Can Routine Data be used to Determine the Target Population of Patients with Type 2 Diabetes in Early Benefit Assessments in Germany?

OBJECTIVES: Since 2011, early benefit assessment of all new drugs launched in Germany is mandatory. The exact determination of the appropriate target population (i. e. patients eligible for a drug) plays an important role for subsequent price negotiations. In type 2 diabetes, the size of the target population varies considerably between company dossiers submitted for assessment. Our aim was to explore whether routine data from all persons insured in German statutory health insurance (SHI) funds can be used to derive information on the size of the target population with type 2 diabetes. METHODS: We explored how the data available at the German Institute of Medical Documentation and Information (DIMDI) can be used to obtain the information required. A data-based concept was chosen and the selection criteria were developed in a multidisciplinary project group. Before finalizing the database query, the criteria were evaluated in a test database and the database query was then repeatedly modified. RESULTS: At the time of the design of our analysis in 2017, the most recent data available at DIMDI were for 2013. The algorithm we developed for identifying patients with type 2 diabetes and classifying them according to their medication, based primarily on the combination of ICD and ATC codes, enabled us to determine the size of target populations for different indications in diabetes mellitus type 2. CONCLUSION: Our methodological approach seems to be suitable to determine target populations in type 2 diabetes.

[Topic Check Medicine: Patient and Consumer Orientation in Topic Collection and Selection for HTA Reports]. / Der ThemenCheck Medizin: Bürgerorientierung bei der Themensammlung und der Themenauswahl für HTA-Berichte.

INTRODUCTION: The involvement of the public in the collection and selection of topics for health technology assessments (HTAs) is an important prerequisite for producing HTA reports on questions actually relevant to patients. In §139b (5) Social Code Book (SGB V), the legislator established the requirements for health insurance members and other interested individuals to propose topics for HTA reports to the Institute for Quality and Efficiency in Health Care (IQWiG). OBJECTIVES: How is the legal remit implemented with regard to the involvement of patients and consumers in topic collection and selection for HTA reports in IQWiG's Topic Check Medicine? TOPIC COLLECTION AND SELECTION: Topic proposals for HTA reports can be submitted by any interested individual via a simple submission form on the "ThemenCheck Medizin" website. If the HTA question is unclear, IQWiG consults the person submitting the proposal. On the basis of topic processing, a Selection Committee comprising members of the public and patient representatives nominates 15 patient-relevant topics suitable for the production of an HTA report. IQWiG then chooses 4-6 topics from which HTA reports are produced. EXPERIENCE WITH TOPIC COLLECTION AND SELECTION: In the first 2 selection cycles (July 2016 to July 2017), 57 topic proposals for HTA reports were submitted from a wide range of topics. At the end of 2016 and 2017, the Selection Committee nominated 15 patient-relevant topics suitable for HTA reports. At the beginning of 2017, IQWiG selected 5, at the beginning of 2018 4 topics for HTA reports. The processing of topics and the selection process were largely judged positively by the Selection Committee. CONCLUSION: A high degree of involvement in topic collection for "ThemenCheck Medizin" is achieved through the simple submission form and the nomination of topics by the Selection Committee. Furthermore, important factors for successful implementation were political support from the legislator, choice of suitable members for the Selection Committee, and support of topic selection by this Committee. How the demand for greater involvement of patients and public can be implemented needs investigation in the future.

Risk of Malignancy in Adenomas Detected During Screening Colonoscopy.

