Estimating Cancer Screening Sensitivity and Specificity Using Healthcare Utilization Data: Defining the Accuracy Assessment Interval.

The effectiveness and efficiency of cancer screening in real-world settings depend on many factors, including test sensitivity and specificity. Outside of select experimental studies, not everyone receives a gold standard test that can serve as a comparator in estimating screening test accuracy. Thus, many studies of screening test accuracy use the passage of time to infer whether or not cancer was present at the time of the screening test, particularly for patients with a negative screening test. We define the accuracy assessment interval as the period of time after a screening test that is used to estimate the test's accuracy. We describe how the length of this interval may bias sensitivity and specificity estimates. We call for future research to quantify bias and uncertainty in accuracy estimates and to provide guidance on setting accuracy assessment interval lengths for different cancers and screening modalities.

Association of Patient Demographic Characteristics and Insurance Status With Survival in Cancer Randomized Clinical Trials With Positive Findings.

Importance: Few new treatments tested in phase 3 cancer randomized clinical trials show an overall survival benefit. Although understanding whether the benefits are consistent among all patient groups is critical for informing guideline care, individual trials are designed to assess the benefits of experimental treatments among all patients and are too small to reliably determine whether treatment benefits apply to demographic or insurance subgroups. Objective: To systematically examine whether positive treatment effects in cancer randomized clinical trials apply to specific demographic or insurance subgroups. Design, Setting, and Participants: Cohort study of pooled patient-level data from 10 804 patients in SWOG Cancer Research Network clinical treatment trials reported from 1985 onward with superior overall survival for those receiving experimental treatment. Patients were enrolled from 1984 to 2012. Maximum follow-up was 5 years. Main Outcomes and Measures: Interaction tests were used to assess whether hazard ratios (HRs) for death comparing standard group vs experimental group treatments were associated with age (≥65 vs <65 years), race/ethnicity (minority vs nonminority populations), sex, or insurance status among patients younger than 65 years (Medicaid or no insurance vs private insurance) in multivariable Cox regression frailty models. Progression- or relapse-free survival was also examined. Data analyses were conducted from August 2019 to February 2020. Results: In total, 19 trials including 10 804 patients were identified that reported superior overall survival for patients randomized to experimental treatment. Patients were predominantly younger than 65 years (67.3%) and female (66.3%); 11.4% were black patients, and 5.7% were Hispanic patients. There was evidence of added survival benefits associated with receipt of experimental therapy for all groups except for patients with Medicaid or no insurance (HR, 1.23; 95% CI, 0.97-1.56; P = .09) compared with those with private insurance (HR, 1.66; 95% CI, 1.44-1.92; P < .001; P = .03 for interaction). Receipt of experimental treatment was associated with reduced added overall survival benefits in patients 65 years or older (HR, 1.21; 95% CI, 1.11-1.32; P < .001) compared with patients younger than 65 years (HR, 1.41; 95% CI, 1.30-1.53; P < .001; P = .01 for interaction), although both older and younger patients appeared to strongly benefit from receipt of experimental treatment. The progression- or relapse-free survival HRs did not differ by age, sex, or race/ethnicity but differed between patients with Medicaid or no insurance (HR, 1.32; 95% CI, 1.06-1.64; P = .01) vs private insurance (HR, 1.74; 95% CI, 1.54-1.97; P < .001; P = .03 for interaction). Conclusions and Relevance: Patients with Medicaid or no insurance may have smaller added benefits from experimental therapies compared with standard treatments in clinical trials. A better understanding of the quality of survivorship care that patients with suboptimal insurance receive, including supportive care and posttreatment care, could help establish how external factors may affect outcomes for these patients.

Healthcare utilization and cost of care in elderly breast cancer patients enrolled in SWOG clinical trials.

