Incidence and Risk Factors for Hepatocellular Carcinoma in Cirrhosis: The Multicenter Hepatocellular Carcinoma Early Detection Strategy (HEDS) Study

BACKGROUND & AIMS

Worldwide, hepatocellular carcinoma (HCC) is a common malignancy. We aimed to prospectively determine the incidence and risk factors of HCC in a U.S.

COHORT

METHODS

The multicenter Hepatocellular Carcinoma Early Detection Strategy study of the National Institutes of Health prospectively enrolled patients with cirrhosis who underwent standard surveillance for HCC. Demographics, medical and family history, etiology of liver disease, and clinical features were evaluated for associations with HCC.

RESULTS

Between April 10, 2013 and December 31, 2021, 1723 patients were enrolled and confirmed eligible. During median follow-up of 2.2 years (range, 0-8.7 years), there were 109 incident cases of HCC for an incidence rate of 2.4 per 100 person-years: 88 (81%) patients with very early/early Barcelona Clinic Liver Cancer stage (0, A), 20 (18%) intermediate stage (B), and 1 (1%) unknown stage. Risk factor analyses were restricted to 1325 patients, including 95 incident HCC, with at least 6 months of follow-up. The majority were men (53.2%), obese or severely obese (median body mass index, 30.2 kg/m2), and white (86.3%); 42.0% had history of hepatitis C virus infection, 20.7% had alcoholic liver disease, and 24.9% had nonalcoholic fatty liver disease. Fourteen risk factors for HCC were significant (P < .05) in univariate analyses, and a multivariate subset was selected using stepwise logistic regression. The multivariate subset contained gender (P < .001; male; odds ratio [OR], 2.47; 95% confidence interval [CI], 1.54-4.07), years with cirrhosis (P = .004; OR, 1.06; 95% CI, 1.02-1.1), family history of liver cancer (P = .02; yes; OR, 2.69; 95% CI, 1.11-5.86), age (per 5 years; P = .02; OR, 1.17; 95% CI, 1.03-1.33), obesity (P = .02; yes; OR, 1.7; 95% CI, 1.08-2.73), aspartate aminotransferase (log(1+AST); P = .06; OR, 1.54; 95% CI, 0.97-2.42), alpha-fetoprotein (log(1+AFP); P = .07; OR, 1.32; 95% CI, 0.97-1.77), and albumin (P = .10; OR, 0.7; 95% CI, 0.46-1.07).

CONCLUSIONS

Thus far, this is the largest prospective and geographically diverse study of a U.S. cohort of patients with cirrhosis that validates known risk factors for HCC (gender, age, obesity, years with cirrhosis, family history of liver cancer, baseline AFP, albumin, and AST). The incidence of HCC was 2.4% per 100 person-years.

Evaluating Screening Participation, Follow-up, and Outcomes for Breast, Cervical, and Colorectal Cancer in the PROSPR Consortium

BACKGROUND

Cancer screening is a complex process encompassing risk assessment, the initial screening examination, diagnostic evaluation, and treatment of cancer precursors or early cancers. Metrics that enable comparisons across different screening targets are needed. We present population-based screening metrics for breast, cervical, and colorectal cancers for nine sites participating in the Population-based Research Optimizing Screening through Personalized Regimens consortium.

METHODS

We describe how selected metrics map to a trans-organ conceptual model of the screening process. For each cancer type, we calculated calendar year 2013 metrics for the screen-eligible target population (breast: ages 40-74 years; cervical: ages 21-64 years; colorectal: ages 50-75 years). Metrics for screening participation, timely diagnostic evaluation, and diagnosed cancers in the screened and total populations are presented for the total eligible population and stratified by age group and cancer type.

RESULTS

The overall screening-eligible populations in 2013 were 305 568 participants for breast, 3 160 128 for cervical, and 2 363 922 for colorectal cancer screening. Being up-to-date for testing was common for all three cancer types: breast (63.5%), cervical (84.6%), and colorectal (77.5%). The percentage of abnormal screens ranged from 10.7% for breast, 4.4% for cervical, and 4.5% for colorectal cancer screening. Abnormal breast screens were followed up diagnostically in almost all (96.8%) cases, and cervical and colorectal were similar (76.2% and 76.3%, respectively). Cancer rates per 1000 screens were 5.66, 0.17, and 1.46 for breast, cervical, and colorectal cancer, respectively.

CONCLUSIONS

Comprehensive assessment of metrics by the Population-based Research Optimizing Screening through Personalized Regimens consortium enabled systematic identification of screening process steps in need of improvement. We encourage widespread use of common metrics to allow interventions to be tested across cancer types and health-care settings.

Receipt of Colonoscopy Following Diagnosis of Advanced Adenomas: An Analysis within Integrated Healthcare Delivery Systems

BACKGROUND

To reduce colorectal cancer incidence and mortality, experts recommend surveillance colonoscopy 3 years after advanced adenoma removal. Little is known about adherence to that interval.

METHODS

We describe patterns of and factors associated with subsequent colonoscopy among persons with ≥3 adenomas and/or ≥1 adenoma with villous/tubulovillous histology in four U.S. integrated healthcare delivery systems. We report Kaplan-Meier estimators of the cumulative percentage of patients undergoing colonoscopy 6 months to 3.5 years after an index colonoscopy with high-risk findings. Combining data from three healthcare systems, we used multivariable logistic regression with inverse probability of censoring weights to estimate ORs and 95% confidence intervals (CI) for associations between patient characteristics and receipt of subsequent colonoscopy.

RESULTS

Among 6,909 persons with advanced adenomas, the percent receiving a subsequent colonoscopy 6 months to 3.5 years later ranged from 18.3% (95% CI: 11.7%-27.8%) to 59.5% (95% CI: 53.8%-65.2%) across healthcare systems. Differences remained significant in the multivariable model. Patients with ≥3 adenomas were more likely than those with 1 to 2 villous/tubulovillous adenomas to undergo subsequent colonoscopy. Subsequent colonoscopy was also more common for patients ages 60-74 and less common for patients ages 80 to 89 compared with those ages 50 to 54 years at their index colonoscopy. Sex, race/ethnicity, and comorbidity index score were generally not associated with subsequent colonoscopy receipt.

CONCLUSIONS

Colonoscopy within the recommended interval following advanced adenoma was underutilized and varied by healthcare system, age, and number of adenomas.

IMPACT

Strategies to improve adherence to surveillance colonoscopy following advanced adenomas are needed.

Multilevel Intervention Raises Latina Participation in Mammography Screening: Findings from ¡Fortaleza Latina!