BACKGROUND & AIMS: A higher incidence of proximal interval cancers after colonoscopy has been reported in several follow-up studies. One possible explanation for this might be that proximally located adenomas have greater malignant potential. The aim of the present study was to assess the risk of malignancy in proximal versus distal adenomas in patients included in a large screening colonoscopy database; adenoma shape and the patients' age and sex distribution were also analyzed. METHODS: Data for 2007-2012 from the German National Screening Colonoscopy Registry, including 594,614 adenomas identified during 2,532,298 screening colonoscopies, were analyzed retrospectively. The main outcome measure was the rate of high-grade dysplasia (HGD) in adenomas, used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the rate of HGD found in adenomas were analyzed in relation to patient- and adenoma-related factors using multivariate analysis. RESULTS: HGD histology was noted in 20,873 adenomas (3.5%). Proximal adenoma locations were not associated with a higher HGD rate. The most significant risk factor for HGD was adenoma size (OR 10.36 ≥1 cm vs <1 cm), followed by patient age (OR 1.26 and 1.46 for age groups 65-74 and 75-84 vs 55-64 years) and sex (OR 1.15 male vs female). In comparison with flat adenomas as a reference lesion, sessile lesions had a similar HGD rate (OR 1.02) and pedunculated adenomas had a higher rate (OR 1.23). All associations were statistically significant (P ≤ .05). CONCLUSIONS: In this large screening database, it was found that the rates of adenomas with HGD are similar in the proximal and distal colon. The presence of HGD as a risk marker alone does not explain higher rates of proximal interval colorectal cancer. We suggest that certain lesions (flat, serrated lesions) may be missed in the proximal colon and may acquire a more aggressive biology over time. A combination of endoscopy-related factors and biology may therefore account for higher rates of proximal versus distal interval colorectal cancer.

Expected long-term impact of the German screening colonoscopy programme on colorectal cancer prevention: analyses based on 4,407,971 screening colonoscopies.

AIM: Endoscopy based screening programmes for colorectal cancer (CRC) are being implemented in an increasing number of countries. In Germany, screening colonoscopy at age 55 or older has been offered since the end of 2002. We aimed to estimate the long-term impact of this offer on CRC prevention. METHODS: We estimated numbers of prevented CRC cases by expected age and year of their (prevented) occurrence over four decades (2005-2045) by four state Markov models (non-advanced adenoma, advanced adenoma, preclinical CRC, clinically manifest CRC). Estimates are based on screening colonoscopies reported to the German screening colonoscopy registry in 2003-2012 (N=4,407,971), transition rates between the four states and general population mortality rates. RESULTS: Numbers of prevented clinically manifest CRC cases are projected to increase from <100 in 2005 to approximately 6500 in 2015, 12,600 in 2025, 15,400 in 2035 and 16,000 in 2045, compared to approximately 58,000 incident cases observed in 2003. The annual number of prevented cases is expected to be higher among men than among women and to strongly vary by age. The vast majority of prevented cases would have occurred at age 75 or older. CONCLUSIONS: Despite modest participation rates, the German screening colonoscopy programme will lead to substantial reductions in the CRC burden. The reductions will be fully disclosed in the long run only and predominantly affect numbers of incident cases above 75years of age. Screening offers would need to start at younger ages in order to achieve more effective CRC prevention at younger ages.

Trends in Adenoma Detection Rates During the First 10 Years of the German Screening Colonoscopy Program.

BACKGROUND & AIMS: The adenoma detection rate (ADR) is an important quality indicator of screening colonoscopy; it is inversely associated with risk of interval cancers and colorectal cancer mortality. We assessed trends in the ADR in the first 10 years of the German screening colonoscopy program. METHODS: We calculated age-adjusted and age-specific detection rates of nonadvanced adenomas and advanced adenomas for each calendar year based on 4.4 million screening colonoscopies conducted from 2003 through 2012 and reported to the German screening colonoscopy registry. RESULTS: We observed a steady and strong increase in rate of detection of nonadvanced adenomas in both sexes and all age groups. Age-adjusted rates of detection of nonadvanced adenomas increased from 13.3% to 22.3% among men and from 8.4% to 14.9% among women. This increase was mostly due to an increase in detection rates of adenomas <0.5 cm, and it is partly explained by an innovation effect (higher ADRs among incoming colonoscopists than among leaving colonoscopists, and relatively stable ADRs among continuing colonoscopists). Only modest increases were observed in detection rates of advanced adenomas (from 7.4% to 9.0% among men, and from 4.4% to 5.2% among women) and colorectal cancer. In 2012, overall ADR reached 31.3% and 20.1% in men and women, respectively. CONCLUSIONS: We observed a strong increase in ADRs from 2003 through 2012 in Germany. Although we cannot exclude the effects of secular trends in colorectal neoplasm prevalence, the observed increase was mainly the result of a steady increase in detection of nonadvanced adenomas (especially adenomas <0.5 cm). Further research should address potential implications for defining screening and surveillance intervals.

