The Association of Rural Residence With Surgery and Adjuvant Radiation in Medicare Beneficiaries With Rectal Cancer

Purpose

Radiation therapy and surgery are fundamental site-directed therapies for nonmetastatic rectal cancer. To understand the relationship between rurality and access to specialized care, we characterized the association of rural patient residence with receipt of surgery and radiation therapy among Medicare beneficiaries with rectal cancer.

Methods and Materials

We identified fee-for-service Medicare beneficiaries aged 65 years or older diagnosed with nonmetastatic rectal cancer from 2016 to 2018. Beneficiary place of residence was assigned to one of 3 geographic categories (metropolitan, micropolitan, or small town/rural) based on census tract and corresponding rural urban commuting area codes. Multivariable regression models were used to determine associations between levels of rurality and receipt of both radiation and proctectomy within 180 days of diagnosis. In addition, we explored associations between patient rurality and characteristics of surgery and radiation such as minimally invasive surgery (MIS) or intensity modulated radiation therapy (IMRT).

Results

Among 13,454 Medicare beneficiaries with nonmetastatic rectal cancer, 3926 (29.2%) underwent proctectomy within 180 days of being diagnosed with rectal cancer, and 1792 (13.3%) received both radiation and proctectomy. Small town/rural residence was associated with an increased likelihood of receiving both radiation and proctectomy within 180 days of diagnosis (adjusted subhazard ratio, 1.15; 95% CI, 1.02-1.30). Furthermore, small town/rural radiation patients were significantly less likely to receive IMRT (adjusted odds ratio, 0.62; 95% CI, 0.48-0.80) or MIS (adjusted odds ratio, 0.80; 95% CI, 0.66-0.97) than metropolitan patients.

Conclusions

Although small town/rural Medicare beneficiaries were overall more likely to receive both radiation and proctectomy for their rectal cancer, they were less likely to receive preoperative IMRT or MIS as part of their treatment regimen. Together, these findings clarify that among Medicare beneficiaries, there appeared to be a similar utilization of radiation resources and time to radiation treatment regardless of rural/urban status.

A Survey of Cancer Risk Behaviors, Beliefs, and Social Drivers of Health in New Hampshire and Vermont

Compared with urban areas, rural areas have higher cancer mortality and have experienced substantially smaller declines in cancer incidence in recent years. In a New Hampshire (NH) and Vermont (VT) survey, we explored the roles of rurality and educational attainment on cancer risk behaviors, beliefs, and other social drivers of health. In February-March 2022, two survey panels in NH and VT were sent an online questionnaire. Responses were analyzed by rurality and educational attainment. Respondents (N = 1,717, 22%) mostly lived in rural areas (55%); 45% of rural and 25% of urban residents had high school education or less and this difference was statistically significant. After adjustment for rurality, lower educational attainment was associated with smoking, difficulty paying for basic necessities, greater financial difficulty during the COVID-19 pandemic, struggling to pay for gas (P < 0.01), fatalistic attitudes toward cancer prevention, and susceptibility to information overload about cancer prevention. Among the 33% of respondents who delayed getting medical care in the past year, this was more often due to lack of transportation in those with lower educational attainment (21% vs. 3%, P = 0.02 adjusted for rurality) and more often due to concerns about catching COVID-19 among urban than rural residents (52% vs. 21%; P < 0.001 adjusted for education). In conclusion, in NH/VT, smoking, financial hardship, and beliefs about cancer prevention are independently associated with lower educational attainment but not rural residence. These findings have implications for the design of interventions to address cancer risk in rural areas.

Significance

In NH and VT, the finding that some associations between cancer risk factors and rural residence are more closely tied to educational attainment than rurality suggest that the design of interventions to address cancer risk should take educational attainment into account.

Cancer Epidemiology in the Northeastern United States (2013-2017)

We tested the hypotheses that adult cancer incidence and mortality in the Northeast region and in Northern New England (NNE) were different than the rest of the United States, and described other related cancer metrics and risk factor prevalence. Using national, publicly available cancer registry data, we compared cancer incidence and mortality in the Northeast region with the United States and NNE with the United States overall and by race/ethnicity, using age-standardized cancer incidence and rate ratios (RR). Compared with the United States, age-adjusted cancer incidence in adults of all races combined was higher in the Northeast (RR, 1.07; 95% confidence interval [CI] 1.07-1.08) and in NNE (RR 1.06; CI 1.05-1.07). However compared with the United States, mortality was lower in the Northeast (RR, 0.98; CI 0.98-0.98) but higher in NNE (RR, 1.05; CI 1.03-1.06). Mortality in NNE was higher than the United States for cancers of the brain (RR, 1.16; CI 1.07-1.26), uterus (RR, 1.32; CI 1.14-1.52), esophagus (RR, 1.36; CI 1.26-1.47), lung (RR, 1.12; CI 1.09-1.15), bladder (RR, 1.23; CI 1.14-1.33), and melanoma (RR, 1.13; CI 1.01-1.27). Significantly higher overall cancer incidence was seen in the Northeast than the United States in all race/ethnicity subgroups except Native American/Alaska Natives (RR, 0.68; CI 0.64-0.72). In conclusion, NNE has higher cancer incidence and mortality than the United States, a pattern that contrasts with the Northeast region, which has lower cancer mortality overall than the United States despite higher incidence.

Significance

These findings highlight the need to identify the causes of higher cancer incidence in the Northeast and the excess cancer mortality in NNE.

Association of rurality with utilization of palliative care and hospice among Medicare beneficiaries who died from pancreatic cancer: A cohort study

BACKGROUND

Pancreatic cancer has a 5-year survival of just 10%. Services such as palliative care and hospice are thus crucial in this population, yet their geographic accessibility and utilization remains unknown.

AIM

We studied the association between rurality of patient residence and the use of palliative care and hospice.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study of continuously enrolled fee-for-service Medicare beneficiaries aged ≥65 diagnosed with incident pancreatic cancer between 04/01/2016-08/31/2018 and who died by 12/31/2018.

RESULTS

In this decedent cohort of 31,460 patients, 77% lived in metropolitan areas, 11% in micropolitan areas, 7% in small towns, and 5% in rural areas. Patient demographics were largely similar across rurality; however, the proportion of White, non-Hispanic patients and social deprivation was highest in rural areas and lowest in metropolitan areas. Overall, 33% of patients used any palliative care and 77% received hospice services. After risk adjustment, there were no statistically significant differences in the use of palliative care for patients residing in metropolitan versus micropolitan, small town, or rural areas. Patients in small town (OR = 0.77, 95% CI: 0.69-0.86) and rural areas (OR = 0.75, 95% CI: 0.66-0.85) had lower adjusted odds of receiving hospice care compared to patients in metropolitan areas.

CONCLUSIONS

The use of palliative care services captured in Medicare was low, representing either underutilization or failure to accurately measure the extent of services used. While the overall level of hospice enrollment was high, patients in rural communities had relatively lower use of hospice services compared to those in metropolitan areas.

Comparison of Oncologist and Model Estimates of Risk for Hospitalization During Systemic Therapy for Advanced Cancer

PURPOSE

A validated risk model with inputs of pretreatment sodium and albumin can identify patients at risk for hospitalization during cancer treatment. We evaluated how the model compares with risk estimates from treating oncologists.

METHODS

We evaluated the 30-day risk of hospitalization or death in patients starting palliative-intent systemic therapy for solid tumor malignancy. For each patient, we prospectively recorded categorical estimates of 30-day hospitalization risk (bottom third, middle third, top third) generated by a treating oncologist and by the two-variable model; a third hybrid risk estimate represented a composite of the oncologist and model risk assessments. We analyzed the agreement of oncologist and model-based risk estimates and compared discrimination, sensitivity, and specificity of each risk assessment method.

RESULTS

We collected oncologist, model, and hybrid estimates of hospitalization risk for 120 patients. The 30-day rate of hospitalization or death was 20%. There was minimal agreement between oncologist and model risk estimates (weighted kappa = 0.27). The c-statistic (a measure of discrimination) was 0.69 (95% CI, 0.57 to 0.81) for the clinician assessment, 0.77 for the model assessment (CI, 0.67 to 0.86; P = .24 compared with the oncologist assessment), and 0.79 for the hybrid assessment (CI, 0.69 to 0.90; P = .007 compared with the oncologist assessment). Sensitivity and specificity of the high-risk categorization did not differ significantly between the oncologist and model assessments; the hybrid assessment was significantly more sensitive (P = .02) and less specific (P = .03) than the oncologist assessment.

CONCLUSION

A model with inputs of pretreatment sodium and albumin improves oncologists' predictions of hospitalization risk during cancer treatment.