BACKGROUND

Breast cancer is the most commonly diagnosed cancer in women in the United States, and Latinas have relatively low rates of screening participation. The Multilevel Intervention to Increase Latina Participation in Mammography Screening study (¡Fortaleza Latina!) sought to assess the efficacy of a clinic- and patient-level program to increase breast cancer screening among Latinas in Western Washington who seek care at a safety net health center.

METHODS

The study enrolled 536 Latinas ages 42 to 74 who had a primary care clinic visit in the previous 5 years and had not obtained a mammogram in the previous 2 years. Participants were block-randomized within clinic to either (i) a control arm (usual care) or (ii) a promotora-led, motivational interviewing intervention that included a home visit and telephone follow-up. At the clinic level, two of four participating clinics were provided additional mammography services delivered by a mobile mammography unit.

RESULTS

Rates of screening mammography 1 year post-randomization were 19.6% in the intervention group and 11.0% in the usual care group (P < 0.01), based on medical record data. No significant differences in participants' mammography screening were observed in clinics randomized to additional mammography services versus usual care (15.8% vs. 14.4%; P = 0.68).

CONCLUSION

This multilevel intervention of promotora-delivered motivational interviewing and free mammography services modestly raised rates of participation in breast cancer screening among Latinas.

IMPACT

Our findings can inform future efforts to boost mammography participation in safety net practices. Cancer Epidemiol Biomarkers Prev; 25(4); 584-92. ©2016 AACR SEE ALL ARTICLES IN THIS CEBP FOCUS SECTION, "MULTILEVEL APPROACHES TO ADDRESSING CANCER HEALTH DISPARITIES".

Association Between Primary Care Visits and Colorectal Cancer Screening Outcomes in the Era of Population Health Outreach

BACKGROUND

Population outreach strategies are increasingly used to improve colorectal cancer (CRC) screening. The influence of primary care on cancer screening in this context is unknown.

OBJECTIVE

To assess associations between primary care provider (PCP) visits and receipt of CRC screening and colonoscopy after a positive fecal immunochemical (FIT) or fecal occult blood test (FOBT).

DESIGN

Population-based cohort study.

PARTICIPANTS

A total of 968,072 patients ages 50-74 years who were not up to date with CRC screening in 2011 in four integrated healthcare systems (three with screening outreach programs using FIT kits) in the Population-Based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium.

MEASURES

Demographic, clinical, PCP visit, and CRC screening data were obtained from electronic health records and administrative databases. We examined associations between PCP visits in 2011 and receipt of FIT/FOBT, screening colonoscopy, or flexible sigmoidoscopy (CRC screening) in 2012 and follow-up colonoscopy within 3 months of a positive FIT/FOBT in 2012. We used multivariable logistic regression and propensity score models to adjust for confounding.

RESULTS

Fifty-eight percent of eligible patients completed a CRC screening test in 2012, most by FIT. Those with a greater number of PCP visits had higher rates of CRC screening at all sites. Patients with ≥1 PCP visit had nearly twice the adjusted-odds of CRC screening (OR = 1.88, 95 % CI: 1.86-1.89). Overall, 79.6 % of patients with a positive FIT/FOBT completed colonoscopy within 3 months. Patients with ≥1 PCP visit had 30 % higher adjusted odds of completing colonoscopy after positive FIT/FOBT (OR = 1.30; 95 % CI: 1.22-1.40).

CONCLUSIONS

Patients with a greater number of PCP visits had higher rates of both incident CRC screening and colonoscopy after positive FIT/FOBT, even in health systems with active population health outreach programs. In this era of virtual care and population outreach, primary care visits remain an important mechanism for engaging patients in cancer screening.

Follow-Up of Abnormal Breast and Colorectal Cancer Screening by Race/Ethnicity

INTRODUCTION

Timely follow-up of abnormal tests is critical to the effectiveness of cancer screening, but may vary by screening test, healthcare system, and sociodemographic group.

METHODS

Timely follow-up of abnormal mammogram and fecal occult blood testing or fecal immunochemical tests (FOBT/FIT) were compared by race/ethnicity using Population-Based Research Optimizing Screening through Personalized Regimens consortium data. Participants were women with an abnormal mammogram (aged 40-75 years) or FOBT/FIT (aged 50-75 years) in 2010-2012. Analyses were performed in 2015. Timely follow-up was defined as colonoscopy ≤3 months following positive FOBT/FIT; additional imaging or biopsy ≤3 months following Breast Imaging Reporting and Data System Category 0, 4, or 5 mammograms; or ≤9 months following Category 3 mammograms. Logistic regression was used to model receipt of timely follow-up adjusting for study site, age, year, insurance, and income.

RESULTS

Among 166,602 mammograms, 10.7% were abnormal; among 566,781 FOBT/FITs, 4.3% were abnormal. Nearly 96% of patients with abnormal mammograms received timely follow-up versus 68% with abnormal FOBT/FIT. There was greater variability in receipt of follow-up across healthcare systems for positive FOBT/FIT than for abnormal mammograms. For mammography, black women were less likely than whites to receive timely follow-up (91.8% vs 96.0%, OR=0.71, 95% CI=0.51, 0.97). For FOBT/FIT, Hispanics were more likely than whites to receive timely follow-up than whites (70.0% vs 67.6%, OR=1.12, 95% CI=1.04, 1.21).

CONCLUSIONS

Timely follow-up among women was more likely for abnormal mammograms than FOBT/FITs, with small variations in follow-up rates by race/ethnicity and larger variation across healthcare systems.

Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents

BACKGROUND

Overweight and obesity are increasing worldwide. To help assess their relevance to mortality in different populations we conducted individual-participant data meta-analyses of prospective studies of body-mass index (BMI), limiting confounding and reverse causality by restricting analyses to never-smokers and excluding pre-existing disease and the first 5 years of follow-up.

METHODS

Of 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America from 239 prospective studies (median follow-up 13·7 years, IQR 11·4-14·7), 3 951 455 people in 189 studies were never-smokers without chronic diseases at recruitment who survived 5 years, of whom 385 879 died. The primary analyses are of these deaths, and study, age, and sex adjusted hazard ratios (HRs), relative to BMI 22·5-<25·0 kg/m(2).