Prevention, early detection, and overdiagnosis of colorectal cancer within 10 years of screening colonoscopy in Germany.

BACKGROUND & AIMS: Screening colonoscopy was introduced in Germany in October 2002. We aimed to quantify its effects on prevention, early detection, and overdiagnosis of colorectal cancer (CRC) in the 10 years since its introduction. METHODS: We analyzed data from more than 4.4 million screening colonoscopies (conducted on individuals 55-79 years old from 2003 through 2012) available through the national screening colonoscopy registry. CRCs prevented, detected earlier than they would have been without screening, and overdiagnosed (cancers detected at screening colonoscopy that would not have become clinically manifest during the patient's lifetime) were estimated by Markov models. Model parameters included sex-specific and age-specific findings at screening colonoscopy; mortality; rates of transition from nonadvanced to advanced adenoma, advanced adenoma to preclinical cancer, or preclinical cancer to clinically manifest cancer; and protection from screening colonoscopy. RESULTS: Overall, approximately 180,000 CRCs (1/28 screening colonoscopies) were estimated to have been prevented, and more than 40,000 CRCs (1/121 screening colonoscopies) were detected earlier than they would have been without screening, compared with approximately 4500 overdiagnoses (1/1089 screening colonoscopies). Almost all CRCs prevented or detected earlier than they would have been without screening resulted from screening colonoscopies performed on individuals up to 75 years old (97% and 89%, respectively), whereas 28% of overdiagnoses occurred from screening colonoscopies of individuals older than 75 years old. CONCLUSIONS: On the basis of a 10-year analysis of data from a national registry in Germany, screening colonoscopies have large potential for prevention and early detection of CRC, with low risk of overdiagnosis.

Incidence of colorectal adenomas: birth cohort analysis among 4.3 million participants of screening colonoscopy.

BACKGROUND: Most colorectal cancers develop from adenomas. We aimed to estimate sex- and age-specific incidence rates of colorectal adenomas and to assess their potential implications for colorectal cancer screening strategies. METHODS: Sex- and age-specific incidence rates of colorectal adenomas were derived by a birth cohort analysis using data from 4,322,085 screening colonoscopies conducted in Germany and recorded in a national database in 2003-2012. In addition, cumulative risks of colorectal cancer among colonoscopically neoplasm-free men and women were estimated by combining adenoma incidence rates with previously derived adenoma-colorectal cancer transition rates. RESULTS: Estimated annual incidence in percentage (95% confidence interval) in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 was 2.4 (2.2-2.6), 2.3 (2.1-2.6), 2.4 (2.1-2.6), 2.2 (1.8-2.5), and 1.8 (1.2-2.3) among men, and 1.4 (1.3-1.5), 1.5 (1.4-1.7), 1.6 (1.4-1.8), 1.6 (1.3-1.8), and 1.2 (0.8-1.6) among women. Estimated 10- and 15-year risks of clinically manifest colorectal cancer were 0.1% and 0.5% or lower, respectively, in all groups assessed. CONCLUSIONS: Annual incidence rates of colorectal adenomas are below 2.5% and 2% among men and women, respectively, and show little variation by age. IMPACT: Risk of clinically manifest colorectal cancer is expected to be very small within 10 years and beyond after negative colonoscopy for men and women at all ages. The use of rescreening after a negative screening colonoscopy above 60 years of age may be very limited.