Women's Breast Cancer Screening Confidence by Screening Modality and Breast Density: A Breast Cancer Surveillance Consortium Survey Study

Objective: Little is known about women's confidence in their breast cancer screening. We sought to characterize breast cancer screening confidence by imaging modality and clinically assessed breast density. Materials and Methods: We undertook a cross-sectional survey of women ages 40-74 years who received digital mammography (DM), digital breast tomosynthesis (DBT), and/or breast magnetic resonance imaging (MRI) with a normal screening exam in the prior year. The main outcome was women's confidence (Very, Somewhat, A little, Not at all) in their breast cancer screening detecting any cancer. Multivariable logistic regression identified correlates of being very confident in breast cancer screening by screening modality group: Group 1) DM vs. DBT and Group 2) DM or DBT alone vs. with supplemental MRI. Results: Overall, 2329 of 7439 (31.3%) invitees participated, with 30%-61% being very confident in their screening across modality and density subgroups. Having dense versus nondense breasts was associated with lower odds of being very confident (Group 1: odds ratio [OR]: 0.58; 95% confidence interval [CI]: 0.46-0.79; Group 2: OR: 0.56; 95% CI: 0.40-0.79). There were no differences by modality within Group 1, but for Group 2, women undergoing MRI had higher odds of being very confident (OR: 1.69; 95% CI: 1.21-2.37). Other correlates of greater screening confidence were as follows: Group 1-being offered a screening test choice and cost not influencing modality received, and Group 2-decision satisfaction and worry. Conclusions: Women with dense breasts had lower screening confidence regardless of screening modality and those undergoing MRI had higher confidence regardless of density. The importance of informing women about screening options is underscored by observed associations between screening choice, decision satisfaction, and screening confidence. ClinicalTrials.gov: NCT02980848.

Factors Influencing Telemedicine Use at a Northern New England Cancer Center During the COVID-19 Pandemic

PURPOSE

To characterize the use of telemedicine for oncology care over the course of the COVID-19 pandemic in Northern New England with a focus on factors affecting trends.

METHODS

We performed a retrospective observational study using patient visit data from electronic health records from hematology-oncology and radiation-oncology service lines spanning the local onset of the pandemic from March 18, 2020, through March 31, 2021. This period was subdivided into four phases designated as lockdown, transition, stabilization, and second wave. Generalized linear mixed regression models were used to estimate the effects of patient characteristics on trends for rates of telemedicine use across phases and the effects of visit type on patient satisfaction and postvisit ER or hospital admissions within 2 weeks.

RESULTS

A total of 19,280 patients with 102,349 visits (13.1% audio-only and 1.4% video) were studied. Patient age (increased use in age < 45 and 85 years and older) and urban residence were associated with higher use of telemedicine, especially after initial lockdown. Recent cancer therapy, ER use, and hospital admissions in the past year were all associated with lower telemedicine utilization across pandemic phases. Provider clinical department corresponded to the largest differences in telemedicine use across all phases. ER and hospital admission rates in the 2 weeks after a telehealth visit were lower than those in in-person visits (0.7% v 1.3% and 1.2% v 2.7% for ER and hospital use, respectively; P < .001). Patient satisfaction did not vary across visit types.

CONCLUSION

Telemedicine use in oncology during the COVID-19 pandemic varied according to the phase and patient, medical, and health system factors, suggesting opportunities for standardization of care and need for attention to equitable telemedicine access.

Breast cancer screening for carriers of ATM, CHEK2, and PALB2 pathogenic variants: A comparative modeling analysis

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Background: Inherited pathogenic variants in ATM, CHEK2, and PALB2 confer moderate to high risks of breast cancer. The optimal approach to screening in these women has not been established. Methods: We used two simulation models from the Cancer Intervention and Surveillance Modeling Network (CISNET) and data from the Cancer Risk Estimates Related to Susceptibility consortium (CARRIERS) to project lifetime breast cancer incidence and mortality in ATM, CHEK2, and PALB2 carriers. We simulated screening with annual mammography from ages 40-74 alone and with annual magnetic resonance imaging (MRI) starting at ages 40, 35, 30, and 25. Joint and separate mammography and MRI screening performance was based on published literature. Lifetime outcomes per 1,000 women were reported as means and ranges across both models. Results: Estimated risk of breast cancer by age 80 was 22% (21-23%) for ATM, 28% (26-30%) for CHEK2, and 40% (38-42%) for PALB2. Screening with MRI and mammography reduced breast cancer mortality by 52-60% across variants (Table). Compared to no screening, starting MRI at age 30 increased life years (LY)/1000 women by 501 (478-523) in ATM, 620 (587-652) in CHEK2, and 1,025 (998-1,051) in PALB2. Starting MRI at age 25 versus 30 gained 9-12 LY/1000 women with 517-518 additional false positive screens and 197-198 benign biopsies. Conclusions: For women with ATM, CHEK2, and PALB2 pathogenic variants, breast cancer screening with MRI and mammography halves breast cancer mortality. These mortality benefits are similar to those for MRI screening for BRCA1/2 mutation carriers and should inform practice guidelines.[Table: see text]

Impact of disruptions in breast cancer control due to the COVID-19 pandemic on breast cancer mortality in the United States: Estimates from collaborative simulation modeling

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Background: The COVID-19 pandemic has disrupted breast cancer control through short-term declines in screening, delays in diagnosis and reduced/delayed treatments. We projected the impact of COVID-19 on future breast cancer mortality.Methods: Three established Cancer Intervention and Surveillance Modeling Network (CISNET) models projected the impact of pandemic-related care disruptions on breast cancer mortality between 2020 and 2030 vs. pre-pandemic care patterns. Based on Breast Cancer Surveillance Consortium data, we modeled reductions in mammography screening utilization, delays in symptomatic cancer diagnosis, and reduced use of chemotherapy for women with early-stage disease for the first six months of the pandemic with return to pre-pandemic patterns after that time. Sensitivity analyses were performed to determine the effect of key model parameters, including the duration of the pandemic impact. Results: By 2030, the models project 1,297 (model range: 1,054-1,900) cumulative excess deaths related to reduced screening; 1,325 (range: 266-2,628) deaths from delayed diagnosis of symptomatic women, and 207 (range: 146-301) deaths from reduced chemotherapy use for early-stage cancer. Overall, the models predict 2,487 (range 1,713-4,875) excess deaths, representing a 0.56% (range: 0.36%-0.99%) cumulative increase over deaths that would be expected by 2030 in the absence of the pandemic’s disruptions. Sensitivity analyses indicated that the impact on mortality would approximately double if the disruptions lasted for a 12-month period. Conclusions: The impact of the initial pandemic-related disruptions in breast cancer care will have a small long-term cumulative impact on breast cancer mortality. The impact of the initial pandemic-related disruptions on breast cancer mortality will largely be mitigated by the rapid return to usual care. As the pandemic continues it will be important to monitor trends in care and reassess the mortality impact.[Table: see text]

Cost effectiveness of DPYD genotyping to screen for dihydropyrimidine dehydrogenase (DPD) deficiency prior to adjuvant chemotherapy for colon cancer

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Background: Fluoropyrimidine chemotherapy agents, including 5-fluorouracil and capecitabine, are the backbone of adjuvant treatment for colon cancer, and adjuvant chemotherapy substantially reduces recurrence and mortality after surgical resection of stage 3 colon cancer. While fluoropyrimidine chemotherapy is generally safe, the risk of severe, potentially fatal chemotherapy toxicity is substantially increased for the 2-3% of U.S. patients with DPD deficiency caused by pathogenic variants in the DPYD gene. DPYD genotype testing is readily available in the U.S. but has not been widely adopted. We evaluated the cost effectiveness of DPYD genotyping prior to adjuvant chemotherapy for colon cancer in the U.S. Methods: We constructed a Markov model to simulate screening for DPD deficiency with DPYD genotyping (versus no screening) among patients receiving fluoropyrimidine-based adjuvant chemotherapy for stage 3 colon cancer. Screen-positive patients were modeled to receive dose-reduced fluoropyrimidine chemotherapy. Model transition probabilities for treatment-related toxicities were derived from published clinical trial data with annotation of DPYD genotype and chemotherapy dosing strategy. Our analysis is from the healthcare perspective, with a time horizon of five years and an annual discount rate of 3% for future costs and benefits. Direct healthcare costs and health utilities were estimated from published sources and converted to 2020 US dollars, and post-treatment survival was modeled from SEER data. The primary outcome was the incremental cost-effectiveness ratio (ICER), defined as dollars per quality-adjusted life year (QALY). We used a value of $100,000/QALY as the cost-effectiveness threshold. One-way sensitivity analyses were used to examine model uncertainty. Results: Compared with no screening, screening for DPD deficiency with DPYD genotyping increased per-patient costs by $106 and improved quality-adjusted survival by 0.0028 QALYs, leading to an ICER of $37,300/QALY. In one-way sensitivity analyses, the ICER exceeded $100,000/QALY when the carrier frequency of pathogenic DPYD gene variants was less than 1.17%, and when the specificity of DPYD genotyping was less than 98.9%. Cost-effectiveness estimates were not sensitive to the cost of DPYD genotyping, the cost of toxicity-related hospitalizations, or the health utility associated with grade 3-4 toxicity. Conclusions: Among patients receiving adjuvant chemotherapy for stage 3 colon cancer, screening for DPD deficiency with DPYD genotyping is a cost-effective strategy for preventing infrequent but severe, sometimes fatal toxicities of fluoropyrimidine chemotherapy.

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.

Cost-effectiveness of spinal manipulative therapy, supervised exercise, and home exercise for older adults with chronic neck pain

BACKGROUND CONTEXT

Chronic neck pain is a prevalent and disabling condition among older adults. Despite the large burden of neck pain, little is known regarding the cost-effectiveness of commonly used treatments.

PURPOSE

This study aimed to estimate the cost-effectiveness of home exercise and advice (HEA), spinal manipulative therapy (SMT) plus HEA, and supervised rehabilitative exercise (SRE) plus HEA.