FINDINGS

All-cause mortality was minimal at 20·0-25·0 kg/m(2) (HR 1·00, 95% CI 0·98-1·02 for BMI 20·0-<22·5 kg/m(2); 1·00, 0·99-1·01 for BMI 22·5-<25·0 kg/m(2)), and increased significantly both just below this range (1·13, 1·09-1·17 for BMI 18·5-<20·0 kg/m(2); 1·51, 1·43-1·59 for BMI 15·0-<18·5) and throughout the overweight range (1·07, 1·07-1·08 for BMI 25·0-<27·5 kg/m(2); 1·20, 1·18-1·22 for BMI 27·5-<30·0 kg/m(2)). The HR for obesity grade 1 (BMI 30·0-<35·0 kg/m(2)) was 1·45, 95% CI 1·41-1·48; the HR for obesity grade 2 (35·0-<40·0 kg/m(2)) was 1·94, 1·87-2·01; and the HR for obesity grade 3 (40·0-<60·0 kg/m(2)) was 2·76, 2·60-2·92. For BMI over 25·0 kg/m(2), mortality increased approximately log-linearly with BMI; the HR per 5 kg/m(2) units higher BMI was 1·39 (1·34-1·43) in Europe, 1·29 (1·26-1·32) in North America, 1·39 (1·34-1·44) in east Asia, and 1·31 (1·27-1·35) in Australia and New Zealand. This HR per 5 kg/m(2) units higher BMI (for BMI over 25 kg/m(2)) was greater in younger than older people (1·52, 95% CI 1·47-1·56, for BMI measured at 35-49 years vs 1·21, 1·17-1·25, for BMI measured at 70-89 years; pheterogeneity<0·0001), greater in men than women (1·51, 1·46-1·56, vs 1·30, 1·26-1·33; pheterogeneity<0·0001), but similar in studies with self-reported and measured BMI.

INTERPRETATION

The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in four continents. This finding supports strategies to combat the entire spectrum of excess adiposity in many populations.

FUNDING

UK Medical Research Council, British Heart Foundation, National Institute for Health Research, US National Institutes of Health.

Association between body mass index and cardiovascular disease mortality in east Asians and south Asians: pooled analysis of prospective data from the Asia Cohort Consortium

OBJECTIVE

To evaluate the association between body mass index and mortality from overall cardiovascular disease and specific subtypes of cardiovascular disease in east and south Asians.

DESIGN

Pooled analyses of 20 prospective cohorts in Asia, including data from 835,082 east Asians and 289,815 south Asians. Cohorts were identified through a systematic search of the literature in early 2008, followed by a survey that was sent to each cohort to assess data availability.

SETTING

General populations in east Asia (China, Taiwan, Singapore, Japan, and Korea) and south Asia (India and Bangladesh).

PARTICIPANTS

1,124,897 men and women (mean age 53.4 years at baseline).

MAIN OUTCOME MEASURES

Risk of death from overall cardiovascular disease, coronary heart disease, stroke, and (in east Asians only) stroke subtypes.

RESULTS

49,184 cardiovascular deaths (40,791 in east Asians and 8393 in south Asians) were identified during a mean follow-up of 9.7 years. East Asians with a body mass index of 25 or above had a raised risk of death from overall cardiovascular disease, compared with the reference range of body mass index (values 22.5-24.9; hazard ratio 1.09 (95% confidence interval 1.03 to 1.15), 1.27 (1.20 to 1.35), 1.59 (1.43 to 1.76), 1.74 (1.47 to 2.06), and 1.97 (1.44 to 2.71) for body mass index ranges 25.0-27.4, 27.5-29.9, 30.0-32.4, 32.5-34.9, and 35.0-50.0, respectively). This association was similar for risk of death from coronary heart disease and ischaemic stroke; for haemorrhagic stroke, the risk of death was higher at body mass index values of 27.5 and above. Elevated risk of death from cardiovascular disease was also observed at lower categories of body mass index (hazard ratio 1.19 (95% confidence interval 1.02 to 1.39) and 2.16 (1.37 to 3.40) for body mass index ranges 15.0-17.4 and <15.0, respectively), compared with the reference range. In south Asians, the association between body mass index and mortality from cardiovascular disease was less pronounced than that in east Asians. South Asians had an increased risk of death observed for coronary heart disease only in individuals with a body mass index greater than 35 (hazard ratio 1.90, 95% confidence interval 1.15 to 3.12).

CONCLUSIONS

Body mass index shows a U shaped association with death from overall cardiovascular disease among east Asians: increased risk of death from cardiovascular disease is observed at lower and higher ranges of body mass index. A high body mass index is a risk factor for mortality from overall cardiovascular disease and for specific diseases, including coronary heart disease, ischaemic stroke, and haemorrhagic stroke in east Asians. Higher body mass index is a weak risk factor for mortality from cardiovascular disease in south Asians.

Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: results from a crossover trial

SCOPE

By increasing blood folate concentrations, folic acid supplementation reduces risk for neural tube defect-affected pregnancies, and lowers homocysteine concentrations. We assessed response of red blood cell (RBC) and serum folate to folic acid supplementation, and examined association of response with the genetic polymorphism C677T of the methylenetetrahydrofolate NAD(P)H (MTHFR) gene.

METHODS AND RESULTS

Randomized, controlled, crossover trial with two folic acid supplement treatment periods and a 30-week washout period. The primary outcome is blood folate (serum and RBC) concentrations. Volunteers (n = 142) aged 18-69 were randomized to two of three doses (0, 200, and 400 μg) of folic acid for 12 weeks. Serum folate response depended on treatment period with significant responses to 200 μg seen only in the second treatment periods (4.4 ng/mL or 3.4 ng/mL). Additionally, serum folate increased as folic acid dose increased to 400 μg (p < 0.01) and response was greater after the washout period (8.7 ng/mL), than after a 6-week run-in (2.3 ng/mL). The differential change attributable to a daily supplement of 400 μg compared to 200 μg was 96.8 ng/mL; while the change attributable to 400 μg compared to 0 μg was 121.4. Increases in RBC folate concentrations with 400 μg occurred within MTHFR gene mutation (C677T); and in the African American group.

CONCLUSION

Serum folate concentration is responsive to modest increases in folic acid intake. RBC folate increases only with higher additional doses of folic acid supplementation, and this is true for each MTHFR C677T genotype.

Body mass index and diabetes in Asia: a cross-sectional pooled analysis of 900,000 individuals in the Asia cohort consortium

BACKGROUND

The occurrence of diabetes has greatly increased in low- and middle-income countries, particularly in Asia, as has the prevalence of overweight and obesity; in European-derived populations, overweight and obesity are established causes of diabetes. The shape of the association of overweight and obesity with diabetes risk and its overall impact have not been adequately studied in Asia.

METHODS AND FINDINGS

A pooled cross-sectional analysis was conducted to evaluate the association between baseline body mass index (BMI, measured as weight in kg divided by the square of height in m) and self-reported diabetes status in over 900,000 individuals recruited in 18 cohorts from Bangladesh, China, India, Japan, Korea, Singapore and Taiwan. Logistic regression models were fitted to calculate cohort-specific odds ratios (OR) of diabetes for categories of increasing BMI, after adjustment for potential confounding factors. OR were pooled across cohorts using a random-effects meta-analysis. The sex- and age-adjusted prevalence of diabetes was 4.3% in the overall population, ranging from 0.5% to 8.2% across participating cohorts. Using the category 22.5-24.9 kg/m²) as reference, the OR for diabetes spanned from 0.58 (95% confidence interval [CI] 0.31, 0.76) for BMI lower than 15.0 kg/m² to 2.23 (95% CI 1.86, 2.67) for BMI higher than 34.9 kg/m². The positive association between BMI and diabetes prevalence was present in all cohorts and in all subgroups of the study population, although the association was stronger in individuals below age 50 at baseline (p-value of interaction<0.001), in cohorts from India and Bangladesh (p<0.001), in individuals with low education (p-value 0.02), and in smokers (p-value 0.03); no differences were observed by gender, urban residence, or alcohol drinking.

