Effectiveness of early detection on breast cancer mortality reduction in Catalonia (Spain)

Background: At present, it is complicated to use screening trials to determine the optimal age intervals and periodicities of breast cancer early detection. Mathematical models are an alternative that has been widely used. The aim of this study was to estimate the effect of different breast cancer early detection strategies in Catalonia (Spain), in terms of breast cancer mortality reduction (MR) and years of life gained (YLG), using the stochastic models developed by Lee and Zelen (LZ). Methods: We used the LZ model to estimate the cumulative probability of death for a cohort exposed to different screening strategies after T years of follow-up. We also obtained the cumulative probability of death for a cohort with no screening. These probabilities were used to estimate the possible breast cancer MR and YLG by age, period and cohort of birth. The inputs of the model were: incidence of, mortality from and survival after breast cancer, mortality from other causes, distribution of breast cancer stages at diagnosis and sensitivity of mammography. The outputs were relative breast cancer MR and YLG. Results: Relative breast cancer MR varied from 20% for biennial exams in the 50 to 69 age interval to 30% for annual exams in the 40 to 74 age interval. When strategies differ in periodicity but not in the age interval of exams, biennial screening achieved almost 80% of the annual screening MR. In contrast to MR, the effect on YLG of extending screening from 69 to 74 years of age was smaller than the effect of extending the screening from 50 to 45 or 40 years. Conclusion: In this study we have obtained a measure of the effect of breast cancer screening in terms of mortality and years of life gained. The Lee and Zelen mathematical models have been very useful for assessing the impact of different modalities of early detection on MR and YLG in Catalonia (Spain)

Ischemic stroke incidence in Santa Coloma de Gramenet (ISISCOG), Spain. A community-based study

<p>Abstract</p> <p>Background</p> <p>In Spain, stroke is one of the major causes of death and the main cause of severe disability in people over 65 years. We analyzed the incidence of ischemic stroke, stroke subtypes, case fatality and disability at 90 days after the event in a Spanish population.</p> <p>Methods</p> <p>A prospective community-based register of ischemic strokes was established in Santa Coloma de Gramenet (Barcelona) [116,220 inhabitants of all ages, according to the municipal census of December 31,2001], from January 1 to December 31, 2003.</p> <p>Standard definitions and case finding methods were used to identify all cases in all age groups. Every patient underwent a complete clinical evaluation and systematic tests including neuroimaging (CT/MRI) and vascular studies (carotid duplex ultrasound intra and extracranial and MR angiography).</p> <p>Results</p> <p>Over a one year period, 196 ischemic strokes were registered [107 men; median age = 76 years (range 39–98)], being the first event in 159 patients (81.1%) and a recurrent stroke in 37 (18.9%). After age-adjustment to the European population, the incidence of ischemic stroke per 100,000 inhabitants was 172 (95% CI, 148–196); 219 (176–261) in men and 133 (105–160) in women, with an annual incidence for first ischemic stroke of 139 (118–161); 165 (128–201) in men and 115 (89–140) in women. The incidence of stroke increased with age.</p> <p>Stroke subtypes (TOAST classification criteria) were lacunar in 28.8%, atherothrombotic in 18.6%, cardioembolic in 26.6% and undetermined in 26.0% of patients. At 90 days, the case-fatality was 12%, and among survivors, moderate-to-severe disability was present in 45 % at 3 months.</p> <p>Conclusion</p> <p>This prospective community-based study shows one of the lowest incidences of stroke in Europe, as well as one of the lowest case fatality and disability rates at 90 days after stroke.</p

Breast cancer incidence and overdiagnosis in Catalonia (Spain)

Introduction: Early detection of breast cancer (BC) with mammography may cause overdiagnosis and overtreatment, detecting tumors which would remain undiagnosed during a lifetime. The aims of this study were: first, to model invasive BC incidence trends in Catalonia (Spain) taking into account reproductive and screening data; and second, to quantify the extent of BC overdiagnosis. Methods: We modeled the incidence of invasive BC using a Poisson regression model. Explanatory variables were: age at diagnosis and cohort characteristics (completed fertility rate, percentage of women that use mammography at age 50, and year of birth). This model also was used to estimate the background incidence in the absence of screening. We used a probabilistic model to estimate the expected BC incidence if women in the population used mammography as reported in health surveys. The difference between the observed and expected cumulative incidences provided an estimate of overdiagnosis. Results: Incidence of invasive BC increased, especially in cohorts born from 1940 to 1955. The biggest increase was observed in these cohorts between the ages of 50 to 65 years, where the final BC incidence rates more than doubled the initial ones. Dissemination of mammography was significantly associated with BC incidence and overdiagnosis. Our estimates of overdiagnosis ranged from 0.4% to 46.6%, for women born around 1935 and 1950, respectively. Conclusions: Our results support the existence of overdiagnosis in Catalonia attributed to mammography usage, and the limited malignant potential of some tumors may play an important role. Women should be better informed about this risk. Research should be oriented towards personalized screening and risk assessment tools

SORT : statistics and operations research transactions

Títol abreujat: Sort (Barc.)Statistics and Operations Research Transactions, SORT, formerly Qüestiió, is an international journal launched in 2003. It is published twice-yearly, in English, by the Statistical Institute of Catalonia (Idescat). The journal is co-edited by the Universitat Politècnica de Catalunya, Universitat de Barcelona, Universitat Autonòma de Barcelona and Universitat de Girona, with the co-operation of the Spanish Section of the International Biometric Society. SORT promotes the publication of original articles of a methodological or applied nature or motivated by an applied problem in statistics, operations research, official statistics or biometrics as well as book reviews. We encourage authors to include an example of a real data set in their manuscripts.La revista SORT (Statistics and Operations Research Transactions), abans Qüestiió, és una revista internacional llançada el 2003. Es publica dos cops l'any, en anglès, per part de l'Institut d'Estadística de Catalunya (Idescat). La revista està co-editada per la Universitat Politècnica de Catalunya, la Universitat de Barcelona, Universitat Autònoma de Barcelona i la Universitat de Girona, amb la col·laboració de la Secció Espanyola de la International Biometric Society. SORT promou la publicació d'articles originals de caràcter metodològic o relacionat amb l'aplicació de les estadístiques, la investigació d'operacions, les estadístiques oficials o dades biomètriques, així com ressenyes de llibres. Animem als autors a incloure un exemple de dades reals en els seus manuscrits

Els usos de l'aranès a la Val d'Aran segons l'enquesta d'usos lingüístics de l'Idescat

Programa d'Aranèsóc emès per Betevé el 26 de juliol de 2014