IMPORTANCE: Patients with cancer are at risk for unplanned hospitalizations during treatment which can increase the cost of care. OBJECTIVES: To determine demographic and clinical factors associated with healthcare utilization and costs among clinical trial participants. DESIGN, SETTING, AND PATIENTS: We conducted a retrospective analysis among breast cancer patients over the age of 65 treated on SWOG clinical trials from 1999 to 2011 with trial data linked to Medicare claims. MAIN OUTCOMES AND MEASURES: The outcomes were healthcare utilization (emergency room visits (ER), hospitalizations) and costs from Medicare Claims. Demographic, clinical, and prognostic factors were captured from clinical trial records. We identified cardiovascular comorbidities/risk factors (CVD-RFs) of diabetes, hypertension, hypercholesterolemia, and coronary artery disease (CAD) from Medicare claims. Multivariable logistic and linear regression were used to assess the association between CVD-RFs and outcomes. RESULTS: Among the 708 patients included in the analysis, 160 (22.6%) experienced 234 separate hospitalizations, and 193 (27.3%) experienced 311 separate ER visits. Black race was associated with an increase in hospitalizations (OR [95% CI], 2.52 [1.10-5.79], p = 0.03), but not emergency room visits compared to white race. Diabetes, hypertension, hypercholesterolemia, and CAD were all independently associated with increased risk of both hospitalizations and ER visit. Hypertension had the strongest association, with more than a threefold risk of hospitalization for those with hypertension compared to those without (OR [95% CI], 3.16 [1.85-5.40], p < 0.001). For those with ≥ 3 RFs, the risk of hospitalization was nearly 3 times greater compared to 0 or 1 CVD-RFs (OR [95% CI], 2.74 [1.71-4.38], p < 0.001). Similar results were seen for ER visits. In the first 12 months after trial registration, patients with diabetes ($38,324 vs $30,923, 23.9% increase, p = 0.05), hypercholesterolemia ($34,168 vs $30,661, 11.4% increase, p = 0.02), and CAD ($37,781 vs $31,698, 19.2% increase, p = 0.04) had statistically significantly higher total healthcare costs. Additionally, those with ≥ 2 significant CVD-RFs ($35,353 vs. $28,899, 22.3% increase, p = 0.005) had statistically significantly higher total healthcare costs. CONCLUSIONS: Among participants treated on clinical trials, black race and presence of multiple cardiovascular comorbidities was associated with a substantial increase in ER visits, hospitalizations and healthcare costs. Efforts to reduce unplanned hospitalizations should focus on this high-risk group.

Long-Term Outcomes and Cost-Effectiveness of Breast Cancer Screening With Digital Breast Tomosynthesis in the United States.

BACKGROUND: Digital breast tomosynthesis (DBT) is increasingly being used for routine breast cancer screening. We projected the long-term impact and cost-effectiveness of DBT compared to conventional digital mammography (DM) for breast cancer screening in the United States. METHODS: Three Cancer Intervention and Surveillance Modeling Network breast cancer models simulated US women ages 40 years and older undergoing breast cancer screening with either DBT or DM starting in 2011 and continuing for the lifetime of the cohort. Screening performance estimates were based on observational data; in an alternative scenario, we assumed 4% higher sensitivity for DBT. Analyses used federal payer perspective; costs and utilities were discounted at 3% annually. Outcomes included breast cancer deaths, quality-adjusted life-years (QALYs), false-positive examinations, costs, and incremental cost-effectiveness ratios (ICERs). RESULTS: Compared to DM, DBT screening resulted in a slight reduction in breast cancer deaths (range across models 0-0.21 per 1000 women), small increase in QALYs (1.97-3.27 per 1000 women), and a 24-28% reduction in false-positive exams (237-268 per 1000 women) relative to DM. ICERs ranged from $195 026 to $270 135 per QALY for DBT relative to DM. When assuming 4% higher DBT sensitivity, ICERs decreased to $130 533-$156 624 per QALY. ICERs were sensitive to DBT costs, decreasing to $78 731 to $168 883 and $52 918 to $118 048 when the additional cost of DBT was reduced to $36 and $26 (from baseline of $56), respectively. CONCLUSION: DBT reduces false-positive exams while achieving similar or slightly improved health benefits. At current reimbursement rates, the additional costs of DBT screening are likely high relative to the benefits gained; however, DBT could be cost-effective at lower screening costs.

Osteoporosis in colorectal cancer survivors: analysis of the linkage between SWOG trial enrollees and Medicare claims.