CONCLUSIONS

This study estimated the shape and the strength of the association between BMI and prevalence of diabetes in Asian populations and identified patterns of the association by age, country, and other risk factors for diabetes.

Long-term fruit and vegetable change in worksites: Seattle 5 a Day follow-up

OBJECTIVE

To evaluate long-term change in fruit and vegetable intake following a group randomized trial of worksites.

METHODS

Medium-sized blue-collar businesses in the Seattle metropolitan area were recruited. Intake was assessed using serial cross-sectional samples of current workforce at 3 time points. The multilevel 18-month intervention involved partnership with the companies. Long-term follow-up was at 4.4 years postbaseline. Statistical analysis used general linear models, adjusting for worksite random effects.

RESULTS

Initially, 45 worksites were randomized, with 29 agreeing to participate in a new study. Fruits and vegetable intake increased, with larger sustained changes in the intervention worksites, resulting in a long-term differential change of 0.25 servings per day, 95% confidence interval (0.09 to 0.40).

CONCLUSIONS

Intervention sustained small effects at 4 years, including 2 years with no contact. Although effects were not large, this low-intensity intervention approach could provide an important public health model.

A group-randomized tobacco trial among 30 Pacific Northwest colleges: results from the Campus Health Action on Tobacco study

INTRODUCTION

We conducted a group-randomized trial to increase smoking cessation and decrease smoking onset and prevalence in 30 colleges and universities in the Pacific Northwest.

METHODS

Random samples of students, oversampling for freshmen, were drawn from the participating colleges; students completed a questionnaire that included seven major areas of tobacco policies and behavior. Following this baseline, the colleges were randomized to intervention or control. Three interventionists developed Campus Advisory Boards in the 15 intervention colleges and facilitated intervention activities. The freshmen cohort was resurveyed 1 and 2 years after the baseline. Two-years postrandomization, new cross-sectional samples were drawn, and students were surveyed.

RESULTS

At follow-up, we found no significant overall differences between intervention and control schools when examining smoking cessation, prevalence, or onset. There was a significant decrease in prevalence in private independent colleges, a significant increase in cessation among rural schools, and a decrease in smoking onset in urban schools.

DISCUSSION

Intervention in this college population had mixed results. More work is needed to determine how best to reach this population of smokers.

Effects of a multilevel dietary intervention in religious organizations

PURPOSE

This study examined how to improve dietary habits of individuals from the general public.

DESIGN

The Eating for a Healthy Life project was a randomized trial.

SETTING

The study was conducted among members of religious organizations (ROs).

SUBJECTS

Participants were a sample of RO members.

INTERVENTION

The intervention was a multilevel package, based on our previous experience, designed to lower fat and increase fruit and vegetable consumption.

MEASURES

The Eating Behaviors Questionnaire was administered preintervention and postintervention, together with 24-hour food recalls in a randomly selected subset. Analysis. Linear mixed models were used to evaluate the study's intervention, incorporating the design effects of blocking, intraclass correlation within RO, and correlation between the preintervention and postintervention points.

RESULTS

Participants (n = 2175) reported significantly healthier dietary behaviors in intervention ROs at the 12-month follow-up period, compared to participants in the comparison ROs, for a fat scale change of .08 summary scale points and an adjusted intervention effect of .06 overall.

CONCLUSION

Dietary intervention through ROs is a positive and successful method of changing dietary habits.

Mediation of adult fruit and vegetable consumption in the National 5 A Day for Better Health community studies

BACKGROUND

The 5 A Day for Better Health community studies demonstrated in randomized trials the efficacy of population-based strategies to increase fruit and vegetable consumption in diverse geographic areas and settings.

PURPOSE

Mediation analysis can help to elucidate the theoretical basis of changing dietary habits. This is important for informing more powerful cancer prevention and control interventions to achieve broad public health impact.

METHODS

Five sites that focused on adults were included in mediation analyses to determine whether theoretically derived constructs assessed at baseline and follow-up contributed to explaining change in fruit and vegetable (F&V) consumption. These variables were knowledge, self-efficacy, and autonomy/responsibility. Stage of change also was considered as a potential moderating variable.

RESULTS

Self-efficacy and knowledge of the 5 A Day recommendation increased in those who received the interventions and were positively associated with higher F&V. Mediation of intervention effect was demonstrated for these variables. Autonomy/responsibility did not meet the criteria for mediation. There was no evidence of differential effect of mediators according to baseline stage.

CONCLUSIONS

The present study findings provide strong support for mediation of F&V consumption by two variables: self-efficacy and knowledge. The authors discuss the findings in relation to study limitations and future research directions.

SELDI-TOF MS whole serum proteomic profiling with IMAC surface does not reliably detect prostate cancer

BACKGROUND

The analysis of bodily fluids using SELDI-TOF MS has been reported to identify signatures of spectral peaks that can be used to differentiate patients with a specific disease from normal or control patients. This report is the 2nd of 2 companion articles describing a validation study of a SELDI-TOF MS approach with IMAC surface sample processing to identify prostatic adenocarcinoma.

METHODS

We sought to derive a decision algorithm for classification of prostate cancer from SELDI-TOF MS spectral data from a new retrospective sample cohort of 400 specimens. This new cohort was selected to minimize possible confounders identified in the previous study described in the companion paper.

RESULTS

The resulting new classifier failed to separate patients with prostate cancer from biopsy-negative controls; nor did it separate patients with prostate cancer with Gleason scores <7 from those with Gleason scores > or =7.

CONCLUSIONS

In this, the 2nd stage of our planned validation process, the SELDI-TOF MS-based protein expression profiling approach did not perform well enough to advance to the 3rd (prospective study) stage. We conclude that the results from our previous studies-in which differentiation between prostate cancer and noncancer was demonstrated-are not generalizable. Earlier study samples likely had biases in sample selection that upon removal, as in the present study, resulted in inability of the technique to discriminate cancer from noncancer cases.

Analytical validation of serum proteomic profiling for diagnosis of prostate cancer: sources of sample bias

BACKGROUND

This report and a companion report describe a validation of the ability of serum proteomic profiling via SELDI-TOF mass spectrometry to detect prostatic cancer. Details of this 3-stage process have been described. This report describes the development of the algorithm and results of the blinded test for stage 1.

