Susan Stewart - Academia.edu (original) (raw)

Papers by Susan Stewart

Urology, 2004

Objectives. The purposes of this study were to estimate the difference in quality-adjusted life-y... more Objectives. The purposes of this study were to estimate the difference in quality-adjusted life-years between conservative management and prostatectomy or radiotherapy (RT) by clinical Gleason score (2 to 4, 5 to 6, 7, and 8 to 10) for patients aged 55 years and older with clinically localized prostate cancer and to adjust for and explore the effects of lead-time. For localized prostate cancer, it is not known whether treatment (prostatectomy or RT) results in longer quality-adjusted survival than conservative management. Observed survival benefits after treatment may be biased by the lead-time resulting from early diagnosis with prostate-specific antigen screening. Methods. A Markov simulation was developed, and transition probabilities were derived from a review of published studies. Utility weights were measured in male volunteers older than 60 years. Estimates of disease progression during conservative management were adjusted for lead-time. Sensitivity analyses were performed on all parameters (including estimates for lead-time). Results. For Gleason score 2 to 4 cancer, conservative management yielded the greatest number of quality-adjusted life-years. For Gleason score 5 to 6 cancer, any of the options appeared beneficial, depending on the estimates for disease progression. For Gleason score 7 to 10 cancer, prostatectomy and RT resulted in more quality-adjusted life-years than conservative management; with a lead-time adjustment of greater than 10 years, the outcomes with conservative management and prostatectomy were similar. The choice between prostatectomy and RT was sensitive to estimates of disease progression after treatment. Conclusions. Conservative management is a reasonable option for Gleason score 2 to 4 cancer and for some patients with Gleason score 5 to 6 cancer. Prostatectomy or RT is recommended for Gleason score 7 to 10 cancer. The survival benefits after treatment were not explained by the lead-time alone. UROLOGY 63: 103-109, 2004.

The Journal of Urology, 2006

Background: Recruitment of patients into cancer research studies is exceedingly difficult, partic... more Background: Recruitment of patients into cancer research studies is exceedingly difficult, particularly for early phase trials. Payer reimbursement policies are a frequently cited barrier. We examined whether state policies that ensure coverage of routine medical care costs for cancer trial participants are associated with an increase in clinical trial enrollment. Methods: We used logistic Poisson regressions to analyze enrollment in National Cancer Institute phase II and phase III Clinical Trials Cooperative Group trials and compared changes in trial enrollment rates between 1996 and 2001 of privately insured cancer patients who resided in the four states that enacted coverage policies in 1999 with enrollment rates in states without such policies. All statistical tests were two-sided. Results: Trial enrollment rates increased in the coverage and noncoverage states by 24.9% (95% confidence interval [CI] ϭ 22.8% to 27.0%) and 28.8% (95% CI ϭ 27.7% to 29.8%) per year, respectively, from 1996 through 2001. After implementation of the coverage policies in 1999 in four states, there was a 21.7% (95% CI ϭ 3.8% to 42.6%) annual increase in phase II trial enrollment in coverage states, compared with a 15.6% (95% CI ϭ 8.8% to 21.8%) annual decrease in noncoverage states (P Ͻ .001). After accounting for secular trend, cancer type, and race in multivariable analyses, the odds ratio (OR) for a phase II trial participant residing in a coverage versus a noncoverage state after 1999 was 1.59 per year (95% CI ϭ 1.22 to 2.07; P ϭ.001). In a multivariable analysis of phase III trial participation, there was a decrease in the odds of residing in a coverage state after 1999 (OR ϭ 0.90, 95% CI ϭ 0.84 to 0.98; P ϭ .011). Conclusion: State coverage policies were associated with a statistically significant increase in phase II cancer trial participation and did not increase phase III cancer trial enrollment. Editorial Comment: Randomized clinical trials are the gold standard for determining the efficacy of cancer therapies. Unfortunately, less than 3% of adult patients with cancer participate in clinical research studies. Numerous factors hinder enrollment of eligible patients. In an attempt to improve access of patients to cancer trials 15 states have passed legislative mandates or entered into mutual agreements with large health plans to ensure reimbursement of routine medical costs for clinical trial participants. Unfortunately, these efforts have yielded mixed results. The legislation appears to have had a positive impact on phase II studies. These are the studies designed to test drug safety and appropriate dosing. However, the legislation does not appear to have increased enrollment in phase III studies. These studies are the definitive trials designed to test treatment efficacy. Encouraging increased participation in clinical studies appears to be a complex issue that requires considerably more public education.

While health care cost growth in the United States has slowed in the past few years (Hartman et a... more While health care cost growth in the United States has slowed in the past few years (Hartman et al. 2015), health costs are projected to grow faster than the economy over the next decade (Cutler and Sahni 2013; Sisko et al. 2014; Keehan et al. 2015) and are one of the biggest fi scal challenges to the nation. As such, policymakers and analysts regularly try to better understand the value of this spending, so as to target cost containment eff orts to curb excess-rather than essential-spending. Unfortunately, there is often a mismatch between the data that are available and what policymakers need. Current National Health Expenditure Accounts measure medical spending at the level of the payers (Medicare, Medicaid, private insurance, etc.) and recipient of funds (hospital, physicians' offi ce, pharmaceutical company, etc.). However, measuring the value of medical spending requires relating expenditures to the health outcomes

This paper is motivated by two facts. The first is the large and growing share of people who rece... more This paper is motivated by two facts. The first is the large and growing share of people who receive disability insurance for pain-related conditions. About 40% of older adults have chronic pain, and musculoskeletal conditions (including back and neck pain, arthritis, and related maladies) are the most common conditions leading people to enroll in Social Security Disability Insurance (SSDI; SSA 2015). The second fact is the enormous increase in availability of opioid medications in recent years. Figure 1 shows national shipments of pain-relieving medications, taken from the Drug Enforcement Administration's ARCOS records. The figure shows morphine milligram equivalents (MMEs) per adult per year; 1,400 milligrams is more than one 30-day prescription per adult per year. Between 2001 and 2010, shipments of pain relievers increased by a factor of nearly four. They have remained at that level since.