To explore the rates of osteoporosis (diagnosis and screening) and fractures in colorectal cancer survivors (CRCS), records of clinical trial enrollees was linked to Medicare. Female/male risk of fracture in CRCS is 74% higher than general population. Less than 30% of male and female CRCS receive osteoporosis screening. Osteoporosis is a significant morbidity in CRCS. INTRODUCTION: In the USA, the population of colorectal cancer survivors (CRCS) is on the rise. Calcium and vitamin D are the common thread between colorectal cancer and osteoporosis. We set to explore the patterns and prevalence of osteoporosis (OP) and osteoporotic fractures (OF) in CRCS who received fluorouracil-based therapy on SWOG trials. METHODS: Data for CRCS from three SWOG phase III treatment trials between 1994 and 2000 (N = 3775) were linked to Medicare claims (N = 1233). OP was identified using ICD9 and HCPCS codes; OF was defined using a more restricted set of codes. We compared patterns of OP, OF, and screening for OP by gender in CRCS. Given the gender disparities in the rates of OP and OF, we used data from the National Health Interview Survey (NHIS) and the National Hospital Discharge Survey (NHDS) to assess the ratio of OF in females and males in general population. RESULTS: Forty-seven percent of females and 15% of men CRCS had OP claims. Female CRCS were more likely than males to have OP (HR = 4.76 [3.77-6.01], p < 0.0001) and OF (HR = 2.64 [2.04-3.42], p < 0.0001). In the general population, the female to male ratio of OF was 1.67 as opposed to 2.90 in CRCS, indicating a significantly larger gender disparity of OF in CRCS (p < 0.001). Only 7% of men and 27% of women CRCS had OP screening. CONCLUSION: Despite a low rate of OP screening, the gender disparity of OF in CRCS is more pronounced than the general population. These findings provide an impetus for studying OP and OF in CRCS.

Using Medicare Claims to Examine Long-term Prostate Cancer Risk of Finasteride in the Prostate Cancer Prevention Trial.

Background: Investigators have used administrative claims to better understand cancer outcomes when a research question cannot feasibly be examined within a study. The Prostate Cancer Prevention Trial (PCPT) showed that seven years of finasteride reduced prostate cancer (PC) risk by 25% in men age 55 years or older. However, it was unclear whether the observed reduction in PC for finasteride participants would be maintained after finasteride discontinuation. Methods: We examined PC diagnoses identified by PCPT study records and Medicare claims (finasteride = 9423, placebo = 9457). A Medicare-defined PC diagnosis algorithm was defined using diagnosis and procedure codes. Multivariable Cox regression was used to examine time to PC within prespecified follow-up windows (<6.5, 6.5-7.5, and >7.5 years) using time-dependent covariates interacting with intervention assignment to account for the PCPT protocol-specified end-of-study biopsy at seven years. All statistical tests were two-sided. Results: Median follow-up using the linked database was 16 years. Overall, finasteride arm participants had a 21.1% decrease in the hazard ratio of PC (hazard ratio [HR] = 0.79, 95% confidence interval [CI] = 0.74 to 0.84, P < .001). The beneficial effect of finasteride in reducing the hazard ratio of PC was most pronounced in the first 7.5 years (HR = 0.71, 95% CI = 0.66 to 0.77, P < .001), consistent with the original study findings; after 7.5 years, there was no increased risk of PC for finasteride arm participants (HR = 1.10, 95% CI = 0.96 to 1.26, P = .18). Conclusions: Finasteride provides a substantial reduction in PC through 16 years of follow-up. There was no strong evidence that the benefit of finasteride diminished after the end-of-study follow-up. Utilizing Medicare claims to augment PCPT follow-up illustrates how the novel use of secondary data sources can enhance the ability to detect long-term outcomes from prospective studies.

Communication Practices of Mammography Facilities and Timely Follow-up of a Screening Mammogram with a BI-RADS 0 Assessment.