METHODS

We derived the decision algorithm used in this study from the analysis of serum samples from patients with prostate cancer (n = 181) and benign prostatic hyperplasia (BPH) (n = 143) and normal controls (n = 220). We also derived a validation test set from a separate, geographically diverse set of serum samples from 42 prostate cancer patients and 42 controls without prostate cancer. Aliquots were subjected to randomization and blinded analysis, and data from each laboratory site were subjected to the decision algorithm and decoded.

RESULTS

Using the data collected from the validation test set, the decision algorithm was unsuccessful in separating cancer from controls with any predictive utility. Analysis of the experimental data revealed potential sources of bias.

CONCLUSION

The ability of the decision algorithm to successfully differentiate between prostate cancer, BPH, and control samples using data derived from serum protein profiling was compromised by bias.

A note on the estimation of the multinomial logistic model with correlated responses in SAS

We show how multinomial logistic models with correlated responses can be estimated within SAS software. To achieve this, random effects and marginal models are introduced and the respective SAS code is given. An example data set on physicians' recommendations and preferences in traumatic brain injury rehabilitation is used for illustration. The main motivation for this work are two recent papers that recommend estimating multinomial logistic models with correlated responses by using a Poisson likelihood which is statistically correct but computationally inefficient.

Ultrasensitive detection and characterization of posttranslational modifications using surface-enhanced Raman spectroscopy

Posttranslational modification (PTM) of proteins is likely to be the most common mechanism of altering the expression of genetic information. It is essential to characterize PTMs to establish a complete understanding of the activities of proteins. Here, we present a sensitive detection method using surface-enhanced Raman spectroscopy (SERS) that can detect PTMs from as little as zeptomoles of peptide. We demonstrate, using model peptides, the ability of SERS to detect a variety of protein modifications, such as acetylation, trimethylation, phosphorylation, and ubiquitination. In addition, we show the capability to obtain positional information for modifications such as trimethylation and phosphorylation using SERS and wavelet decomposition data analysis techniques. We further show that it is possible to apply SERS to detect PTMs from biological samples such as histones. We envision that this detection method might be a valuable technique that is complementary to mass spectrometry in obtaining orthogonal chemical and modification-specific information from biological samples at sensitive levels.

5-year urinary and sexual outcomes after radical prostatectomy: results from the prostate cancer outcomes study

PURPOSE

Prior studies of postoperative outcomes following radical prostatectomy have been limited by selection bias and short-term followup. In this study we assessed temporal changes in urinary and sexual function up to 5 years following radical prostatectomy in a population based cohort.

MATERIALS AND METHODS

A sample of 1,288 men with localized prostate cancer who underwent radical prostatectomy and completed a baseline survey within 6 to 12 months of diagnosis were included in the analysis. Two and 5-year functional and quality of life data were collected, as was information on the use of erectile aids. Temporal functional changes and potentially confounding or modifying factors were assessed using longitudinal regression models.

RESULTS

Of these men 14% reported frequent urinary leakage or no urinary control 60 months after diagnosis, which was slightly higher than the 10% reporting incontinence at 24 months (p = 0.007). At 60 months 28% of the men had erections firm enough for intercourse compared with 22% at 24 months (p = 0.003). Sildenafil was the most commonly used erectile aid (43% ever used) and 45% of users reported that it helped "somewhat" or "a lot."

CONCLUSIONS

Urinary and sexual dysfunction were common 5 years following radical prostatectomy in this large, community based cohort of prostate cancer survivors. While a small minority of subjects experienced changes in urinary or sexual function between years 2 and 5 after prostatectomy, functional outcomes remained relatively stable in the majority of participants.

Evaluation of serum protein profiling by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry for the detection of prostate cancer: I. Assessment of platform reproducibility

BACKGROUND

Protein expression profiling for differences indicative of early cancer has promise for improving diagnostics. This report describes the first stage of a National Cancer Institute/Early Detection Research Network-sponsored multiinstitutional evaluation and validation of this approach for detection of prostate cancer.

METHODS

Two sequential experimental phases were conducted to establish interlaboratory calibration and standardization of the surface-enhanced laser desorption (SELDI) instrumental and assay platform output. We first established whether the output from multiple calibrated Protein Biosystem II SELDI-ionization time-of-flight mass spectrometry (TOF-MS) instruments demonstrated acceptable interlaboratory reproducibility. This was determined by measuring mass accuracy, resolution, signal-to-noise ratio, and normalized intensity of three m/z "peaks" present in a standard pooled serum sample. We next evaluated the ability of the calibrated and standardized instrumentation to accurately differentiate between selected cases of prostate cancer and control by use of an algorithm developed from data derived from a single site 2 years earlier.

RESULTS

When the described standard operating procedures were established at all laboratory sites, the across-laboratory measurements revealed a CV for mass accuracy of 0.1%, signal-to-noise ratio of approximately 40%, and normalized intensity of 15-36% for the three pooled serum peaks. This was comparable to the intralaboratory measurements of the same peaks. The instrument systems were then challenged with sera from a selected group of 14 cases and 14 controls. The classification agreement between each site and the established decision algorithm were examined by use of both raw peak intensity boosting and ranked peak intensity boosting. All six sites achieved perfect blinded classification for all samples when boosted alignment of raw intensities was used. Four of six sites achieved perfect blinded classification with ranked intensities, with one site passing the criteria of 26 of 28 correct and one site failing with 19 of 28 correct.

CONCLUSIONS

These results demonstrate that "between-laboratory" reproducibility of SELDI-TOF-MS serum profiling approaches that of "within-laboratory" reproducibility as determined by measuring discrete m/z peaks over time and across laboratories.

A short acculturation scale for Mexican-American populations

Acculturation is important to examine variables that differentiate members of ethnic groups so that interventions can be appropriately targeted. By using a population-based sample of Mexican-origin adults, we sought to validate an acculturation scale for Mexican-American populations. The acculturation instrument included eight items adapted from the Acculturation Rating Scale for Mexican Americans (ARSMA). By using principal component analysis, we calculated eigenvalues for the eight items. The first principal component accounted for 66% of the variance. Language spoken most of the time, by itself, explained 62.4% of the variance of the full model, whereas birthplace, by itself, accounted for 74%. Slight increases in correlation values were observed beyond a four-item model that included language spoken most of the time, language thought, ethnic identity, and birthplace. Future studies should compare this scale with other multidimensional scales.