Data quality of the German screening colonoscopy registry.

BACKGROUND AND STUDY AIMS: The German screening colonoscopy program is accompanied by a central registry that records the main outcome quality indicators, namely colonoscopy completion rate, adenoma detection rate (ADR), and complication rate. The aim of the present study was to assess the quality of these registry data by comparing them with data from a prospective quality assurance study based on a self-reporting audit and patient feedback of screening colonoscopy. PATIENTS AND METHODS: The completeness of registry information was analyzed by comparing it with prospective data gathered by audit and patient feedback in a previous quality assurance study (ClinicalTrials.gov registration number: NCT00860665) between October 2006 and March 2008. The main outcome parameters were colonoscopy completion rate, ADR, and complication rate. Complications were recorded in three steps in the audit study using case report forms (immediate and subsequent documentation by physicians [CRF-1 and CRF-2], and patient follow-up [CRF-3]), but were documented in the registry without differentiation. RESULTS: A total of 12 134 individuals (mean age 64.5 years; 47 % men) who underwent screening colonoscopy at 19 private practices in Berlin over the 18-month period were included in the audit study. Patient feedback was obtained for 90.1 %. A total of 12 150 cases had been recorded in the registry by the same private practices during the same period. Colonoscopy completion rate and ADR data were comparable in the audit study and registry (completion rate 98.2 % vs. 97.7 %; ADR 21.0 % vs. 20.5 %). However, compared with the registry data, the complication rate was 3.1-fold higher in the audit (0.46 % vs. 0.15 %; P < 0.001), and double (0.33 % vs. 0.15 %; P < 0.05) when patient feedback was not included. CONCLUSIONS: Of the screening colonoscopy quality parameters, colonoscopy completion rate and ADR, but not complication rates, were reliably documented in the German national screening colonoscopy registry. Data on complications need to be appropriately standardized and audited in order to be used for credentialing and benchmarking purposes.

Natural history of colorectal adenomas: birth cohort analysis among 3.6 million participants of screening colonoscopy.

BACKGROUND: Most colorectal cancers (CRC) develop from adenomas. Knowledge of the natural history of colorectal adenomas, which is not directly observable for ethical reasons, is crucial for designing cost-effective CRC screening strategies. METHODS: We derived transition rates from carriage of nonadvanced adenoma to carriage of advanced adenoma to carriage of CRC by sex and age in birth cohort analyses among 3,593,420 participants in the German screening colonoscopy program in 2003-2010. RESULTS: Transition rates from advanced adenoma to CRC carriage were similar in men and women, but monotonically and significantly increased with age. Estimated annual transition percentages [(95% confidence interval (CI)] in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 years were 2.6 (2.4-2.9), 3.1 (2.8-3.3), 3.8 (3.5-4.1), 5.1 (4.8-5.5), and 5.2 (4.6-5.8) among men, and 2.5 (2.2-2.7), 2.7 (2.4-3.0), 3.8 (3.5-4.1), 5.0 (4.5-5.4), and 5.6 (4.9-6.3) among women. Estimated annual transitions from carriage of nonadvanced to carriage of advanced adenoma were in a narrow range from 3.6% to 4.7% for all age and sex groups. CONCLUSIONS: Despite low annual transition rates, cumulative transition rates from advanced adenoma to CRC carriage are expected to exceed by 60%, 50%, and 40% for age intervals 55-80, 65-80, and 70-80 years, respectively, in both sexes. Cumulative transition rates from nonadvanced adenoma to CRC carriage are expected to be close to 30% for age interval 55-80 years, but less than 2% for age interval 75-80 years. IMPACT: Our results enhance the empirical basis for modeling CRC screening strategies.

Factors determining the quality of screening colonoscopy: a prospective study on adenoma detection rates, from 12,134 examinations (Berlin colonoscopy project 3, BECOP-3).