RATIONALE AND OBJECTIVES: The objective of this study was to evaluate the association of communication practices with timely follow-up of screening mammograms read as Breast Imaging Reporting and Data Systems (BI-RADS) 0 in the Population-based Research Optimizing Screening through Personalized Regimens (PROSPR) consortium. MATERIALS AND METHODS: A radiology facility survey was conducted in 2015 with responses linked to screening mammograms obtained in 2011-2014. We considered timely follow-up to be within 15 days of the screening mammogram. Generalized estimating equation models were used to evaluate the association between modes of communication with patients and providers and timely follow-up, adjusting for PROSPR site, patient age, and race and ethnicity. RESULTS: The analysis included 34,680 mammography examinations with a BI-RADS 0 assessment among 28 facilities. Across facilities, 85.6% of examinations had a follow-up within 15 days. Patients in a facility where routine practice was to contact the patient by phone if follow-up imaging was recommended were more likely to have timely follow-up (odds ratio [OR] 4.63, 95% confidence interval [CI] 2.76-7.76), whereas standard use of mail was associated with reduced timely follow-up (OR 0.47, 95% CI 0.30-0.75). Facilities that had standard use of electronic medical records to report the need for follow-up imaging to a provider had less timely follow-up (OR 0.56, 95% CI 0.35-0.90). Facilities that routinely contacted patients by mail if they missed a follow-up imaging visit were more likely to have timely follow-up (OR 1.65, 95% CI 1.02-2.69). CONCLUSIONS: Our findings support the value of telephone communication to patients in relation to timely follow-up. Future research is needed to evaluate the role of communication in completing the breast cancer screening episode.

Diabetes Treatments and Risks of Adverse Breast Cancer Outcomes among Early-Stage Breast Cancer Patients: A SEER-Medicare Analysis.

The widely prescribed diabetes medicine metformin has been reported to lower the risk of incident breast cancer, but it is unclear whether it affects malignant progression after diagnosis. In this study, we conducted a retrospective cohort study using the linked Surveillance, Epidemiology, and End-Results (SEER)-Medicare database. Women were included in the study if they were aged 66 to 80 years, newly diagnosed with stage I or II breast cancer, and enrolled in Medicare Parts A, B, and D during 2007 to 2011. Information on dispensed diabetes-related medications was obtained from Medicare Part D claims data. Our primary outcomes were second breast cancer events (SBCE), breast cancer recurrence, and breast cancer death. Time-varying Cox proportional hazard models were used to estimate HRs and their 95% confidence intervals (CI). Among 14,766 women included in the study, 791 experienced SBCE, 627 had a recurrence, and 237 died from breast cancer. Use of metformin (n = 2,558) was associated with 28% (95% CI, 0.57-0.92), 31% (95% CI, 0.53-0.90), and 49% (95% CI, 0.33-0.78) lower risks of an SBCE, breast cancer recurrence, and breast cancer death. Use of sulfonylureas or insulin was associated with 1.49- (95% CI, 1.00-2.23) and 2.58-fold (95% CI, 1.72-3.90) higher risks of breast cancer death. Further research may be warranted to determine whether metformin is a preferred treatment for diabetes among breast cancer survivors and whether it benefits breast cancer patients without diabetes. Cancer Res; 77(21); 6033-41. ©2017 AACR.

Use of Antihypertensive Medications and Risk of Adverse Breast Cancer Outcomes in a SEER-Medicare Population.

Background: It is unclear if use of common antihypertensive medications influences the risk of adverse breast cancer outcomes.Methods: Using the linked Surveillance, Epidemiology and End-Results (SEER)-Medicare database, we identified 14,766 women between ages 66 and 80 years diagnosed with incident stage I/II breast cancer between 2007 and 2011. Medicare Part D data were obtained to characterize women's post-cancer use of various antihypertensive medications. Outcomes included a second breast cancer event (SBCE; a composite outcome defined as the first of a recurrence or a second contralateral primary breast cancer), breast cancer recurrence, and breast cancer-specific mortality. Time-varying Cox proportional hazard models were used to estimate hazard ratios (HR) and their associated 95% confidence intervals (CI).Results: There were 791 SBCEs, 627 breast cancer recurrences, and 237 breast cancer deaths identified over a median follow-up of 3 years. Use of diuretics (n = 8,517) after breast cancer diagnosis was associated with 29% (95% CI, 1.10-1.51), 36% (95% CI, 1.14-1.63) and 51% (95% CI, 1.11-2.04) higher risks of a SBCE, recurrence, and breast cancer death, respectively. Compared with nonusers, ß-blockers users (n = 7,145) had a 41% (95% CI, 1.07-1.84) higher risk of breast cancer death. Use of angiotensin II receptor blockers, calcium channel blockers and angiotensin-converting enzyme inhibitors were not associated with risks of breast cancer outcomes.Conclusions: Use of diuretics and ß-blockers may be associated with increased risk of breast cancer outcomes among older women.Impact: Most antihypertensive medications are safe with respect to breast cancer outcomes, but more research is needed for diuretics and ß-blockers. Cancer Epidemiol Biomarkers Prev; 26(11); 1603-10. ©2017 AACR.