STUDY DESIGN/SETTING

Cost-effectiveness analysis conducted alongside a randomized clinical trial (RCT) was performed.

PATIENT SAMPLE

A total of 241 older adults (≥65 years) with chronic mechanical neck pain comprised the patient sample.

OUTCOME MEASURES

The outcome measures were direct and indirect costs, neck pain, neck disability, SF-6D-derived quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) over a 1-year time horizon.

METHODS

This work was supported by grants from the National Center for Complementary and Integrative Health (#F32AT007507), National Institute of Arthritis and Musculoskeletal and Skin Diseases (#P60AR062799), and Health Resources and Services Administration (#R18HP01425). The RCT is registered at ClinicalTrials.gov (#NCT00269308). A societal perspective was adopted for the primary analysis. A healthcare perspective was adopted as a sensitivity analysis. Cost-effectivenesswas a secondary aim of the RCT which was not powered for differences in costs or QALYs. Differences in costs and clinical outcomes were estimated using generalized estimating equations and linear mixed models, respectively. Cost-effectiveness acceptability curves were calculated to assess the uncertainty surrounding cost-effectiveness estimates.

RESULTS

Total costs for SMT+HEA were 5% lower than HEA (mean difference: -$111; 95% confidence interval [CI] -$1,354 to $899) and 47% lower than SRE+HEA (mean difference: -$1,932; 95% CI -$2,796 to -$1,097). SMT+HEA also resulted in a greater reduction of neck pain over the year relative to HEA (0.57; 95% CI 0.23 to 0.92) and SRE+HEA (0.41; 95% CI 0.05 to 0.76). Differences in disability and QALYs favored SMT+HEA. The probability that adding SMT to HEA is cost-effective at willingness to pay thresholds of $50,000 to $200,000 per QALY gained ranges from 0.75 to 0.81. If adopting a health-care perspective, costs for SMT+HEA were 66% higher than HEA (mean difference: $515; 95% CI $225 to $1,094), resulting in an ICER of $55,975 per QALY gained.

CONCLUSION

On average, SMT+HEA resulted in better clinical outcomes and lower total societal costs relative to SRE+HEA and HEA alone, with a 0.75 to 0.81 probability of cost-effectiveness for willingness to pay thresholds of $50,000 to $200,000 per QALY.

Developing a Registry for Thyroid Incidentalomas: Lessons Learned and the Path Forward

BACKGROUND

Incidentalomas are findings on an imaging test done for other reasons, for which there are no matching symptoms in the patient. They are common in the adrenal gland, pancreas, liver, and thyroid, among other sites. Incidentalomas are a problem because we have a limited understanding of their natural history: it is difficult to know how much of a threat they pose to individual patients. An observational registry that would allow a systematic study of thyroid incidentalomas could reveal their natural history and the effect of detection on patients' lives, as well as document the cost to the healthcare system. A registry would help to determine which incidentalomas could be monitored and which require action.

STUDY DESIGN

A cohort study was conducted, with case identification via radiology imaging reports with follow-up through a minimum of one year post-identification.

RESULTS

In one year, >109,000 imaging studies were performed that might reveal an incidental thyroid finding (computed tomography scans of the neck or chest, magnetic resonance imaging of the neck, plain x-ray of the chest, non-thyroid directed ultrasound of the neck, positron emission tomography scan, or myocardial perfusion scan). A total of 125 patients were identified as having a thyroid nodule, with a <1% reporting rate among eligible imaging studies, much lower than other published estimates of incidental thyroid nodule prevalence on imaging. Of the 125 nodules, 46 had been previously identified (were not "new"). Of the 79 patients with new nodules, more than half (44; 53%) were not notified of the finding. The approved study design allowed contact only with those who had been clearly notified of their thyroid nodule. Among those who could be reached, many did not recall the finding (6/15; 40%). Of those who did recall the finding, none self-identified it as an incidentaloma.

CONCLUSIONS

There are serious logistical and ethical hurdles to developing observational registries of incidentalomas, as well as threats to data validity because incidentalomas are incompletely identified, reported, and acted upon. Solutions commonly used to optimize data quality for registries would increase reporting, but could potentially overwhelm the healthcare system and harm patients. A novel interventional design that is proposed here for future work may facilitate both study and amelioration of the problem.

How Have Breast Cancer Screening Intervals Changed Since the 2009 USPSTF Guideline Update?

Background: Beginning in 2009, the U.S. Preventives Services Task Force (USPSTF) breast cancer screening guidelines recommended biennial mammography screening for women aged 50–74 years, and shared-decision making for women aged 40–49 years. We evaluated changes in screening interval after release of the 2009 recommendations. Methods: We compared screening intervals over the period between 2006 and 2012, expecting that the screening interval would lengthen over this time period, using data from the Breast Cancer Surveillance Consortium on 909,972 screening mammograms among 351,271 women aged 40–89 years. We stratified intervals based on whether the exam at the end of the interval occurred before or after the 2009 USPSTF decision. Differences in mean interval length by woman-level characteristics were compared using linear regression. Results: Contrary to expectations, the mean interval length (in months) minimally decreased after the 2009 USPSTF guideline compared to prior. Among women aged 40–49 years, the mean interval length decreased from 17.3 months to 17.1 months (difference −0.16, 95% confidence interval [CI] -0.30 to -0.01). Similar small reductions were seen for most age groups. The largest decreases in interval length in the post-USPSTF period were observed among women with a first-degree family history of breast cancer (difference −0.68, 95% CI, −0.82–−0.54) or a 5-year breast cancer risk ≥ 2.5% (difference −0.58, 95% CI, −0.73–−0.44). Conclusions: The 2009 USPSTF guideline update did not lengthen the average mammography screening interval among women routinely participating in mammography screening. Future studies should evaluate whether breast cancer screening intervals lengthen towards biennial intervals following new national 2015 breast cancer screening recommendations, particularly among women under 50 years.

Collaborative Modeling of the Benefits and Harms Associated With Different U.S. Breast Cancer Screening Strategies

BACKGROUND

Controversy persists about optimal mammography screening strategies.

OBJECTIVE

To evaluate screening outcomes, taking into account advances in mammography and treatment of breast cancer.

DESIGN

Collaboration of 6 simulation models using national data on incidence, digital mammography performance, treatment effects, and other-cause mortality.

SETTING

United States.

PATIENTS

Average-risk U.S. female population and subgroups with varying risk, breast density, or comorbidity.

INTERVENTION

Eight strategies differing by age at which screening starts (40, 45, or 50 years) and screening interval (annual, biennial, and hybrid [annual for women in their 40s and biennial thereafter]). All strategies assumed 100% adherence and stopped at age 74 years.

MEASUREMENTS

Benefits (breast cancer-specific mortality reduction, breast cancer deaths averted, life-years, and quality-adjusted life-years); number of mammograms used; harms (false-positive results, benign biopsies, and overdiagnosis); and ratios of harms (or use) and benefits (efficiency) per 1000 screens.

RESULTS

Biennial strategies were consistently the most efficient for average-risk women. Biennial screening from age 50 to 74 years avoided a median of 7 breast cancer deaths versus no screening; annual screening from age 40 to 74 years avoided an additional 3 deaths, but yielded 1988 more false-positive results and 11 more overdiagnoses per 1000 women screened. Annual screening from age 50 to 74 years was inefficient (similar benefits, but more harms than other strategies). For groups with a 2- to 4-fold increased risk, annual screening from age 40 years had similar harms and benefits as screening average-risk women biennially from 50 to 74 years. For groups with moderate or severe comorbidity, screening could stop at age 66 to 68 years.

LIMITATION

Other imaging technologies, polygenic risk, and nonadherence were not considered.

CONCLUSION

Biennial screening for breast cancer is efficient for average-risk populations. Decisions about starting ages and intervals will depend on population characteristics and the decision makers' weight given to the harms and benefits of screening.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Factors Associated with Preoperative Magnetic Resonance Imaging Use among Medicare Beneficiaries with Nonmetastatic Breast Cancer

Preoperative breast magnetic resonance imaging (MRI) use among Medicare beneficiaries with breast cancer has substantially increased from 2005 to 2009. We sought to identify factors associated with preoperative breast MRI use among women diagnosed with ductal carcinoma in situ (DCIS) or stage I-III invasive breast cancer (IBC). Using Surveillance, Epidemiology, and End Results and Medicare data from 2005 to 2009 we identified women ages 66 and older with DCIS or stage I-III IBC who underwent breast-conserving surgery or mastectomy. We compared preoperative breast MRI use by patient, tumor and hospital characteristics stratified by DCIS and IBC using multivariable logistic regression. From 2005 to 2009, preoperative breast MRI use increased from 5.9% to 22.4% of women diagnosed with DCIS and 7.0% to 24.3% of women diagnosed with IBC. Preoperative breast MRI use was more common among women who were younger, married, lived in higher median income zip codes and had no comorbidities. Among women with IBC, those with lobular disease, smaller tumors (<1 cm) and those with estrogen receptor negative tumors were more likely to receive preoperative breast MRI. Women with DCIS were more likely to receive preoperative MRI if tumors were larger (>2 cm). The likelihood of receiving preoperative breast MRI is similar for women diagnosed with DCIS and IBC. Use of MRI is more common in women with IBC for tumors that are lobular and smaller while for DCIS MRI is used for evaluation of larger lesions.

