis of 33%, which we consider the most reliable estimate. The drop in previously screened women was only present in one of the two screened regions and was small in absolute numbers.</p> <p>Discussion</p> <p>One in four breast cancers diagnosed in the screened age group in the Danish screening programme is overdiagnosed. Our estimate for Denmark is lower than that for comparable countries, likely because of lower uptake, lower recall rates and lower detection rates of carcinoma in situ.</p

Amniotic fluid embolism incidence, risk factors and outcomes: a review and recommendations

<p>Abstract</p> <p>Background</p> <p>Amniotic fluid embolism (AFE) is a rare but severe complication of pregnancy. A recent systematic review highlighted apparent differences in the incidence, with studies estimating the incidence of AFE to be more than three times higher in North America than Europe. The aim of this study was to examine population-based regional or national data from five high-resource countries in order to investigate incidence, risk factors and outcomes of AFE and to investigate whether any variation identified could be ascribed to methodological differences between the studies.</p> <p>Methods</p> <p>We reviewed available data sources on the incidence of AFE in Australia, Canada, the Netherlands, the United Kingdom and the USA. Where information was available, the risk factors and outcomes of AFE were examined.</p> <p>Results</p> <p>The reported incidence of AFE ranged from 1.9 cases per 100 000 maternities (UK) to 6.1 per 100 000 maternities (Australia). There was a clear distinction between rates estimated using different methodologies. The lowest estimated incidence rates were obtained through validated case identification (range 1.9-2.5 cases per 100 000 maternities); rates obtained from retrospective analysis of population discharge databases were significantly higher (range 5.5-6.1 per 100 000 admissions with delivery diagnosis). Older maternal age and induction of labour were consistently associated with AFE.</p> <p>Conclusions</p> <p>Recommendation 1: Comparisons of AFE incidence estimates should be restricted to studies using similar methodology. The recommended approaches would be either population-based database studies using additional criteria to exclude false positive cases, or tailored data collection using existing specific population-based systems.</p> <p>Recommendation 2: Comparisons of AFE incidence between and within countries would be facilitated by development of an agreed case definition and an agreed set of criteria to minimise inclusion of false positive cases for database studies.</p> <p>Recommendation 3: Groups conducting detailed population-based studies on AFE should develop an agreed strategy to allow combined analysis of data obtained using consistent methodologies in order to identify potentially modifiable risk factors.</p> <p>Recommendation 4: Future specific studies on AFE should aim to collect information on management and longer-term outcomes for both mothers and infants in order to guide best practice, counselling and service planning.</p

Are benefits and harms in mammography screening given equal attention in scientific articles? A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The CONSORT statement specifies the need for a balanced presentation of both benefits and harms of medical interventions in trial reports. However, invitations to screening and newspaper articles often emphasize benefits and downplay or omit harms, and it is known that scientific articles can be influenced by conflicts of interest. We wanted to determine if a similar imbalance occurs in scientific articles on mammography screening and if it is related to author affiliation.</p> <p>Methods</p> <p>We searched PubMed in April 2005 for articles on mammography screening that mentioned a benefit or a harm and that were published in 2004 in English. Data extraction was performed by three independent investigators, two unblinded and one blinded for article contents, and author names and affiliation, as appropriate. The extracted data were compared and discrepancies resolved by two investigators in a combined analysis. We defined three groups of authors: (1) authors in specialties unrelated to mammography screening, (2) authors in screening-affiliated specialties (radiology or breast cancer surgery) who were not working with screening, or authors funded by cancer charities, and (3) authors (at least one) working directly with mammography screening programmes. We used a data extraction sheet with 17 items described as important benefits and harms in the 2002 WHO/IARC-report on breast cancer screening.</p> <p>Results</p> <p>We identified 854 articles, and 143 were eligible for the study. Most were original research. Benefits were mentioned more often than harms (96% vs 62%, P < 0.001). Fifty-five (38%) articles mentioned only benefits, whereas seven (5%) mentioned only harms (P < 0.001). Overdiagnosis was mentioned in 35 articles (24%), but was more often downplayed or rejected in articles that had authors working with screening, (6/15; 40%) compared with authors affiliated by specialty or funding (1/6; 17%), or authors unrelated with screening (1/14; 7%) (P = 0.03). Benefits in terms of reduced breast cancer mortality were mentioned in 109 (76%) articles, and was more often provided as a relative risk reduction than an absolute risk reduction, where quantified (45 articles (31%) versus 6 articles (3%) (P < 0.001)).</p> <p>Conclusion</p> <p>Scientific articles tend to emphasize the major benefits of mammography screening over its major harms. This imbalance is related to the authors' affiliation.</p