History of Diabetes and Survival Outcome Among Participants 65 Years or Older in SWOG Clinical Trials.

PURPOSE: Diabetes is common, increases with age, and may affect outcomes among people with cancer. Understanding the association between diabetes and cancer outcome is challenging, because patients with diabetes have increased all-cause mortality compared with patients without diabetes. METHODS: We systematically examined the phase III trial database of SWOG to identify patients enrolled in trials during the period from 1999 to 2011. We linked the SWOG clinical records to Medicare claims data according to Social Security number, sex, and date of birth. Medicare claims were used to identify diabetes with at least 6 months of continuous Medicare coverage immediately before registration. Multivariable Cox regression was used to compare survival outcomes between patients with and without diabetes for each of 10 tumor cohorts. The primary outcome was overall survival. We also examined progression-free survival and cancer-free survival. RESULTS: In total, 6,422 patients from 15 trials were ≥ 65.5 years of age, of whom 3,173 patients (49%) met the criteria for linkage to Medicare claims. Thirty percent (n = 952) had claims for diabetes before registration. Patients with diabetes were more likely to be black ( P < .001), but no other differences in demographic characteristics were observed. In multivariable Cox regression, no association was found between baseline diabetes and overall or progression-free survival; in one case, patients with diabetes had marginally worse cancer-free survival (advanced non-small-cell lung cancer; P = .05). A global test found that baseline diabetes was associated with worse overall survival ( P = .03) across the entire panel of analyses. CONCLUSION: Diabetes is common among elderly patients enrolled in clinical trials. Unlike prior observational studies, among patients treated with uniform treatment regimens, and controlling for known prognostic factors, we did not observe an association between diabetes and progression-free or cancer-free survival.

Long-term Consequences of Finasteride vs Placebo in the Prostate Cancer Prevention Trial.

BACKGROUND: Finasteride has been found to reduce the risk of low-grade prostate cancer but to have no impact on overall survival. The long-term adverse and beneficial consequences of finasteride have not been examined. METHODS: We used a linkage between data from the Prostate Cancer Prevention Trial (PCPT) and Medicare claims. Patients were examined by randomized study arm (finasteride vs placebo for 7 years) for long-term consequences of the intervention, including cardiac, endocrine, and sexual dysfunction, depression, diabetes, and benign prostatic hyperplasia (BPH)-related events. To examine time to events, we used cumulative incidence and Cox regression, adjusting for covariates. All statistical tests were two-sided. RESULTS: A total of 13 935 of 18 880 participants (73.8%) in the PCPT were linked to Medicare claims, with median Medicare follow-up assessment time of 16 years from trial registration. There were no differences between finasteride and placebo participants with respect to important baseline factors or amount of Medicare follow-up assessment time. Finasteride patients had a 10% higher risk of new claims for depression (hazard ratio [HR] = 1.10, 95% confidence interval [CI] = 1.01 to 1.19, P = .04) and a 6% lower risk of procedures for BPH-related events (primarily lower urinary tract symptoms; HR = 0.94, 95% CI = 0.89 to 1.00, P = .03). No other differences were found in rates of long-term consequences of intervention in the two study arms. CONCLUSIONS: Finasteride use is associated with reduced need for procedures for relief of BPH-related events and a modest increase in depression. Overall, there is little need to worry about long-term noncancer consequences of finasteride use in those who use it for treatment of symptomatic BPH, hair growth, or prevention of cancer.

Comorbidities and Risk of Chemotherapy-Induced Peripheral Neuropathy Among Participants 65 Years or Older in Southwest Oncology Group Clinical Trials.