Modelling mammography screening for breast cancer in the Canadian context: Modification and testing of a microsimulation model

BACKGROUND

Modelling is a flexible and efficient approach to gaining insight into the trade-offs surrounding a complex process like breast screening, which involves more variables than can be controlled in an experimental study.

DATA AND METHODS

The University of Wisconsin Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer microsimulation model was adapted to simulate breast cancer incidence and screening performance in Canada. The model considered effects of breast density on the sensitivity and specificity of screening. The model's ability to predict age-specific incidence of breast cancer was assessed.

RESULTS

Predictions of age-adjusted incidence over calendar years and age-specific incidence of breast cancer in Canadian women are presented. Based on standard screening strategies, ratios of in situ to invasive disease and stage distribution of disease at diagnosis are compared with data from the British Columbia provincial screening program.

INTERPRETATION

The adapted model performs well in predicting age-specific incidence and cross-sectional incidence in the absence of screening. The ratios of detection of in situ to invasive cancers and the overall stage distribution of detected cancers are in reasonable agreement with empirical data from British Columbia.

Clinical outcomes of modelling mammography screening strategies

BACKGROUND

A validated breast cancer model can be used to compare health outcomes associated with different screening strategies.

DATA AND METHODS

The University of Wisconsin Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer microsimulation model was adapted to simulate breast cancer incidence, screening performance and delivery of optimal therapies in Canada. The model considered effects of breast density on incidence and screening performance. Model predictions of incidence, mortality and life-years (LY) gained for a 1960 birth cohort of women for No Screening were compared with 11 digital mammography screening strategies that varied by starting and stopping age and frequency.

RESULTS

In the absence of screening, the estimate of LYs lost from breast cancer was 360.1 per 1,000 women, and each woman diagnosed with breast cancer after age 40 who dies of breast cancer would lose an average of 19.1 years. Biennial screening at ages 50 to 74 resulted in 116.3 LYs saved. Annual screening at ages 40 to 49, followed by biennial screening to age 74, resulted in 170.3 LY saved. Screening annually at ages 40 to 74 recovered the most: 214 LY saved. Annual screening at age 40 resulted in 54 LY gained per 1,000 women. More frequent screening was associated with an increased ratio of detection of ductal in situ to invasive cancers, more abnormal recalls and more negative biopsies, but a reduction in the number of women required to be screened per life saved or per LY saved.

INTERPRETATION

In general, mortality reduction was found to be associated with the total number of lifetime screens for breast cancer. However, for the same number of screens, more frequent screening after age 50 appeared to have a greater impact than beginning screening earlier. When the number of LYs saved by screening was considered, a greater impact was achieved by screening women in their 40s than by reducing the interval between screens.

Identifying women with dense breasts at high risk for interval cancer: a cohort study

BACKGROUND

Twenty-one states have laws requiring that women be notified if they have dense breasts and that they be advised to discuss supplemental imaging with their provider.

OBJECTIVE

To better direct discussions of supplemental imaging by determining which combinations of breast cancer risk and Breast Imaging Reporting and Data System (BI-RADS) breast density categories are associated with high interval cancer rates.

DESIGN

Prospective cohort.

SETTING

Breast Cancer Surveillance Consortium (BCSC) breast imaging facilities.

PATIENTS

365,426 women aged 40 to 74 years who had 831,455 digital screening mammography examinations.

MEASUREMENTS

BI-RADS breast density, BCSC 5-year breast cancer risk, and interval cancer rate (invasive cancer ≤12 months after a normal mammography result) per 1000 mammography examinations. High interval cancer rate was defined as more than 1 case per 1000 examinations.

RESULTS

High interval cancer rates were observed for women with 5-year risk of 1.67% or greater and extremely dense breasts or 5-year risk of 2.50% or greater and heterogeneously dense breasts (24% of all women with dense breasts). The interval rate of advanced-stage disease was highest (>0.4 case per 1000 examinations) among women with 5-year risk of 2.50% or greater and heterogeneously or extremely dense breasts (21% of all women with dense breasts). Five-year risk was low to average (0% to 1.66%) for 51.0% of women with heterogeneously dense breasts and 52.5% with extremely dense breasts, with interval cancer rates of 0.58 to 0.63 and 0.72 to 0.89 case per 1000 examinations, respectively.

LIMITATION

The benefit of supplemental imaging was not assessed.

CONCLUSION

Breast density should not be the sole criterion for deciding whether supplemental imaging is justified because not all women with dense breasts have high interval cancer rates. BCSC 5-year risk combined with BI-RADS breast density can identify women at high risk for interval cancer to inform patient-provider discussions about alternative screening strategies.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Use of bone morphogenetic protein among patients undergoing fusion for degenerative diagnoses in the United States, 2002 to 2012

BACKGROUND CONTEXT

Use of bone morphogenetic protein (BMP) as an adjunct to spinal fusion surgery proliferated after Food and Drug Administration (FDA) approval in 2002. Major safety concerns emerged in 2008.

PURPOSE

The purpose of this study was to examine whether published concerns about the safety of BMP altered clinical practice.

STUDY DESIGN/SETTING

The study design involved the analysis of the National Inpatient Sample from 2002 through 2012.

PATIENT SAMPLE

Adults (older than 20 years) undergoing an elective fusion operation for common degenerative diagnoses were identified using codes from the International Classification of Diseases, ninth revision, Clinical Modification.

OUTCOME MEASURES

Outcome measures were proportion of cervical and lumbar fusion operations, over time, that involved BMP.

METHODS

We aggregated the data into a monthly time series and reported the proportion of cervical and lumbar fusion operations, over time, that involved BMP. Autoregressive Integrated Moving Average, a regression model for time series data, was used to test whether there was a statistically significant change in the overall rate of BMP use after an FDA Public Health Notification in 2008.

RESULTS

Use of BMP in spinal fusion procedures increased rapidly until 2008, involving up to 45.2% of lumbar and 13.5% of cervical fusions. Bone morphogenetic protein use significantly decreased after the 2008 FDA Public Health Notification and revelations of financial payments to surgeons involved in the pivotal FDA-approved trials. For lumbar fusion, the average annual increase was 7.9 percentage points per year from 2002 to 2008, followed by an average annual decrease of 11.7 percentage points thereafter (p≤.001). Use of BMP in cervical fusion increased 2.0% per year until the FDA Public Health Notification, followed by a 2.8% per year decrease (p=.035).

CONCLUSIONS

Use of BMP in spinal fusion surgery declined subsequent to published safety concerns and revelations of financial conflicts of interest for investigators involved in the pivotal clinical trials.

Benefits, harms, and cost-effectiveness of supplemental ultrasonography screening for women with dense breasts

BACKGROUND

Many states have laws requiring mammography facilities to tell women with dense breasts and negative results on screening mammography to discuss supplemental screening tests with their providers. The most readily available supplemental screening method is ultrasonography, but little is known about its effectiveness.

OBJECTIVE

To evaluate the benefits, harms, and cost-effectiveness of supplemental ultrasonography screening for women with dense breasts.

DESIGN

Comparative modeling with 3 validated simulation models.

DATA SOURCES

Surveillance, Epidemiology, and End Results Program; Breast Cancer Surveillance Consortium; and medical literature.

TARGET POPULATION

Contemporary cohort of women eligible for routine screening.

TIME HORIZON

Lifetime.

PERSPECTIVE

Payer.

INTERVENTION

Supplemental ultrasonography screening for women with dense breasts after a negative screening mammography result.

OUTCOME MEASURES

Breast cancer deaths averted, quality-adjusted life-years (QALYs) gained, biopsies recommended after a false-positive ultrasonography result, and costs.

RESULTS OF BASE-CASE ANALYSIS

Supplemental ultrasonography screening after a negative mammography result for women aged 50 to 74 years with heterogeneously or extremely dense breasts averted 0.36 additional breast cancer deaths (range across models, 0.14 to 0.75), gained 1.7 QALYs (range, 0.9 to 4.7), and resulted in 354 biopsy recommendations after a false-positive ultrasonography result (range, 345 to 421) per 1000 women with dense breasts compared with biennial screening by mammography alone. The cost-effectiveness ratio was $325,000 per QALY gained (range, $112,000 to $766,000). Supplemental ultrasonography screening for only women with extremely dense breasts cost $246,000 per QALY gained (range, $74,000 to $535,000).

RESULTS OF SENSITIVITY ANALYSIS

The conclusions were not sensitive to ultrasonography performance characteristics, screening frequency, or starting age.

LIMITATION

Provider costs for coordinating supplemental ultrasonography were not considered.

CONCLUSION

Supplemental ultrasonography screening for women with dense breasts would substantially increase costs while producing relatively small benefits.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Treatment of Asymptomatic Hyperuricemia and Prevention of Vascular Disease: A Decision Analytic Approach

Objective.

Elevated serum urate may be associated with an increase in cardiovascular (CV) disease. Treating asymptomatic hyperuricemia with urate-lowering drugs such as allopurinol may reduce CV events. We designed a model to simulate the effect of allopurinol treatment on reducing frequency of CV events in individuals with elevated serum urate.

Methods.

A Markov state-transition model was constructed to assess occurrence of vascular events (VE) for 2 treatment strategies: treat all asymptomatic individuals with allopurinol (Treat All) and treat only if symptomatic (Treat Symptomatic). The model simulated a hypothetical cohort of 50-year-old men with different serum urate concentrations (6–6.9 and 7–7.9 mg/dl) followed over 20 years. Age and sex subgroups were analyzed. Model inputs were derived from current literature. The main outcome measures were mean number of VE and mean number of deaths from VE.