BACKGROUND: Screening colonoscopy (SC) outcome quality is best determined by the adenoma detection rate (ADR). The substantial variability in the ADRs between endoscopists may reflect different skills, experience and/or equipment. OBJECTIVE: To analyse the potential factors that may influence ADR variance, including case volume. DESIGN: 12,134 consecutive SCs (mean age 64.5 years, 47% men) from 21 Berlin private-practice colonoscopists were prospectively studied during 18 months. The data were analysed using a two-level mixed linear model to adequately address the characteristics of patients and colonoscopists. The ADR was regressed after considering the following factors: sex, age, bowel cleanliness, NSAID intake, annual SC case volume, lifetime experience, instrument withdrawal times, instrument generations used, and the number of annual continuing medical education (CME) meetings attended by the physician. The case volume was also retrospectively analysed from the 2007 national SC registry data (312,903 colonoscopies and 1004 colonoscopists). RESULTS: The patient factors that correlated with the ADR were sex, age (p<0.001) and low quality of bowel preparation (p=0.005). The factors that were related to the colonoscopists were the number of CME meetings attended (p=0.012) and instrument generation (p=0.001); these factors accounted for approximately 40% of the interphysician variability. Within a narrow range (6-11 min), the withdrawal time was not correlated with the ADR. Annual screening case volume did not correlate with the ADR, and this finding was confirmed by the German registry data. CONCLUSIONS: The outcome quality of screening colonoscopies is mainly influenced by individual colonoscopist factors (ie, CME activities) and instrument quality. CLINICAL TRIAL REGISTRATION NUMBER: Clinical Trial Gov Registration number: NCT00860665.

Matching of controls may lead to biased estimates of specificity in the evaluation of cancer screening tests.

OBJECTIVES: In the evaluation of cancer screening tests, cancer-free controls are often matched to cancer cases on factors such as sex and age. We assessed the potential merits and pitfalls of such matching using an example from colorectal cancer (CRC) screening. STUDY DESIGN AND SETTING: We compared sex and age distribution of CRC cases and cancer-free people undergoing screening colonoscopy in Germany in 2006 and 2007. We assessed specificity by sex and age of two immunochemical fecal occult blood tests (iFOBTs) in a study among screening colonoscopy participants conducted in the same years, and we assessed the expected impact of matching by sex and age on the validity of specificity estimates at various cut points. RESULTS: In the screening colonoscopy program, the proportion of men and mean age were 59.6% and 68.6 years among 10,324 CRC patients compared with 45.6% and 64.7 years, respectively, among 997,490 cancer-free participants. The specificity of the iFOBTs was higher among women than among men and decreased with age. Matching of cancer-free controls by age and sex would have led to the underestimation of specificity at all cut points assessed. CONCLUSION: In the evaluation of cancer screening tests, matching of controls may lead to biased estimates of specificity.

Capsule colonoscopy increases uptake of colorectal cancer screening.

BACKGROUND: Screening colonoscopy effectiveness is hampered by limited adherence by the general population. The present prospective study was performed to evaluate whether adding capsule colonoscopy to the endoscopic screening options increases uptake. METHODS: Invitation letters were sent to 2150 persons above the age of 55 insured with a German medical insurance company in the area of Rinteln, Lower Saxony with a baseline spontaneous annual screening colonoscopy uptake of 1 %. Both capsule or conventional colonoscopy were offered. Interested persons were given information about the two screening options by four local gastroenterologists and examinations were then performed according to screenees' final choice. RESULTS: 154 persons sought further information, and 34 and 90 underwent conventional and capsule colonoscopy, respectively. Colonoscopy uptake was thus increased by the invitation process by 60 % (1.6 % vs. 1 %; p = 0.075), while the option of capsule endoscopy led to a fourfold increase of screening uptake (4.2 % vs. 1 %, p < 0.001). Despite similar age distribution in both sex groups, uptake in men was significantly higher (5.6 % vs. 2.8 %, p = 002). However, overall adenoma yield was not different in both groups. CONCLUSIONS: The present study suggests that offering the option of capsule colonoscopy increases uptake of endoscopic colorectal cancer screening. However, capsule endoscopy sensitivity for adenoma detection needs to be improved.