BACKGROUND: Neuropathy is a debilitating toxicity associated with various chemotherapy agents. We evaluated the association between common comorbid conditions and the development of peripheral neuropathy in patients treated with taxane-based chemotherapy. METHODS: We examined the Southwest Oncology Group database to identify phase II and III trials that included taxane therapy from 1999 to 2011. We linked the Southwest Oncology Group clinical records to Medicare claims data according to Social Security number, sex, and date of birth. The following disease conditions potentially associated with peripheral neuropathy were evaluated: diabetes, hypothyroidism, hypercholesterolemia, hypertension, varicella zoster, peripheral vascular disease, and autoimmune diseases. Multivariate logistic regression was used to model the odds of experiencing grade 2 to 4 neuropathy. RESULTS: A total of 1,401 patients from 23 studies were included in the analysis. Patients receiving paclitaxel were more likely to experience grade 2 to 4 neuropathy compared with docetaxel (25% v 12%, respectively; OR, 2.20; 95% CI, 1.52 to 3.18; P < .001). The inclusion of a platinum agent was also associated with greater neuropathy (OR, 1.68; 95% CI, 1.18 to 2.40; P = .004). For each increase in age of 1 year, the odds of neuropathy increased 4% (P = .006). Patients with complications from diabetes had more than twice the odds of having neuropathy (OR, 2.13; 95% CI, 1.31 to 3.46; P = .002) compared with patients with no diabetes. In contrast, patients with autoimmune disease were half as likely to experience neuropathy (OR, 0.49; 95% CI, 0.24 to 1.02; P = .06). The other conditions were not associated with neuropathy. CONCLUSION: We found that in addition to drug-related factors, age and history of diabetes were independent predictors of the development of chemotherapy-induced peripheral neuropathy. Interestingly, we also observed that a history of autoimmune disease was associated with reduced odds of neuropathy. Patients with diabetic complications may choose to avoid paclitaxel or taxane plus platinum combination therapies if other efficacious options exist.

The diffusion of docetaxel in patients with metastatic prostate cancer.

BACKGROUND: Diffusion of new cancer treatments can be both inefficient and incomplete. The uptake of new treatments over time (diffusion) has not been well studied. We analyzed the diffusion of docetaxel in metastatic prostate cancer. METHODS: We identified metastatic prostate cancer patients diagnosed from 1995 to 2007 using the Surveillance, Epidemiology, and End Results Program (SEER)-Medicare database. Medicare claims through 2008 were analyzed. We assessed cumulative incidence of docetaxel by socioeconomic, demographic, and comorbidity variables, and compared diffusion patterns to landmark events including release of phase III results and FDA approval dates. We compared docetaxel diffusion patterns in prostate cancer to those in metastatic breast, lung, ovarian, and gastric cancers. To model docetaxel use over time, we used the classic "mixed influence" deterministic diffusion model. All statistical tests were two-sided. RESULTS: We identified 6561 metastatic prostate cancer patients; 1350 subsequently received chemotherapy. Among patients who received chemotherapy, docetaxel use was 95% by 2008. Docetaxel uptake was statistically significantly slower (P < .01) for patients older than 65 years, blacks, patients in lower income areas, and those who experienced poverty. Eighty percent of docetaxel diffusion occurred prior to the May, 2004 release of phase III results showing superiority of docetaxel over standard-of-care. The maximum increase in the rate of use of docetaxel occurred nearly simultaneously for prostate cancer as for all other cancers combined (in 2000). CONCLUSION: Efforts to increase the diffusion of treatments with proven survival benefits among disadvantaged populations could lead to cancer population survival gains. Docetaxel diffusion mostly preceded phase III evidence for its efficacy in castration-resistant prostate cancer, and appeared to be a cancer-wide-rather than a disease-specific-phenomenon. Diffusion prior to definitive evidence indicates the prevalence of off-label chemotherapy use.

The value of comparative effectiveness research: projected return on investment of the RxPONDER trial (SWOG S1007).

OBJECTIVE: The objective of this study was to assess the value of research of the RxPONDER study, an ongoing comparative effectiveness RCT designed to evaluate a 21-gene profile in early stage, node-positive breast cancer. METHODS: We developed a disease-based decision-analytic model to compare use of the 21-gene profile versus standard care. Key clinical data were derived from SWOG-8814, an RCT of chemotherapy in lymph node-positive breast cancer. Other model parameters were obtained from published sources. Probabilistic simulations and value of information calculations were used to assess the expected value of sample information (EVSI) and the expected value of sample parameter information (EVSPI). RESULTS: The cost of the RxPONDER trial is expected to be at least $27 million. The expected value of research of the RxPONDER trial ranged from $450 million to $1 billion, representing a return of 17 to 39 times the projected cost of the trial. The primary objective of RxPONDER, to assess survival, had the largest estimated value relative to other model inputs. The value of RxPONDER increased by $50 million to $100 million after stakeholder input on additional data collection. CONCLUSION: The RxPONDER study appears to represent a good investment of public research funds. Stakeholder engagement and assessment of the return on investment should be considered to optimize and quantify the value of comparative effectiveness studies.