Results.

For 50-year-old men with serum urate 6.0–6.9 mg/dl, individuals in the Treat All strategy have a 30% reduction in the mean number of VE compared to those in the Treat Symptomatic strategy (mean VE: 0.078 vs 0.11), and a 39% reduction in mean number of deaths from VE. At higher serum urate concentrations, treatment is more effective in reducing the mean number of VE and mean number of deaths from VE (38% event, 54% death). Results for women show similar trends. As the cohort ages, treatment has less effect on reducing VE. The number needed to treat to prevent 1 event is 20 (men, 7.0–7.9 mg/dl).

Conclusion.

The model predicts that treating asymptomatic hyperuricemia with allopurinol is most effective in preventing VE at a serum urate above 7.0 mg/dl in men and 5.0 mg/dl in women.

Abstract P4-01-15: Impact of Preoperative MRI on the Surgical Treatment of Breast Cancer: A SEER-Medicare Analysis

Background: Preoperative magnetic resonance imaging (MRI) use has increased for women with invasive breast cancer and ductal carcinoma in situ (DCIS). Prior studies have disputed whether preoperative MRI is associated with increased rates of mastectomy. We evaluated the rates of mastectomy versus breast conserving surgery (BCS) and their association with preoperative MRI in older women.

Methods: We identified women in SEER-Medicare 66 years or older diagnosed with DCIS or invasive breast cancer between 2002 and 2007 treated within 6 months of diagnosis with mastectomy or breast conserving surgery (BCS) with or without radiotherapy (RT). Preoperative MRI was defined as MRI occurring before a woman's first surgery after her initial diagnosis. We looked for surgical treatment (BCS or mastectomy) and radiotherapy, age at diagnosis, year of diagnosis and cancer type, overall and separately by receipt of MRI. We examined the association of surgical treatment with MRI using multivariable logistic regression adjusting for age at diagnosis, year of diagnosis, cancer type and radiotherapy.

Results: Among the 70,758 women identified, 5,126 (7.2%) had a preoperative MRI. The overall use of MRI increased from 1.2% in 2002 to 18.0% in 2007 (p &lt; 0.0001). Women with MRI were more likely to undergo mastectomy than those without MRI (331 per 1000 vs. 314 per 1000; respectively, p &lt; 0.0001) and more likely to undergo BCS RT (432 per 1000 vs. 354 per 1000; respectively, p &lt; 0.0001).

Conclusion: The use of preoperative MRI has increased in recent years and is significantly associated with increased rates of BCS RT and mastectomy. Limitations of this study include that it is an observational analysis and that selection bias may exist for MRI and aggressive treatment that is not related to what is observed on MRI. Further studies are needed to understand how patient characteristics and information obtained from MRI influence treatment choices.

The cost-effectiveness of single-row compared with double-row arthroscopic rotator cuff repair

BACKGROUND

Interest in double-row techniques for arthroscopic rotator cuff repair has increased over the last several years, presumably because of a combination of literature demonstrating superior biomechanical characteristics and recent improvements in instrumentation and technique. As a result of the increasing focus on value-based health-care delivery, orthopaedic surgeons must understand the cost implications of this practice. The purpose of this study was to examine the cost-effectiveness of double-row arthroscopic rotator cuff repair compared with traditional single-row repair.

METHODS

A decision-analytic model was constructed to assess the cost-effectiveness of double-row arthroscopic rotator cuff repair compared with single-row repair on the basis of the cost per quality-adjusted life year gained. Two cohorts of patients (one with a tear of <3 cm and the other with a tear of ≥3 cm) were evaluated. Probabilities for retear and persistent symptoms, health utilities for the particular health states, and the direct costs for rotator cuff repair were derived from the orthopaedic literature and institutional data.

RESULTS

The incremental cost-effectiveness ratio for double-row compared with single-row arthroscopic rotator cuff repair was $571,500 for rotator cuff tears of <3 cm and $460,200 for rotator cuff tears of ≥3 cm. The rate of radiographic or symptomatic retear alone did not influence cost-effectiveness results. If the increase in the cost of double-row repair was less than $287 for small or moderate tears and less than $352 for large or massive tears compared with the cost of single-row repair, then double-row repair would represent a cost-effective surgical alternative.

CONCLUSIONS

On the basis of currently available data, double-row rotator cuff repair is not cost-effective for any size rotator cuff tears. However, variability in the values for costs and probability of retear can have a profound effect on the results of the model and may create an environment in which double-row repair becomes the more cost-effective surgical option. The identification of the threshold values in this study may help surgeons to determine the most cost-effective treatment.

Trends and variation in incidence, surgical treatment, and repeat surgery of proximal humeral fractures in the elderly

BACKGROUND

the treatment of proximal humeral fractures in the elderly remains controversial. Options include nonoperative treatment, open reduction with internal fixation (ORIF), and hemiarthroplasty. Locking plate technology has expanded the indications for ORIF for certain fracture types in osteoporotic bone. This study was performed to characterize the incidence, treatment, and revision surgery of proximal humeral fractures according to geographic region both before (1999 to 2000) and after (2004 to 2005) the introduction of locking plates.

METHODS

we used a 20% sample of Medicare Part-B data and the Medicare denominator file for the years 1998 to 2006. Proximal humeral fractures were identified by Common Procedural Terminology codes for treatment, categorized as nonoperative, ORIF, or hemiarthroplasty. Geographic variation in treatment type was determined with use of 306 hospital referral regions. Odds ratios for revision surgery were calculated by the need for repeat surgery within one year of the index procedure. Rates were adjusted for age, sex, race, and comorbidities.

RESULTS

there were 14,774 proximal humeral fractures in the 20% sample from 1999 to 2000 (an estimated total of 73,870 fractures) and 16,138 fractures in the sample from 2004 to 2005 (an estimated total of 80,690 fractures). The overall age, sex, and race-adjusted incidence of proximal humeral fractures was unchanged from 1999 to 2005 (2.47 vs. 2.48 per 1000 Medicare beneficiaries; p = 0.992). However, the absolute rate of surgically managed proximal humeral fractures rose 3.2 percentage points from 12.5% to 15.7%, a relative increase of 25.6% (p < 0.0001). The relative increase in the percentage of fractures treated with ORIF was 28.5% (p < 0.0001), while the percentage of fractures treated with hemiarthroplasty increased 19.6% (p < 0.0001). There were large regional variations in the proportion treated surgically (range, 0% to 68.18%). The rates of repeat surgery were significantly higher in 2004 to 2005 compared with 1999 to 2000 (odds ratio = 1.47, p = 0.043).

CONCLUSIONS

although the incidence of proximal humeral fractures in the elderly did not change from 1999 to 2005, the rate of surgical treatment increased significantly. The marked regional variation in the rates of surgical treatment highlights the need for better consensus regarding optimal treatment of proximal humeral fractures. Additional research is needed to help to determine which fractures are best treated operatively in order to maximize outcome and minimize the need for revision surgery.

LEVEL OF EVIDENCE

therapeutic Level II. See Instructions to Authors for a complete description of levels of evidence.

A longitudinal comparison of 5 preference-weighted health state classification systems in persons with intervertebral disk herniation

OBJECTIVE

To assess the longitudinal validity of widely used preference-weighted measurement systems for economic studies of intervertebral disk herniation (IDH).

METHODS

Using data at baseline and 1 year from 1000 Spine Patient Outcomes Research Trial (SPORT) participants with IDH and complete data, the authors considered the EQ-5D with UK and US values (EQ-5D-UK and EQ-5D-US), 2 versions of the Health Utilities Index (HUI3 and HUI2), the SF-6D, and a regression-estimated quality of well-being score (eQWB). Differences in mean change scores (MCS) were assessed using signed rank tests, and Spearman correlations were calculated for change scores by system pairs. Using the Oswestry Disability Index, symptom satisfaction, progress rating, and self-perceived health ratings as criterion measures, the authors tested for trend in MCS across levels of change in criteria. They calculated floor and ceiling effects, effect size (ES), standardized response mean, and minimal important difference estimates.

RESULTS

All systems demonstrated linear trends with external criteria and moderate to strong correlations between systems. However, differences in performance were evident. SF-6D and eQWB were most responsive (ES: 1.9 and 2.3, respectively), whereas EQ-5D-US and EQ-5D-UK were least responsive (ES: 1.23/1.20). Ceiling and floor effects were noted for all systems within key dimensions and for EQ-5D-UK and EQ-5D-US for overall score. MCS ranged from 0.40 (0.38) for EQ-5D-UK to 0.13 (0.09) for eQWB and differed significantly, except between EQ-5D-US and HUI2.

CONCLUSIONS

This research supports the validity of all systems for measuring change in persons with IDH, without finding a clearly superior system. The unique characteristics of each system revealed in this study should guide system choice.