A survey of the quality of information leaflets on hayfever available from general practices and community pharmacies

Background: Hayfever affects at least one in 10 people. The majority of hayfever is managed in the community setting where the management options are pharmaceutical and behavioural. Hayfever medications are available over the counter and on prescription from the general practitioner. Patient information leaflets are published to augment the advice given and to promote self‐management, but these leaflets have rarely been subjected to critical review. Objective: To assess the quality of patient information leaflets written for people with hayfever and available from general practices and from community pharmacists. Method: A structured review of patient information leaflets about hayfever. During the peak grass pollen season copies of all leaflets available were collected from a random sample of community pharmacists and general practices in Wessex. The characteristics of the leaflet were recorded and the contents and presentation of each one was reviewed using the British Medical Association patient information appraisal system. Readability was assessed using the Simple Measure of Gobbledegook (SMOG). Two allergy‐accredited specialists assessed each leaflet for accuracy. Results: During the peak pollen season no leaflets were available in 30% of the Community Pharmacists and 23% general practices. In total, 38 different leaflets were identified. All the leaflets reviewed were written for adults. Forty‐seven percent of the leaflets had no publication date and one‐third of those dated were at least 5 years old. In general the leaflets scored highly on issues of presentation, but less than half contained information on the full range of management and treatment options, many being biased towards a single or limited range of interventions. Seventy‐nine percent leaflets were produced or sponsored by pharmaceutical companies and gave prominence to their own products. All the leaflets had readability scores requiring at least secondary education (SMOG score equal or greater than 9). At least one factual inaccuracy was identified in four‐fifths of leaflets. Conclusion: A large number of leaflets are published for people with hayfever, but they are of variable quality and not accessible to all patients because of limited distribution or high readability scores. If all patients are to benefit from written information the authors and publishers of leaflets need to follow published recommendations, especially with respect to content and readability. In the absence of a national public health information strategy or a body that systematically vets patient information materials, clinicians must pay attention to the quality of information provided for or obtained elsewhere by their patients

Believing in birth - choosing VBAC: the childbirth expectations of self-selected cohort of Australian women.

Aim. This study explored the childbirth expectations and knowledge of women who had experienced a caesarean and would prefer a vaginal birth in a subsequent pregnancy.Background. Vaginal birth after caesarean is considered best practice. However, in most western world countries, despite the inherent risks of caesarean for both mother and baby, the number of women labouring after a previous caesarean is declining.Methods. Newspaper advertisements were used to recruit Western Australian women who had experienced a caesarean. Thematic analysis was used to analyse the interview data collected from women who attempted a vaginal birth (n = 24), or stated they would choose this option, in a subsequent pregnancy (n = 11).Findings. For this cohort of women, their caesarean experience reinforced their previously held expectations about birthing naturally. The women held strong views about the importance of working with their bodies to achieve a vaginal birth, which was considered an integral part of being a woman and mother. Positive support from family and friends and a reluctance to undergo another caesarean was also influential. Women articulated the risks of caesarean and considered vaginal birth enhanced the health and well-being of the mother and baby, promoted maternal infant connection and the eased transition to motherhood.Conclusion. This study documents how the importance of birth, as a significant life event, remained the focus of these women's childbirth expectations influencing future decisions on birth mode and mediating against the 'pressure' of medical discourse promoting caesarean.Relevance to clinical practice. Knowledge and appreciation of the multiple dimensions that contribute to women's decision after a caesarean provides valuable information on which service providers and researchers can draw as they investigate interventions that enhance the uptake and success of women birthing vaginally after a caserean