Evaluation of Community-Intervention Trials via Generalized Linear Mixed Models

In community-intervention trials, communities, rather than individuals, are randomized to experimental arms. Generalized linear mixed models offer a flexible parametric framework for the evaluation of community-intervention trials, incorporating both systematic and random variations at the community and individual levels. We propose here a simple two-stage inference method for generalized linear mixed models, specifically tailored to the analysis of community-intervention trials. In the first stage, community-specific random effects are estimated from individual-level data, adjusting for the effects of individual-level covariates. This reduces the model approximately to a linear mixed model with the unit of analysis being community. Because the number of communities is typically small in community-intervention studies, we apply the small-sample inference method of Kenward and Roger (1997, Biometrics53, 983-997) to the linear mixed model of second stage. We show by simulation that, under typical settings of community-intervention studies, the proposed approach improves the inference on the intervention-effect parameter uniformly over both the linearized mixed-effect approach and the adaptive Gaussian quadrature approach for generalized linear mixed models. This work is motivated by a series of large randomized trials that test community interventions for promoting cancer preventive lifestyles and behaviors.

Baseline data and design for a randomized intervention study of dietary change in religious organizations

BACKGROUND

Reducing dietary fat has been identified as a potential means of preventing chronic disease. Several studies have identified methods of changing dietary fat consumption in small, intensive intervention settings. Fewer studies have examined how to improve dietary habits of individuals in the general public.

METHODS

The Eating for a Healthy Life (EHL) project was a randomized trial [n = 40 religious organizations (ROs) and 2175 individuals, 1099 in intervention]. The study tested an intervention package of self-help books, motivational messages, and social interactions designed to change dietary behaviors (lowering fat, increasing fruit and vegetable consumption) among members of religious organizations aged 18 and over. The primary outcomes are fat- and fruit- or vegetable-related behaviors measured using the Fat and Fiber Behavior (FFB) Questionnaire.

RESULTS

Religious organizations and their members participated fully in the initial study activities.

CONCLUSIONS

This study will support a rigorous test of the intervention package.

Is religious orientation associated with fat and fruit/vegetable intake?

We explored associations of religious orientation with dietary behavior among participants in the Eating for a Healthy Life Study (EHL), a randomized low-fat, high-fruit/vegetable dietary intervention trial in religious organizations. Data in this report are from baseline telephone surveys of 2,375 people, which assessed dietary behaviors (Fat- and Fiber-Related Diet Behavior Questionnaire) and religiosity (Allport-Ross Religious Orientation Scale). After adjusting for demographic characteristics, higher extrinsic (socially motivated) religious orientation was positively associated with low-fat dietary fat behaviors (P=.0438). No associations were observed for dietary behaviors and intrinsic (life based on religious beliefs) religious orientation. These results support further exploration of religious orientation's potential influence on dietary behaviors and its applicability to dietary interventions.

Use of Pap test among Hispanics and non-Hispanic whites in a rural setting

BACKGROUND

Hispanic women in the United States have a higher incidence of invasive cervical cancer than non-Hispanic whites. A key factor related to the relatively high incidence is the underutilization of cancer-screening services. Several previous investigations have reported that Hispanic women are less likely to comply with screening recommendations for Pap testing; some have identified factors that are associated with non-compliance with screening recommendations.

METHODS

Using baseline personal interview data from a randomized community trial on cancer prevention in a rural area, we assessed the association between health barriers and non-compliance with cervical screening recommendations.

RESULTS

Among Hispanic women (n = 382), those with a lower level of acculturation were more likely than highly acculturated Hispanic and non-Hispanic white women (n = 385) to report personal barriers as reasons for not getting an initial or subsequent screening exam. Such barriers include fear of finding cancer, fear of finding diseases other than cancer, and embarrassment about receiving a physical exam. Certain structural barriers, such as cost of care, no time off work, and lack of transportation, were reported to be associated with non-compliance with routine cervical cancer screening, especially among non-Hispanic white women.

CONCLUSIONS

Future research should examine barriers related to initial and subsequent screening among Hispanics with varying levels of acculturation.

Smoke exposure, histologic type and geography-related differences in the methylation profiles of non-small cell lung cancer

Aberrant methylation of several known or putative tumor suppressor genes occurs frequently during the pathogenesis of lung cancers. There are major smoke exposure, histology, geography and gender-related changes in non-small cell lung cancer (NSCLC). We investigated smoking-related, histologic, geographic and gender differences in the methylation profiles of resected NSCLCs. We examined 514 cases of NSCLC and 84 corresponding nonmalignant lung tissues from 4 countries (USA, Australia, Japan and Taiwan) for the methylation status of 7 genes known to be frequently methylated in lung cancers [p16, RASSF1A (RAS association domain family 1), APC, RARbeta, CDH13, MGMT and GSTP1]. Multivariate analyses were used for data analysis. Adenocarcinoma was the major histologic type in women and never smokers; analyses that involved smoke exposure and gender were limited to this histology. Our major findings are a) methylation status of any single gene was largely independent of methylation status of other genes; b) the rates of methylation of p16 and APC and the mean Methylation Index (MI), a reflection of the overall methylation status, were significantly higher in ever smokers than in never smokers; c) the mean MI of tumors arising in former smokers was significantly lower than the mean of current smokers; d) the methylation rates of APC, CDH13 and RARbeta were significantly higher in adenocarcinomas than in squamous cell carcinomas; e) methylation rates of MGMT and GSTP1 were significantly higher in the USA and Australian cases than in those from Japan and Taiwan; and (f) no significant gender-related differences in methylation patterns were noted. Our findings demonstrate important smoke exposure, histologic type and geography-related differences in the methylation profiles of NSCLC tumors.

An Automated Peak Identification/Calibration Procedure for High-Dimensional Protein Measures From Mass Spectrometers

Discovery of “signature” protein profiles that distinguish disease states (eg, malignant, benign, and normal) is a key step towards translating recent advancements in proteomic technologies into clinical utilities. Protein data generated from mass spectrometers are, however, large in size and have complex features due to complexities in both biological specimens and interfering biochemical/physical processes of the measurement procedure. Making sense out of such high-dimensional complex data is challenging and necessitates the use of a systematic data analytic strategy. We propose here a data processing strategy for two major issues in the analysis of such mass-spectrometry-generated proteomic data: (1) separation of protein “signals” from background “noise” in protein intensity measurements and (2) calibration of protein mass/charge measurements across samples. We illustrate the two issues and the utility of the proposed strategy using data from a prostate cancer biomarker discovery project as an example.

Selected statistical issues in group randomized trials

Group randomized trials (GRTs) in public health research typically use a small number of randomized groups with a relatively large number of participants per group. Two fundamental features characterize GRTs: a positive correlation of outcomes within a group, and the small number of groups. Appropriate consideration of these fundamental features is essential for design and analysis. This paper presents the fundamental features of GRTs and the importance of considering these features in design and analysis. It also reviews and contrasts the main analytic methods proposed for GRTs, emphasizing the assumptions required to make these methods valid and efficient. Also discussed are various design issues, along with guidelines for choosing among them. A real data example illustrates these issues and methods.