Efficacy of a nationwide screening colonoscopy program for colorectal cancer.

BACKGROUND & AIMS: Screening colonoscopy examinations for colorectal cancer are offered in the United States and some European countries. Data on results and adverse effects of screening colonoscopy are limited. In autumn 2002, colonoscopy was introduced as part of a nationwide cancer screening program in Germany; it was offered to the general population for individuals 55 years of age or older. We collected and analyzed data from this program. METHODS: We performed a prospective cross-sectional study, collecting results from 2,821,392 screening colonoscopies performed at more than 2100 practices by highly qualified endoscopists in Germany from January 2003 to December 2008. Data on participation, colorectal adenoma and cancer detection, and complications were collected using standardized documentation forms. The data generated were centrally processed and evaluated. RESULTS: The cumulative participation rate was 17.2% of eligible women and 15.5% of eligible men 55-74 years old. The adenoma detection rate (ADR) was 19.4%, with a higher rate in men (25.8% vs 16.7% in women). Advanced adenomas were found in 6.4% of patients. Carcinomas were detected in 25,893 subjects (0.9%); most were of an early UICC stage (I, 47.3%; II, 22.3%; III, 20.7%; IV, 9.6%). The ADRs for gastroenterologists and nongastroenterologists were 25.1% and 22.3%, respectively (adjusted odds ratio, 1.18; 95% confidence interval, 1.16-1.21). The overall complication rate was 2.8/1000 colonoscopies, and the rate of serious complications was 0.58/1000 colonoscopies. CONCLUSIONS: A nationwide colonoscopy screening program that uses highly qualified endoscopists can detect a significant number of adenomas and early-stage carcinomas. The ADR for gastroenterologists was higher than for nongastroenterologists.

General ultrasound screening reduces the rate of first operative procedures for developmental dysplasia of the hip: a case-control study.

OBJECTIVES: To assess the effectiveness of general ultrasound screening to prevent first operative procedures of the hip. STUDY DESIGN: We conducted a case-control study in a population in which general ultrasound screening supplementing clinical screening is recommended and offered free of charge for all children. Participation in ultrasound screening before week 7 as recommended in Germany was the exposure of interest. Case ascertainment was based on active surveillance in orthopedic hospitals. The case definition was: first operative procedure for developmental dysplasia of the hip (closed reduction, open reduction, or osteotomy) in children >9 weeks old and <5 years old and born between 1996 and 2001. Control subjects from the same birth cohorts were recruited in telephone surveys. RESULTS: Cases of first operative procedures for developmental dysplasia of the hip (n = 446) were compared with 1173 control subjects for ultrasound screening. Effectiveness of ultrasound screening to prevent first operative procedures for developmental dysplasia of the hip was estimated as 52% (95% CI, 32-67). Effectiveness did not vary substantially for closed and open reductions and osteotomy. CONCLUSIONS: General ultrasound screening reduces the rate of operative procedures for developmental dysplasia of the hip; the impact on developmental dysplasia of the hip. Treatment rates and avascular necrosis need further assessment to balance the benefit against potential overtreatment and adverse effects.

Sojourn time of preclinical colorectal cancer by sex and age: estimates from the German national screening colonoscopy database.