Evaluating components of dental care utilization among adults with diabetes and matched controls via hurdle models.

BACKGROUND: About one-third of adults with diabetes have severe oral complications. However, limited previous research has investigated dental care utilization associated with diabetes. This project had two purposes: to develop a methodology to estimate dental care utilization using claims data and to use this methodology to compare utilization of dental care between adults with and without diabetes. METHODS: Data included secondary enrollment and demographic data from Washington Dental Service (WDS) and Group Health Cooperative (GH), clinical data from GH, and dental-utilization data from WDS claims during 2002-2006. Dental and medical records from WDS and GH were linked for enrollees continuously and dually insured during the study. We employed hurdle models in a quasi-experimental setting to assess differences between adults with and without diabetes in 5-year cumulative utilization of dental services. Propensity score matching adjusted for differences in baseline covariates between the two groups. RESULTS: We found that adults with diabetes had lower odds of visiting a dentist (OR = 0.74, p < 0.001). Among those with a dental visit, diabetes patients had lower odds of receiving prophylaxis (OR = 0.77), fillings (OR = 0.80) and crowns (OR = 0.84) (p < 0.005 for all) and higher odds of receiving periodontal maintenance (OR = 1.24), non-surgical periodontal procedures (OR = 1.30), extractions (OR = 1.38) and removable prosthetics (OR = 1.36) (p < 0.001 for all). CONCLUSIONS: Patients with diabetes are less likely to use dental services. Those who do are less likely to use preventive care and more likely to receive periodontal care and tooth-extractions. Future research should address the possible effectiveness of additional prevention in reducing subsequent severe oral disease in patients with diabetes.

Effectiveness of computer-aided detection in community mammography practice.

BACKGROUND: Computer-aided detection (CAD) is applied during screening mammography for millions of US women annually, although it is uncertain whether CAD improves breast cancer detection when used by community radiologists. METHODS: We investigated the association between CAD use during film-screen screening mammography and specificity, sensitivity, positive predictive value, cancer detection rates, and prognostic characteristics of breast cancers (stage, size, and node involvement). Records from 684 956 women who received more than 1.6 million film-screen mammograms at Breast Cancer Surveillance Consortium facilities in seven states in the United States from 1998 to 2006 were analyzed. We used random-effects logistic regression to estimate associations between CAD and specificity (true-negative examinations among women without breast cancer), sensitivity (true-positive examinations among women with breast cancer diagnosed within 1 year of mammography), and positive predictive value (breast cancer diagnosed after positive mammograms) while adjusting for mammography registry, patient age, time since previous mammography, breast density, use of hormone replacement therapy, and year of examination (1998-2002 vs 2003-2006). All statistical tests were two-sided. RESULTS: Of 90 total facilities, 25 (27.8%) adopted CAD and used it for an average of 27.5 study months. In adjusted analyses, CAD use was associated with statistically significantly lower specificity (OR = 0.87, 95% confidence interval [CI] = 0.85 to 0.89, P < .001) and positive predictive value (OR = 0.89, 95% CI = 0.80 to 0.99, P = .03). A non-statistically significant increase in overall sensitivity with CAD (OR = 1.06, 95% CI = 0.84 to 1.33, P = .62) was attributed to increased sensitivity for ductal carcinoma in situ (OR = 1.55, 95% CI = 0.83 to 2.91; P = .17), although sensitivity for invasive cancer was similar with or without CAD (OR = 0.96, 95% CI = 0.75 to 1.24; P = .77). CAD was not associated with higher breast cancer detection rates or more favorable stage, size, or lymph node status of invasive breast cancer. CONCLUSION: CAD use during film-screen screening mammography in the United States is associated with decreased specificity but not with improvement in the detection rate or prognostic characteristics of invasive breast cancer.

Multiplexed assessment of the Southwest Oncology Group-directed Intergroup Breast Cancer Trial S9313 by AQUA shows that both high and low levels of HER2 are associated with poor outcome.