Seattle 5 a Day worksite program to increase fruit and vegetable consumption

BACKGROUND

5 a Day for Better Health is a simple message encouraging people to eat more fruits and vegetables. The Seattle 5 a Day worksite investigators designed and evaluated an intervention, organized on stages of behavioral change, to increase worksitewide fruit and vegetable consumption.

METHODS

We recruited 28 worksites with cafeterias and randomized 14 to intervention and 14 to control. The intervention addressed both changes in the work environment and individual level behavior change. In each worksite, an employee advisory board, with study interventionist assistance, implemented the program. By surveying cross-sectional samples of 125 employees per worksite, we compared worksite mean fruit and vegetable consumption at 2-year follow-up with that at baseline. Unobtrusive site-level indicators including plate observation and cafeteria checklist were also used.

RESULTS

The difference at 2 years was 0.5 for the intervention worksites and 0.2 for the control worksites, with an intervention effect of 0.3 daily serving (P < 0.05). Other measures of fruit and vegetable consumption, including unobtrusive indicators, supported the effectiveness of the intervention.

CONCLUSIONS

This simple 5 a Day intervention is feasible and acceptable for use in worksites with cafeterias. There was a significant differential increase in fruit and vegetable consumption in the intervention worksites. This kind of worksite intervention can achieve important health benefits on a population basis, because of its potential to reach large numbers of people.

Precision and bias of food frequency-based measures of fruit and vegetable intakes

Accurate assessment of fruit and vegetable intakes is critical for cancer control research and public health surveillance. This report examines the bias and precision of two commonly used food frequency questionnaire methods to assess fruit and vegetable intakes: (a) the 5 A Day method, based on seven items; and (b) the summation method, based on adding total servings of all fruit and vegetable items on a comprehensive (100+ item) food frequency questionnaire. Data are from three studies in which 24-h dietary recalls, food records, or serum carotenoid concentrations could be used as criterion measures (n = 260, 1031, and 342). Studies differed markedly in distributions of participants' age, race/ethnicity, sex, and socioeconomic status. Mean intakes of total fruit and vegetables based on the 5 A Day method were consistently lower than those from either the summation method (3.11 versus 4.06), 24-h recalls (3.32 versus 4.07), or food records (3.11 versus 3.46; all P < 0.01), and this was due primarily to underestimates of vegetable intake. Correlations of the 5 A Day and summation measures with all criterion measures were similar and were consistently higher for fruit (range, 0.33-0.57) than for vegetables (range, 0.24-0.32). These results, which were consistent across diverse participant samples, suggest that the 5 A Day method yields both biased and imprecise measures of vegetable intake and that research to improve this measure is needed.

The relationship between organizational characteristics and the adoption of workplace smoking policies

Organizational-level variables that are hypothesized to influence the level of smoking policy restrictions and the prevalence of smoking control activities were tested in a sample of 1 14 worksites that participated in the Working Well Trial, a national trial of worksite health promotion. Predictors related to more restrictive policies included smaller size, larger percentage of white-collar workers, larger number of complaints about environmental tobacco smoke, less complexity, more formalization, and having a CEO who valued health and employees' well-being. The number of smoking control activities offered in a worksite was predicted by having a larger blue-collar workforce, a higher percentage of female employees, higher levels of workforce stability, and a CEO who valued health and employees' well-being. Efforts to identify predictors of companies' adoption and implementation of workplace-based policies and interventions are an important part of tobacco control efforts and will enhance future intervention and research efforts.

Seattle 5-a-Day Work-Site Project: process evaluation

The Seattle 5-a-Day Work-Site Project developed a community-based intervention to increase fruit and vegetable intake, using both environmental (including cafeteria and work-site-wide events) and individual strategies. The Employee Advisory Board developed its own protocol from a common skeleton and a minimum set of activities. Small work sites and work sites with fewer female employees delivered more displays, posters, and table tents per employee (p < .01 and p < .05, respectively). Dose was neither related to use of the intervention nor to change in fruit and vegetable intake. Use of informational materials increased fruit and vegetable intake in the cohort of employees with both baseline and follow-up data (p = .05). The intervention was associated both with increased employee use of the intervention (activities and materials) and with increased intake of fruit and vegetables. Work sites with medium average baseline intake were the most responsive. These findings can guide the development of more efficient community-based dietary interventions.

Validity of short food frequency questionnaires used in cancer chemoprevention trials: results from the Prostate Cancer Prevention Trial

Here, we describe the measurement characteristics of a 13-item dietary screener used in the Prostate Cancer Prevention Trial. We used data from 10,913 men who completed the 13-item dietary screener, a food frequency questionnaire (FFQ), and questionnaires on demographic and health-related characteristics and from 146 men who also completed multiple 24-h dietary recalls in a substudy. The analyses in this report focused on percentage energy from fat and saturated fat and used the mean estimates from the dietary recalls as the criterion measures. Absolute nutrient estimates from the screener were about one-third of the estimates from the recalls and the FFQ. Validity was defined as the Pearson correlation of the criterion measures of fat with the corresponding measures from the FFQ and the screener. The FFQ was a statistically significantly more precise measure of percentage energy from fat (r = 0.71) and saturated fat (r = 0.72) than was the screener (r = 0.50 and 0.53, respectively). There were also statistically significant differences in how well these instruments could detect variation in dietary fat across various participant characteristics, suggesting that the screener may not perform as well as the FFQ across demographic strata such as education (P < 0.001). The results from this study suggest that the use of short dietary screeners as the sole assessment instrument may result in a serious loss of information regarding important exposures (e.g., fat intake) and lost opportunities to enhance our knowledge regarding dietary factors and cancer risk.

Impact of the Working Well Trial on the worksite smoking and nutrition environment

This article reports the effect of a worksite cancer control intervention on aspects of the physical and social environment related to dietary and smoking behaviors of employees. Data are from 111 intervention and control worksites that participated in the Working Well Trial. Employee surveys and interviews with key organizational informants assessed environmental and normative changes relevant to nutrition and tobacco use. Results indicated significant effects of the intervention on all nutrition outcomes: access to healthy food, nutritional information at work, and social norms regarding dietary choice. Significant benefits were not found for smoking norms or smoking policies. However, changes occurred in both the control and intervention sites on these variables. This first large analysis of environmental and normative effects of a worksite intervention is consistent with the employee behavior change findings for the trial and serves as a model for future analyses of multilevel worksite health promotion programs.