The sojourn time of preclinical colorectal cancer is a critical parameter in modeling effectiveness and cost-effectiveness of colorectal cancer screening. For ethical reasons, it cannot be observed directly, and available estimates are based mostly on relatively small historic data sets that do not include differentiation by age and sex. The authors derived sex- and age-specific estimates (age groups: 55-59, 60-64, 65-69, 70-74, 75-79, and ≥80 years) of mean sojourn time, combining data from the German national screening colonoscopy registry (based on 1.88 million records) and data from population-based cancer registries (population base: 37.9 million people) for the years 2003-2006. Estimates of mean sojourn time were similar for both sexes and all age groups and ranged from 4.5 years (95% confidence interval: 4.1, 4.8) to 5.8 years (95% confidence interval: 5.3, 6.3) for the subgroups assessed. Sensitivity analyses indicated that mean sojourn time might be approximately 1.5 years longer if colorectal cancer prevalence in nonparticipants of screening colonoscopy is 20% lower than prevalence in participants or 1 year shorter if it exceeds the prevalence in participants by 20%. This study provides, for the first time, precise estimates of sojourn time by age and sex, and it suggests that sojourn times are remarkably consistent across age groups and in both sexes.

Eight years of colonoscopic bowel cancer screening in Germany: initial findings and projections.

BACKGROUND: Screening colonoscopy has been offered in Germany since the end of 2002. Our aim was to estimate numbers of colorectal cancers prevented or detected early by screening colonoscopy in 2003-2010. METHODS: Participation rates and prevalences of advanced adenomas and colorectal cancers at screening colonoscopy in 2003-2008 were obtained from the national screening colonoscopy database by age, sex and calendar year. For 2009 and 2010, levels were assumed to remain at those observed in 2008. These data were combined in Markov models with population figures and estimates of transition rates from advanced adenomas to preclinical colorectal cancer and from preclinical cancer to clinically manifest cancer, accounting for total mortality. RESULTS: An estimated total number of 98 734 cases of colorectal cancer at ages 55-84 years are expected to have been prevented in Germany by removal of advanced adenomas by the end of 2010. These cancers might have become clinically manifest a median time period of 10 years after screening colonoscopy. Another 47 168 cases are expected to have been detected early at screening colonoscopy, often in a curable stage. CONCLUSION: Despite limited participation, the German screening colonoscopy program makes a major contribution to prevention and early detection of colorectal cancer.

Estimated long-term effects of the initial 6 years of the German screening colonoscopy program.

BACKGROUND: Colorectal cancer is the most common cancer in Germany. Screening colonoscopies have been offered as a primary screening tool in Germany since the end of 2002. OBJECTIVE: To estimate the numbers of clinically manifest colorectal cancers prevented by detection and removal of advanced adenomas in the initial 6 years of the program. DESIGN: Markov model with single-year transitions. SETTING: German screening colonoscopy program. PATIENTS: Participants in the screening colonoscopy program from 2003 to 2008. INTERVENTIONS: Screening colonoscopy with the removal of advanced colorectal neoplasms. MAIN OUTCOME MEASUREMENTS: The expected numbers of incident colorectal cancers prevented by detection and removal of advanced adenomas. RESULTS: An estimated total number of 73,024 cases of colorectal cancer might have developed from the removed advanced adenomas and become clinically manifest between 55 and 84 years of age in the absence of screening colonoscopy. This number exceeds the number of colorectal cancers diagnosed in 2002 by 27%. Among prevented cancers, 8%, 43%, and 49% would have occurred at ages 55 to 64, 65 to 74, and 75 to 84 years (median age 74 years), respectively; 60% and 40% would have occurred among men and women, respectively; and 22%, 32%, 25%, and 20% would have occurred within 1 to 5, 6 to 10, 11 to 15, and 16 to 30 years, respectively, after colonoscopy (median 10 years). LIMITATIONS: Diagnoses of advanced adenomas are based on records from a large number of endoscopists and pathology laboratories. CONCLUSIONS: Despite relatively low screening participation, the German screening colonoscopy program is expected to make a major contribution to the prevention of colorectal cancer, even though most of the impact will only be seen in the longer run.

Sex, age, and birth cohort effects in colorectal neoplasms: a cohort analysis.