A cost-effectiveness analysis of the arthroplasty options for displaced femoral neck fractures in the active, healthy, elderly population

This study was performed to explore the cost-effectiveness of total hip arthroplasty (THA) compared with hemiarthroplasty (HEMI) in the treatment of displaced femoral neck fractures in active otherwise healthy older patients in whom the optimum treatment is believed to be an arthroplasty procedure. A Markov decision model was used to determine whether THA or HEMI was most cost-effective for the management of a displaced femoral neck fracture in this patient population. Total hip arthroplasty was associated with an average cost $3000 more than HEMI, and the average quality-adjusted life year gain was 1.53. The incremental cost-effectiveness ratio associated with the THA treatment strategy is $1960 per quality-adjusted life year. Currently available data support the use of THA as the more cost-effective treatment strategy in this specific population. The increased upfront cost appears to be offset by the improved functional results when compared with HEMI in this select patient group.

Surgical compared with nonoperative treatment for lumbar degenerative spondylolisthesis. four-year results in the Spine Patient Outcomes Research Trial (SPORT) randomized and observational cohorts

BACKGROUND

The management of degenerative spondylolisthesis associated with spinal stenosis remains controversial. Surgery is widely used and has recently been shown to be more effective than nonoperative treatment when the results were followed over two years. Questions remain regarding the long-term effects of surgical treatment compared with those of nonoperative treatment.

METHODS

Surgical candidates from thirteen centers with symptoms of at least twelve weeks' duration as well as confirmatory imaging showing degenerative spondylolisthesis with spinal stenosis were offered enrollment in a randomized cohort or observational cohort. Treatment consisted of standard decompressive laminectomy (with or without fusion) or usual nonoperative care. Primary outcome measures were the Short Form-36 (SF-36) bodily pain and physical function scores and the modified Oswestry Disability Index at six weeks, three months, six months, and yearly up to four years.

RESULTS

In the randomized cohort (304 patients enrolled), 66% of those randomized to receive surgery received it by four years whereas 54% of those randomized to receive nonoperative care received surgery by four years. In the observational cohort (303 patients enrolled), 97% of those who chose surgery received it whereas 33% of those who chose nonoperative care eventually received surgery. The intent-to-treat analysis of the randomized cohort, which was limited by nonadherence to the assigned treatment, showed no significant differences in treatment outcomes between the operative and nonoperative groups at three or four years. An as-treated analysis combining the randomized and observational cohorts that adjusted for potential confounders demonstrated that the clinically relevant advantages of surgery that had been previously reported through two years were maintained at four years, with treatment effects of 15.3 (95% confidence interval, 11 to 19.7) for bodily pain, 18.9 (95% confidence interval, 14.8 to 23) for physical function, and -14.3 (95% confidence interval, -17.5 to -11.1) for the Oswestry Disability Index. Early advantages (at two years) of surgical treatment in terms of the secondary measures of bothersomeness of back and leg symptoms, overall satisfaction with current symptoms, and self-rated progress were also maintained at four years.

CONCLUSIONS

Compared with patients who are treated nonoperatively, patients in whom degenerative spondylolisthesis and associated spinal stenosis are treated surgically maintain substantially greater pain relief and improvement in function for four years.

Impact of hip and vertebral fractures on quality-adjusted life years

The objective of the study was to estimate the impact of hip and vertebral fractures on quality of life in postmenopausal women using a preference-based health measure that is appropriate for economic evaluations and to investigate correlates of health outcome. Interviews to assess health-related quality of life, which also documented other health conditions and characteristics, were undertaken in women age 50 years and older without osteoporotic fractures compared with women with hip and/or vertebral fracture(s). Health status was characterized by self-reported physical limitations and the mental and physical component summary scores of the SF-36. Quality-adjusted life years (QALYs), which reflect each individual's assessment of her overall health utility, were estimated with time tradeoff values. Regression methods were used to examine QALY correlates (e.g. time since fracture) for each fracture group and to estimate differences in QALYs between fracture and non-fracture subjects after accounting for other patient characteristics. Among 382 women ages 50-96 years, fracture subjects were significantly older, less likely to use hormone replacement therapy and more likely to report physical limitations than non-fracture subjects. On the QALY scale, where 1 represents perfect health and 0 represents death, mean QALY values were 0.82 (95% CI: 0.76, 0.87) among 114 women with one or more vertebral fractures and 0.63 (95% CI: 0.52, 0.74) among 67 with hip fracture compared with 0.91 (95% CI: 0.88, 0.94) among 201 women without fracture. No significant correlates of QALYs were identified among women with vertebral fracture alone. Among hip fracture subjects, time since hip fracture and presence of a vertebral fracture were significant correlates of QALYs. In multiple regression analyses, estimated QALY differences (fracture minus non-fracture subjects) ranged from -0.05 to -0.55 and were equivalent to losses of 20-58 days, 23-65 days and 115-202 days per year for vertebral fracture (p = 0.001), hip fracture (p = 0.009) and hip plus vertebral fracture (p<0.001) subjects, respectively, depending on age. Thus to adequately assess the cost-effectiveness of osteoporosis treatment, the negative impact of vertebral fractures on QALYs, even among women who have survived a hip fracture, must be considered.

Skin test reactions to Mycobacterium tuberculosis purified protein derivative and Mycobacterium avium sensitin among health care workers and medical students in the United States

SETTING

Health care workers and medical students in the United States subject to annual tuberculin skin testing.

OBJECTIVE

To use skin testing with Mycobacterium avium sensitin (MAS) to determine contemporary rates of infection with non-tuberculous mycobacteria (NTM) and their effect on reactions to M. tuberculosis purified protein derivative (PPD).

DESIGN

Dual skin testing was performed with PPD and MAS on 784 health care workers and medical students in the northern and southern US. MAS reactions that were > or = 5 mm and also > or = 3 mm larger than the PPD reaction were defined as MAS dominant and due to NTM.

RESULTS

MAS reactions were > or = 5 mm in 40% and > or = 15 mm in 18% of subjects; 95% were MAS dominant. MAS dominant reactions were more common in the south than the north (P < 0.001). PPD reactions were > or = 15 mm in 3% of subjects. PPD reactions > or = 15 mm were more common among males, foreign born subjects and subjects with BCG immunization (all P < 0.001). MAS dominant reactions were found in 82% of subjects with 5-9 mm PPD reactions and 50% with 10-14 mm PPD reactions; these reactions were more common among whites (P = 0.046), US-born (P = 0.038) and subjects without BCG immunization (P = 0.004).

CONCLUSIONS

Infections with NTM are responsible for the majority of 5-14 mm PPD reactions among US-born health care workers and medical students subject to annual tuberculin testing.

A comparison of treatment strategies for hypoplastic left heart syndrome using decision analysis

OBJECTIVES

We sought to identify the optimal treatment strategy for hypoplastic left heart syndrome (HLHS).

BACKGROUND

Surgical treatment of HLHS involves either transplantation (Tx) or staged palliation of the native heart. Identifying the best treatment for HLHS requires integrating individual patient risk factors and center-specific data.

METHODS

Decision analysis is a modeling technique used to compare six strategies: staged surgery; Tx; stage 1 surgery as an interim to Tx; and listing for transplant for one, two, or three months before performing staged surgery if a donor is unavailable. Probabilities were derived from current literature and a dataset of 231 patients with HLHS born between 1989 and 1994. The goal was to maximize first-year survival.

RESULTS

If a donor is available within one month, Tx is the optimal choice, given baseline probabilities; if no donor is found by the end of one month, stage 1 surgery should be performed. When survival and organ donation probabilities were varied, staged surgery was the optimal choice for centers with organ donation rates < 10% in three months and with stage 1 mortality <20%. Waiting one month on the transplant list optimized survival when the three-month organ donation rate was > or =30%. Performing stage 1 surgery before listing, or performing stage 1 surgery after an unsuccessful two- or three-month wait for transplant, were almost never optimal choices.

CONCLUSIONS

The best strategy for centers that treat patients with HLHS should be guided by local organ availability, stage 1 surgical mortality and patient risk factors.

Assessing values for health: numeracy matters

BACKGROUND

Patients' values are fundamental to decision models, cost-effectiveness analyses, and pharmacoeconomic analyses. The standard methods used to assess how patients value different health states are inherently quantitative. People without strong quantitative skills (i.e., low numeracy) may not be able to complete these tasks in a meaningful way.

METHODS

To determine whether the validity of utility assessments depends on the respondent's level of numeracy, the authors conducted in-person interviews and written surveys and assessed utility for the current health for 96 women volunteers. Numeracy was measured using a previously validated 3-item scale. The authors examined the correlation between self-reported health and utility for current health (assessed using the standard gamble, time trade-off, and visual analog techniques) across levels of numeracy. For half of the women, the authors also assessed standard gamble utility for 3 imagined health states (breast cancer, heart disease, and osteoporosis) and asked how much the women feared each disease.

RESULTS

Respondent ages ranged from 50 to 79 years (mean = 63), all were high school graduates, and 52% had a college or postgraduate degree. Twenty-six percent answered 0 or only 1 of the numeracy questions correctly, 37% answered 2 correctly, and 37% answered all 3 correctly. Among women with the lowest level of numeracy, the correlation between utility for current health and self-reported health was in the wrong direction (i.e., worse health valued higher than better health): for standard gamble, Spearman r=-0.16, P = 0.44;for time trade-off, Spearman r=-0.13, P=0.54. Among the most numerate women, the authors observed a fair to moderate positive correlation with both standard gamble (Spearman r=0.22, P=0.19) and time trade-off (Spearman r=0.50, P=0.002). In contrast, using the visual analog scale, the authors observed a substantial correlation in the expected direction at all levels of numeracy (Spearman r= 0.82, 0.50, and 0.60 for women answering 0-1, 2, and 3 numeracy questions, respectively; all Ps < or = 0.003). With regard to the imagined health states, the most feared disease had the lowest utility for 35% of the women with the lowest numeracy compared to 76% of the women with the highest numeracy (P=0.03).