Validity of methods used to assess vitamin and mineral supplement use

Assessing vitamin and mineral supplement use is important because supplement use per se is an exposure of interest for the risk of several chronic diseases and because supplements contribute a large proportion of total (diet plus supplement) micronutrient intake, another important exposure in epidemiologic research. Unfortunately, little is known about methods for obtaining valid information about supplement use. The authors conducted a validation study in 1996 comparing supplement data collected in a telephone interview and from a self-administered questionnaire with data derived from a detailed, in-person interview and transcription of the labels of supplement bottles (i.e., a gold standard) among adult supplement users in Washington State (n = 104). Spearman correlation coefficients comparing average daily supplemental vitamin and mineral intake from the interview or questionnaire with the gold standard ranged from 0.76 (95% confidence interval 0.66-0.83) for vitamin C to 0.08 (95% confidence interval -0.14 to 0.29) for iron, with a mean of about 0.5. The principal sources of error were inaccurate assumptions about the micronutrient composition of multiple vitamins and respondent confusion regarding the distinction between multiple vitamins and single supplements. These results suggest that commonly used epidemiologic methods of assessing supplement use may incorporate significant amounts of error in estimates of some nutrients.

A comparison of statistical methods for clustered data analysis with Gaussian error

We investigate by simulation the properties of four different estimation procedures under a linear model for correlated data with Gaussian error: maximum likelihood based on the normal mixed linear model; generalized estimating equations; a four-stage method, and a bootstrap method that resamples clusters rather than individuals. We pay special attention to the group randomized trials where the number of independent clusters is small, cluster sizes are big, and the correlation within the cluster is weak. We show that for balanced and near balanced data when the number of independent clusters is small (< or = 10), the bootstrap is superior if analysts do not want to impose strong distribution and covariance structure assumptions. Otherwise, ML and four-stage methods are slightly better. All four methods perform well when the number of independent clusters reaches 50.

Community organization to promote breast cancer screening ordering by primary care physicians

Community organization has been viewed as a promising approach to changing preventive behaviors. We evaluated the impact of community organization strategies to promote breast cancer screening ordering by primary care physicians in Washington State. Physicians practicing in two intervention and two control communities were surveyed by mail pre-intervention (1989) and post-intervention (1993). Intervention activities targeting the health care sector included the formation of local physician planning groups, a series of informational mailings, medical office staff training sessions, and reminder system support. There were no significant post-intervention differences in the self-reported mammography ordering of physicians practicing in the intervention and control areas. Over the four-year study period, the proportions of physicians who ordered regular mammography increased by 36%. By 1993, over 80% of the respondents routinely used mammographic screening. Concerns about the high price of mammograms and inadequate insurance coverage were significantly reduced over time in both community pairs. Also, use of patient reminder systems increased significantly between 1989 and 1993. Secular trends resulting from diffusion of strategies to promote mammography were responsible for increases in physician ordering of the procedure. Year 2000 goals for breast cancer screening use by physicians may already have been met in some communities.

Using administrative data to describe casemix: a comparison with the medical record

We compared the coding of comorbid conditions in an administrative database to that found in medical records for 485 men who had undergone a prostatectomy. Only a few specific conditions showed good agreement between charts and claims. Most showed poor agreement and appeared more frequently in the chart. A comorbidity index calculated from each of these sources was used to explore the differences in mortality for patients who had undergone transurethral vs open prostatectomy. The claims-based comorbidity index most often underestimated the index from the chart. Proportional hazards analysis showed that models including either comorbidity index were better than those without an index and models with information from both indices were best. No analysis eliminated the effect of type of prostatectomy on long-term mortality. Claims-based measures of comorbidity tend to underrepresent some conditions but may be an acceptable first step in controlling for differences across patient populations.

Internal validation of Medicare claims data

The Medicare database is commonly used for epidemiology and health services research, but validation of its data by chart review or questionnaire may be difficult and expensive. Since hospital and physician bills are independent in Medicare, however, these two data sources can be used to supplement and corroborate each other. This "internal validation" is illustrated here for hip fracture and prostatectomy. Agreement of the hospital and physician data streams regarding site of hip fracture (neck vs other), treatment of hip fracture (internal fixation vs arthroplasty), and type of prostatectomy (transurethral resection of prostate, open, or radical) was excellent, with percentage of agreement generally between 89% and 99%, and kappa statistics typically between 0.74 and 0.95. When validation with outside data sources is not readily available, such internal validation of Medicare data may be valuable.

An assessment of radical prostatectomy. Time trends, geographic variation, and outcomes. The Prostate Patient Outcomes Research Team

OBJECTIVES

To examine temporal trends and geographic variation in radical prostatectomy rates and short-term outcomes.

DESIGN

Population-based study of radical prostatectomy for the years 1984 through 1990. Poisson regression was used to estimate temporal and regional effects.

SETTING

The 50 states and the District of Columbia.

PARTICIPANTS

A 20% national sample of male Medicare beneficiaries aged 65 years or older.

MAIN OUTCOME MEASURES

Rate of radical prostatectomy; 30-day mortality; and major cardiopulmonary complications, vascular complications, or surgical repairs within 30 days of radical prostatectomy.

RESULTS

A total of 10,598 radical prostatectomies were identified. The adjusted rate of radical prostatectomy in 1990 was 5.75 times that in 1984. The relative increase was similar in all age groups. Substantial geographic variation existed in rates from 1988 through 1990: all states in the New England and Mid-Atlantic regions had rates equal to or below 60 per 100,000 male Medicare beneficiaries, while all states in the Pacific and Mountain regions had rates equal to or above 130 per 100,000. The mortality and morbidity after radical prostatectomy are not trivial for older men (aged 75 years and older)--almost 2% died and nearly 8% suffered major cardiopulmonary complications within 30 days of the operation.

CONCLUSION

The sharp increase and wide geographic variation in radical prostatectomy rates make the evaluation of this surgical procedure a pressing issue. The rising rate of radical prostatectomy among men aged 75 years and older merits special attention.

Further study of the increased mortality following transurethral prostatectomy: a chart-based analysis

Previous studies using large administrative databases found an elevated relative risk of reoperation and death after transurethral resection of the prostate compared to open prostatectomy. To investigate whether differences in case-mix unmeasured by administrative data explained this finding, we reviewed the charts of 485 patients who had undergone prostatectomy (236 open and 249 transurethral) at the Health Science Centre, Winnipeg, Manitoba, Canada between 1974 and 1980. Data from patient histories, physical examinations and laboratory evaluations were abstracted and used to control for case-mix in models comparing the rates of reoperation and mortality after transurethral versus open prostatectomy. Several models were specified. In all models the relative risk of dying after transurethral prostatectomy remained elevated (1.36 to 1.89), as did the risk for reoperation (3.62). A prospective trial is needed to establish the relative safety and effectiveness of transurethral and open prostatectomy.