BACKGROUND: Prevalence of advanced colorectal neoplasms increases with age and is higher among men than women. Cross-sectional analyses estimated that men reach an equivalent prevalence at a much younger age than women. However, cross-sectional estimates may be confounded by birth cohort effects. OBJECTIVE: To estimate age and cohort effects in advanced colorectal neoplasms and to adjust risk-advancement periods for men compared with women for birth cohort effects. DESIGN: Age-cohort analyses. SETTING: German screening colonoscopy program, 2003 to 2007. PARTICIPANTS: 2 185 153 participants aged 55 to 75 years. MEASUREMENTS: Sex- and age-specific prevalence of colorectal cancer (CRC) and advanced neoplasms (CRC or advanced adenoma) were plotted with and without stratification by birth cohort. Risk-advancement periods with 95% CI for men compared with women were estimated from log-binomial regression models with and without cross-sectional analysis adjustment for birth cohort effects. RESULTS: Overall, 17 196 participants (0.8%) had CRC and 152 429 (7.0%) had any advanced neoplasm. Age-specific prevalence was higher in men than in women and in later birth cohorts. The apparent modest increase in prevalence by age in cross-sectional analysis was much steeper after birth cohort effects were controlled for. In cross-sectional analysis, risk-advancement periods (95% CI) for men compared with women were 8.4 years (CI, 7.7 to 9.0 years) and 16.1 years (CI, 15.8 to 16.5 years) for CRC and any advanced neoplasm, respectively, and 3.4 years (CI, 2.6 to 4.3 years) and 6.9 years (CI, 6.4 to 7.4 years) after controlling for birth cohort effects. LIMITATION: Information on covariates that could explain cohort effects was lacking. CONCLUSION: In this population, strong cohort effects reduced age gradients in advanced colorectal neoplasms and inflated risk-advancement periods for men compared with women, but major risk advancement persisted, even after birth cohort effects were controlled for. PRIMARY FUNDING SOURCE: None.

Protection from right- and left-sided colorectal neoplasms after colonoscopy: population-based study.

BACKGROUND: Colonoscopy is used for early detection and prevention of colorectal cancer, but evidence on the magnitude of overall protection and protection according to anatomical site through colonoscopy performed in the community setting is sparse. We assessed whether receiving a colonoscopy in the preceding 10-year period, compared with no colonoscopy, was associated with prevalence of advanced colorectal neoplasms (defined as cancers or advanced adenomas) at various anatomical sites. METHODS: A statewide cross-sectional study was conducted among 3287 participants in screening colonoscopy between May 1, 2005, and December 31, 2007, from the state of Saarland in Germany who were aged 55 years or older. Prevalence of advanced colorectal neoplasms was ascertained by screening colonoscopy and histopathologic examination of any polyps excised. Previous colonoscopy history was obtained by standardized questionnaire, and its association with prevalence of advanced colorectal neoplasms was estimated, after adjustment for potential confounding factors by log-binomial regression. RESULTS: Advanced colorectal neoplasms were detected in 308 (11.4%) of the 2701 participants with no previous colonoscopy compared with 36 (6.1%) of the 586 participants who had undergone colonoscopy within the preceding 10 years. After adjustment, overall and site-specific adjusted prevalence ratios for previous colonoscopy in the previous 10-year period were as follows: overall, 0.52 (95% confidence interval [CI] = 0.37 to 0.73); cecum and ascending colon, 0.99 (95% CI = 0.50 to 1.97); hepatic flexure and transverse colon, 1.21 (95% CI = 0.60 to 2.42); right-sided colon combined (cecum to transverse colon), 1.05 (95% CI = 0.63 to 1.76); splenic flexure and descending colon, 0.36 (95% CI = 0.16 to 0.82); sigmoid colon, 0.29 (95% CI = 0.16 to 0.53); rectum, 0.07 (95% CI = 0.02 to 0.40); left colon and rectum combined (splenic flexure to rectum, referred to as left-sided elsewhere), 0.33 (95% CI = 0.21 to 0.53). CONCLUSION: Prevalence of left-sided advanced colorectal neoplasms, but not right-sided advanced neoplasms, was strongly reduced within a 10-year period after colonoscopy, even in the community setting.