CONCLUSIONS

The validity of standard utility assessments is related to the subject's facility with numbers. Limited numeracy may be an important barrier to meaningfully assessing patients' values using the standard gamble and time trade-off techniques.

Initiation of osteoporosis treatment after bone mineral density testing

The aim of the study was to describe initiation of osteoporosis drug therapy after bone mineral density (BMD) testing and to determine any association with BMD test results obtained, physician factors, or both. The setting was the Kaiser Foundation Health Plan (KFHP), a large health maintenance organization (HMO) in Northern California. Data were collected from bone densitometry centers at four KFHP medical centers sites in Sacramento, San Rafael, Fresno, and Oakland. We identified 17,290 women aged > or = 45 years who had BMD testing between January 1, 1997 and June 30, 1999. After excluding those for whom any osteoporosis drugs were prescribed in the year before testing, 8020 women were available for analysis. Using logistic regression, we examined the association between BMD diagnosis (i.e., osteoporosis or osteopenia versus normal) and initiation of drug therapy, for osteoporosis (including hormone replacement therapy (HRT), alendronate, etidronate, raloxifene and calcitonin) within 6 months after the test. Among the 8020 women, 1934 (24%) filled a prescription for an osteoporosis drug within 6 months after BMD testing. Compared with women who had a normal BMD test result, women diagnosed with osteopenia were nearly 4 times more likely (OR = 3.7; CI = 3.0-4.4), and women diagnosed with osteoporosis were 15 times more likely (OR = 15.0; CI = 12.5-18.1), to fill a prescription for an osteoporosis drug within 6 months after BMD testing. Women with high exposure to corticosteroid agents were twice as likely (OR = 2.1; CI = 1.7-2.7) to start osteoporosis drug therapy compared with women who were not similarly exposed; women diagnosed with recent osteoporotic fractures were 50% more likely (OR = 1.5; CI = 1.2-1.9) to begin therapy than women without such fractures. Despite the strong association between BMD and initiating treatment, nearly half the osteoporotic women did not initiate treatment. In addition, we found that age strongly influenced choice of osteoporotic drug. Compared with osteoporotic women aged 45-54 years, women aged 55-64 years who started drug therapy were 40% more likely (OR = 1.4; CI = 1.0-2.2) and women aged > or = 65 years were twice as likely (OR = 2.0; CI = 1.4-2.8) to start non-HRT drugs. BMD test results indicating osteoporosis were thus strongly associated with increased likelihood of beginning drug therapy, and half of such women initiated therapy. Drug initiation was also associated with other factors, including age, use of corticosteroid agents, recent fracture, and physician characteristics. However, these factors showed much weaker associations than those found for BMD. Health care providers must consider whether test results will influence treatment decisions, and our data indicate that results of BMD testing do influence management decisions regarding osteoporosis drug use for women.

Challenges for model-based economic evaluations of postmenopausal osteoporosis interventions

Assessing the cost-effectiveness of long-term treatment for osteoporosis requires use of mathematical models to estimate health effects and costs for competing interventions. The primary motivations for model-based analyses include the lack of long-term clinical trial outcome data and the lack of data comparing all relevant treatments within randomized clinical trials. We report on specific modeling challenges that arose in the development of a model of the natural history of postmenopausal osteoporosis that is suitable for assessing the cost-effectiveness of osteoporosis interventions among various population subgroups in diverse countries. These include choice of modeling changes in bone mineral density (BMD) or in fracture rate, definition of health states, modeling mortality and costs of long-term care following fracture, incorporation of health utility, and model validation. This report should facilitate future postmenopausal osteoporosis model development and provide insight for decision-makers who must evaluate model-based economic analyses of postmenopausal osteoporosis interventions.

Preference-based health outcome measures in low back pain

Preference-based health outcome measures were considered in two settings. In the clinical context, utility assessment using the VAS, TTO or SG was described. It is recognized that formal utility assessment is generally not needed in day-to-day clinical practice. When the need to explicitly value alternative health outcomes arises, the VAS is recommended because of its ease of implementation. In the health policy context, preference classification systems are recommended for valuing health when a cost-effectiveness analysis of alternative health care interventions is planned. At present, there is little evidence to base choice of one system over another for assessing the cost-effectiveness of low back pain interventions.

Prosthetic valve type for patients undergoing aortic valve replacement: a decision analysis

BACKGROUND

In two large, randomized, clinical trials long-term survival after aortic valve replacement (AVR) was similar for patients receiving tissue and mechanical aortic heart valve prostheses. Higher bleeding rates among patients with mechanical valves, who must receive permanent oral anticoagulation to prevent thromboembolism, were offset by higher reoperation rates for valve degeneration among patients with tissue valves. Because the average age of patients undergoing AVR and clinical practices have changed considerably since the randomized clinical trials were conducted, we performed a decision analysis to reassess the optimal valve type for patients undergoing AVR.

METHODS

We used a Markov state-transition model to simulate the occurrence of valve-related events and life expectancy for patients undergoing AVR. Probabilities of clinical events and mortality were derived from the randomized clinical trials and large follow-up studies.

RESULTS

Although the two valve types were associated with similar life expectancy in 60-year-old patients (mean age of patients in the randomized clinical trials), tissue valves were associated with greater life expectancy than mechanical valves (10.7 versus 11.1 years) in 70-year-old patients (currently mean age of AVR patients). For 70-year-old patients, the effects of major bleeding complications (24%) with mechanical valves substantially outweighed those of reoperation for valve failure (12%) with tissue valves at 12 years. Of the clinical practice changes assessed, the recommended valve type was most sensitive to changes in bleeding rates with anticoagulation. However, bleeding rates would have to be 68% lower than those reported in the European randomized clinical trial to affect the recommended valve type for 70-year-old patients. Reoperation rates would have to be five times higher, and mortality rates at reoperation would have to be four times higher to affect the recommended valve type for 70-year-old patients.

CONCLUSIONS

Although mechanical valves are preferred for AVR patients less than 60 years old, most patients currently undergoing AVR are elderly and would benefit more from tissue valves.

Mammography in 53,803 women from the New Hampshire mammography network

PURPOSE

To describe measures of mammography performance in a geographically defined population and evaluate the interpreter's use of the Breast Imaging Reporting and Data System (BI-RADS).

MATERIALS AND METHODS

Mammographic data from 47,651 screening and 6,152 diagnostic examinations from November 1, 1996, to October 31, 1997, were linked to 1,572 pathologic results. Mammographic outcomes were based on BI-RADS assessments and recommendations reported by the interpreting radiologist. The consistency of BI-RADS recommendations was evaluated.

RESULTS

Screening mammography had a sensitivity of 72.4% (95% CI: 66.4%, 78.4%), specificity of 97.3% (95% CI: 97.25%, 97.4%), and positive predictive value of 10.6% (95% CI: 9.1%, 12.2%). Diagnostic mammography had higher sensitivity, 78.1% (95% CI: 71.9%, 84.3%); lower specificity, 89.3% (95% CI: 88.5%, 90.1%); and better positive predictive value, 17.1% (95% CI: 14.5%, 19.8%). The cancer detection rate with screening mammography was 3.3 per 1,000 women, with a biopsy yield of 22.4%, whereas the interval cancer rate was 1. 2 per 1,000. Nearly 80% of screening-detected invasive malignancies were node negative. The recall rate for screening mammography was 8. 3%. Ultrasonography was used in 3.5% of screening and 17.5% of diagnostic examinations. BI-RADS recommendations were generally consistent, except for probably benign assessments.

CONCLUSION

The sensitivity of screening mammography in this population-based sample is lower than expected, although other performance indicators are commendable. BI-RADS "probably benign" assessments are commonly misused.

Survival analysis and risk factors for mortality in transplantation and staged surgery for hypoplastic left heart syndrome

OBJECTIVES

We compared survival in treatment strategies and determined risk factors for one-year mortality for hypoplastic left heart syndrome (HLHS) using intention-to-treat analysis.

BACKGROUND

Staged revision of the native heart and transplantation as treatments for HLHS have been compared in treatment-received analyses, which can bias results.

METHODS

Data on 231 infants with HLHS, born between 1989 and 1994 and intended for surgery, were collected from four pediatric cardiac surgical centers. Status at last contact for survival analysis and mortality at one year for risk factor analysis were the outcome measures.

RESULTS

Survival curves showed improved survival for patients intended for transplantation over patients intended for staged surgery. One-year survival was 61% for transplantation and 42% for staged surgery (p < 0.01); five-year survival was 55% and 38%, respectively (p < 0.01). Survival curves adjusted for preoperative differences were also significantly different (p < 0.001). Waiting-list mortality accounted for 63% of first-year deaths in the transplantation group. Mortality with stage 1 surgery accounted for 86% of that strategy's first-year mortality. Birth weight <3 kg (odds ratio [OR] 2.4), highest creatinine > or =2 mg/dL (OR 4.7), restrictive atrial septal defect (OR 2.7) and, in staged surgery, atresia of one (OR 4.2) or both (OR 11.0) left-sided valves produced a higher risk for one-year mortality.