Assessment of key breast cancer tissue biomarkers is often done using nonquantitative methods. We hypothesized that use of continuous analysis of expression with the AQUA method of automated quantitative analysis will provide prognostic information beyond that attainable with conventional methods. A tissue microarray was made from 2123 of 3122 patients accrued to SWOG 9313, in which sequential doxorubicin (A) and cyclophosphamide (C) was compared with combination AC and in which all patients except premenopausal estrogen receptor (ER)-negative patients received tamoxifen. Multiplexed assays of 1) HER2 and estrogen receptor and 2) progesterone receptor (PgR) and p53 were performed on the two slides using the immunofluorescence-based AQUA method of automated quantitative analysis. Both ER and PgR showed unimodal distributions and significantly predicted disease-free survival when tested as continuous variables and adjusted for node status, tumor size, treatment, and menopausal status (P = 0.005 and P < 0.001, respectively). HER2, measured as a continuous variable, showed a biphasic effect on disease-free survival. Both high and low expressers of HER2 have worse outcomes (when low levels are equivalent to that seen in normal breast ducts). In patients who were uniformly treated with AC chemotherapy and tamoxifen (when indicated), both ER and PgR, assessed as continuous variables, were highly prognostic, whereas p53 expression was not. This assay method may provide a new companion diagnostic approach for targeted therapies.

Overview of methods to estimate the medical costs of cancer.

BACKGROUND: Methods to estimate the direct medical costs of cancer care have evolved into several commonly used methods. OBJECTIVES: We describe the different estimation techniques briefly to contrast these approaches and provide a framework for other articles in this monograph. MEASURES AND RESULTS: One can estimate costs for all individuals with a specific cancer in a fixed calendar period (prevalent costs) or describe costs starting at the point of diagnosis and estimate immediate and long-term costs (incident costs). A variant of the incidence approach is to divide cancer care into initial, continuing, and terminal care phases and apply these phase-specific cost estimates to survival probabilities. The additional burden because of the cancer may be computed using cancer services (attributable costs) or by subtracting costs of healthy matched individuals (net costs). CONCLUSIONS: The strengths and weaknesses of these approaches are illustrated to show that the most appropriate choice will depend on whether the goal is to plan for health care costs, set public policy, or assess impact of potential interventions.

Treatment quality and outcomes of African American versus white breast cancer patients: retrospective analysis of Southwest Oncology studies S8814/S8897.

PURPOSE: Women of African ancestry (AA) have lower WBC counts and are more likely to have treatment delays and discontinue adjuvant breast cancer therapy early compared with white women. We assessed the association between race and treatment discontinuation/delay, WBC counts, and survival in women enrolled onto breast cancer clinical trials. PATIENTS AND METHODS: AA and white women from Southwest Oncology Group adjuvant breast cancer trials (S8814/S8897) were matched by age and protocol. Only the treatment arms in which patients were scheduled to receive six cycles of chemotherapy were analyzed. RESULTS: A total of 317 pairs of patients (n = 634) were analyzed. At baseline, AA women had higher body-surface area (P < .0001) and lower WBC (P = .0009). AA women were more likely to have tumors that were > or = 2 cm (P = .01) and hormone receptor negative (P < .0001). AA women, versus white women, were marginally more likely to discontinue treatment early (11% v 7%, respectively; P = .07) or have one or more treatment delays (85% v 79%, respectively; P = .07) and were significantly more likely to experience the combined end point (discontinuation/delay; 87% v 81%, respectively; P = .04). The mean relative dose-intensity (RDI) was similar for both groups (87% in AA women v 86% in white women); however, overall, 43% had an RDI of less than 85%. After adjusting for baseline WBC and prognostic factors in a multivariate model, AA women had worse disease-free survival (hazard ratio [HR] = 1.56; 95% CI, 1.15 to 2.11; P = .005) and overall survival (HR = 1.95; 95% CI, 1.36 to 2.78; P = .0002). The inclusion of RDI and treatment delivery/quality in the regression had little impact on the results. CONCLUSION: On cooperative group breast cancer trials, AA and white women had similar RDIs, but AA women were more likely to experience early discontinuation or treatment delay. Despite correcting for these factors and known predictors of outcome, AA women still had worse survival.