CONCLUSIONS

Transplantation produced significantly higher survival at all ages up to seven years. Patients with atresia of one or both valves do poorly in staged surgery and have significantly higher survival with transplantation. This information may be useful in directing patients to the better strategy for them.

Measuring health state preferences in women with breast hypertrophy

The purpose of this article is to introduce the measurement of utilities, or patient preferences, to the plastic surgery community. Specifically, the study demonstrated the development and validation of a utility measure for estimating the health-related quality of life in women with breast hypertrophy. Two self-administered instruments were developed, a Wheel and a Table. All subjects completed the utility assessments for their "current health" and again for "breast-related symptoms." The reliability of the instruments was assessed in repeat (test-retest) interviews of 47 women within 10 to 18 days. Utilities obtained with the new instruments were also compared with the performance of other validated utility assessment instruments, including a visual analogue scale, a computer-based instrument (U-Titer), and a preference classification system (EuroQol). Of the 47 women in the test-retest reliability study, 21 had experienced breast hypertrophy (13 had not had reduction surgery and 8 had undergone reduction mammaplasty). Mean utility values for breast-related symptoms among women with breast hypertrophy (n = 13) were: Table, 0.85; Wheel, 0.90; and U-Titer, 0.66. Current health utility scores were significantly lower for women with breast hypertrophy (n = 13), as measured by all instruments except the Wheel. The Table had good reliability and distinguished women with breast hypertrophy from those without. Although the Table provided higher utility values for the same health state compared with the computer-based interview (U-Titer), it is much less costly to implement. The Table is recommended as a reasonable alternative for use in multicenter studies of women with breast hypertrophy. The reported utility value for breast hypertrophy of 0.86 is much lower than predicted. It is comparable with the reported burden of living with other health conditions, such as moderate angina (0.90) and a kidney transplant (0.84).

Mammography in New Hampshire: characteristics of the women and the exams they receive

New Hampshire (NH) is one of two states that has developed a population-based mammography registry. The purpose of this paper is to describe what we have learned about mammography use in New Hampshire. After collecting data for 20 months, the database contains almost 110,000 mammographic encounters representing 101,679 NH women, who range in age from 18 to 97 with a mean of 56.7 years (SD=10.91). Education levels are high with 92% having a high school education and 59% with some college. Forty-six percent report their primary insurance is private, 29% report HMO/PPO coverage, and 25% receive federal health care assistance. Risk factors represented in the database include (categories not mutually exclusive) advancing age (60% over age 50), hormone replacement therapy use by menopausal women (40.6%), and a family history of breast cancer (29%). Penetration of mammography relative to the NH population is higher for younger age groups (40-48% for those aged 44-64) than older age groups (34-39% for those aged 65-84). The majority of mammographic encounters are routine screening exams (86%), often interpreted as negative or normal with benign findings (88%). Use of comparison films to interpret either diagnostic or screening mammography occurred in 86% of encounters. We have matched 3,877 breast pathology records to these mammographic encounters. The distribution of pathology outcomes for diagnostic exams was very similar to that for screening exams (approximately 65% benign, 17% invasive breast cancer, and 6% noninvasive breast cancer). Overall, we have designed a system that is well accepted by the NH community. Challenges include careful monitoring of data for coding errors, and a limitation of linking variables in mammography and pathology data. Data represented in this registry are a critical resource for research in mammographic screening and breast cancer early detection.

Safety and immunogenicity of a five-dose series of inactivated Mycobacterium vaccae vaccination for the prevention of HIV-associated tuberculosis

Five doses of inactivated Mycobacterium vaccae vaccine were administered intradermally to 22 human immunodeficiency virus (HIV)-infected patients (11 bacille Calmette-Guérin [BCG]-positive and 11 BCG-negative) in Zambia whose CD4 lymphocyte counts were >/=200 cells/mm(3). HIV viral load and lymphocyte proliferation responses were compared for vaccine recipients and 22 HIV-infected control patients (11 BCG-positive and 11 BCG-negative). Immunization was safe and well tolerated in all patients, and induration at the vaccine site decreased from dose 1 to dose 5. A transient decrease in HIV viral load was observed in BCG-positive vaccine recipients after dose 3 but not after subsequent doses. Median lymphocyte stimulation indices to M. vaccae were 6.0 in vaccine recipients and 2.3 in control patients (P<.001). Stimulation indices were >/=3.0 in 19 vaccine recipients (86%) and 7 control patients (32%; P=.001). A 5-dose series of vaccination with inactivated M. vaccae is safe in HIV-infected patients and induces lymphocyte proliferation responses to the vaccine antigen. M. vaccae vaccine is a candidate for the prevention of tuberculosis in HIV infection.

Pathologists' agreement with experts and reproducibility of breast ductal carcinoma-in-situ classification schemes

Several histologic classifications for breast ductal carcinoma in situ (DCIS) have been proposed. This study assessed the diagnostic agreement and reproducibility of three DCIS classifications (Holland [HL], modified Lagios [LA], and Van Nuys [VN]) by comparing the interpretations of pathologists without expertise in breast pathology with those of three breast pathology experts, each a proponent of one classification. Seven nonexpert pathologists in New Hampshire and three experts evaluated 40 slides of DCIS according to the three classifications. Twenty slides were reinterpreted by each nonexpert pathologist. Diagnostic accuracy (nonexperts compared with experts) and reproducibility were evaluated using inter- and intrarater techniques (kappa statistic). Final DCIS grade and nuclear grade were reported most accurately among nonexpert pathologists using HL (kappa = 0.53 and 0.49, respectively) compared with LA and VN (kappa = 0.29 and 0.35, respectively, for both classifications). An intermediate DCIS grade was assessed most accurately using HL and LA, and a high grade (group 3) was assessed most accurately using VN. Diagnostic reproducibility was highest using HL (kappa = 0.49). The VN interpretation of necrosis (present or absent) was reported more accurately than the LA criteria (extensive, focal, or absent; kappa = 0.59 and 0.45, respectively), but reproducibility of each was comparable (kappa = 0.48 and 0.46, respectively). Intrarater agreement was high overall. Comparing all three classifications, final DCIS grade was reported best using HL. Nuclear grade (cytodifferentiation) using HL and the presence or absence of necrosis were the criteria diagnosed most accurately and reproducibly. Establishing one internationally approved set of interpretive definitions, with acceptable accuracy and reproducibility among both pathologists with and without expertise in breast pathology interpretation, will assist researchers in evaluating treatment effectiveness and characterizing the natural history of DCIS breast lesions.

Has the impact of hormone replacement therapy on health-related quality of life been undervalued?

Previous economic evaluations of hormone replacement therapy (HRT) have restricted positive effects to alleviation of postmenopausal symptoms and negative effects to drug side effects. We studied the association between HRT use and postmenopausal women's valuation of both health-related quality of life and potential treatment side effects. Postmenopausal women with either a documented first vertebral fracture within the past 5 years or no history of osteoporotic fractures were recruited from Olmsted County, Minnesota, and from Dartmouth-Hitchcock Medical Center in New Hampshire to participate in a study to assess quality of life and women's attitudes toward osteoporosis prevention. Women's valuations of their current health and potential HRT-related side effects were quantified as quality-adjusted life years (QALYs) assessed by an automated utility assessment instrument (U-Titer) and the time tradeoff technique, by a vertical rating scale, and by estimated quality of well-being (QWB) scores. Health status was measured using the Medical Outcomes Study SF-36. Regression methods were used to assess the impact of current HRT use on health-related quality of life and valuation of side effects. There were 106 women with vertebral fracture and 180 with no history of hip, wrist, or vertebral fractures. Altogether, 116 (40.6%) women were currently taking HRT, 64 (22.2%) had taken HRT in the past, and 106 (37.1%) women had never taken HRT. Current HRT users had higher time tradeoff QALYs than never and past HRT users, with gains ranging from 15.0 to 83.7 days per year for current users relative to the others. Benefits were largest for women with a vertebral fracture and limitations in activities. The secondary QALY measures also showed significantly higher values for current HRT users compared with other women, as did SF-36 subscales for general health, physical function, role-emotional function, and vitality. There was substantial variability in women's perceptions of HRT side effects. Overall, the proportion of women willing to trade time to avoid bleeding was largest, at 95.5%, followed by breast tenderness, weight gain, and endometrial biopsy at 90.4%, 87.4%, and 82.7%, respectively. Current HRT users had higher health-related quality of life than past or never users according to all measures studied. Women's perceptions of potential side effects were highly variable and should be considered by physicians when prescribing an HRT regimen. If, as our results suggest, postmenopausal therapy has positive effects beyond the immediate postmenopausal years, previous economic studies may have underestimated the value of HRT.

Estimating the population impact of an intervention: a decision-analytic approach

The aim of this paper is to highlight the role for decision analysis in assessing outcomes of medical interventions at a population level. The basic steps of decision analysis are introduced and an illustrative hypothetical preventive intervention is examined. Specific modelling challenges that arise when estimating the population impact of an intervention are described and each is accompanied by an example. Decision analysis can provide useful information for health policy decision makers by identifying the intervention(s) with the largest beneficial impact on health over a wide range of assumptions. In addition, by focusing attention on the parameters with the greatest influence on projected outcomes, decision analysis can aid in identifying critical areas for future research.