This paper is motivated by two facts. The first is the large and growing share of people who rece... more This paper is motivated by two facts. The first is the large and growing share of people who receive disability insurance for pain-related conditions. About 40% of older adults have chronic pain, and musculoskeletal conditions (including back and neck pain, arthritis, and related maladies) are the most common conditions leading people to enroll in Social Security Disability Insurance (SSDI; SSA 2015). The second fact is the enormous increase in availability of opioid medications in recent years. Figure 1 shows national shipments of pain-relieving medications, taken from the Drug Enforcement Administration's ARCOS records. The figure shows morphine milligram equivalents (MMEs) per adult per year; 1,400 milligrams is more than one 30-day prescription per adult per year. Between 2001 and 2010, shipments of pain relievers increased by a factor of nearly four. They have remained at that level since.

JAMA, 2010

N 2009, 192 000 MEN WERE DIAGnosed as having prostate cancer in the United States. Of these men, ... more N 2009, 192 000 MEN WERE DIAGnosed as having prostate cancer in the United States. Of these men, 70% will have been classified as having low-risk, clinically localized disease, and more than 90% will have undergone initial treatment. 1-4 Initial treatment choices include surgical resection or radiation therapy. The majority of men experience at least 1 adverse effect of treatment. 5-7 In the era of prostate-specific antigen (PSA) screening, up to 60% of men diagnosed as having prostate cancer may not require therapy. 8 Results of the European Randomised Study of Screening for Prostate Cancer demonstrated a 20% mortality reduction attributable to screening and treatment; however, 48 additional men needed to be treated to prevent 1 prostate cancer death. 2 It is not currently possible to distinguish patients who require treatment to avoid For editorial comment see p 2411.

At least one co-author has disclosed a financial relationship of potential relevance for this res... more At least one co-author has disclosed a financial relationship of potential relevance for this research. Further information is available online at http://www.nber.org/papers/w23290.ack NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

Medical Care, 2014

Background: A number of instruments have been developed to measure health-related quality of life... more Background: A number of instruments have been developed to measure health-related quality of life (HRQoL), differing in the health domains covered and their scoring. Although few such measures have been consistently included in US national health surveys over time, the surveys have included data on a broad range of symptoms and impairments, which enables the tracking of population health trends. Objectives: To compare trends in HRQoL as measured using existing instruments versus using a broader range of symptoms and impairments collected in multiple years of nationally representative data. Data and Measures: Data were from the 2000-2010 Medical Expenditure Panel Survey, which is nationally representative of the noninstitutionalized US population. Level of and trends in HRQoL derived from a broad range of survey symptoms and impairments (SSI) was compared with HRQoL from the SF-6D, the HALex, and, between 2000 and 2003, the EuroQol-5D (EQ-5D) and EQ-5D Visual Analog Scale. Results: Trends in HRQoL were similar using different measures. The SSI scores correlated 0.66-0.80 with scores from other measures and mean SSI scores were between those of other measures. Scores from all HRQoL measures declined similarly with increasing age and with the presence of comorbid conditions. Conclusions: Measuring HRQoL using a broader range of symptoms and impairments than those in a single instrument yields population health trends similar to those from other measures while making maximum use of existing data and providing rich detail on the factors underlying change.

New England Journal of Medicine, 2009

Cancer, 2007

BACKGROUND. Lung cancer is the leading source of cancer mortality and spending. However, the valu... more BACKGROUND. Lung cancer is the leading source of cancer mortality and spending. However, the value of spending on the treatment of lung cancer has not been conclusively demonstrated. The authors evaluated the value of medical care between 1983 and 1997 for nonsmall cell lung cancer in the elderly US population. METHODS. The authors used Surveillance, Epidemiology, and End Results (SEER) data to calculate life expectancy after diagnosis over the period 1983 to 1997. Direct costs for nonsmall cell lung cancer detection and treatment were determined by using Part A and Part B reimbursements from the Continuous Medicare History Sample File (CMHSF) data. The CMHSF and SEER data were linked to calculate lifetime treatment costs over the time period of interest. RESULTS. Life expectancy improved minimally, with an average increase of approximately 0.60 months.

American Journal of Public Health, 2013

We decomposed QALE into changes in life expectancy, impairments, symptoms, and smoking and body m... more We decomposed QALE into changes in life expectancy, impairments, symptoms, and smoking and body mass index. Results. Years of QALE increased overall and for all demographic groupsmen, women, Whites, and Blacks-despite being slowed by increases in obesity and a rising prevalence of some symptoms and impairments. Overall QALE gains were large: 2.4 years at age 25 years and 1.7 years at age 65 years. Conclusions. Understanding and consistently tracking the drivers of QALE change is central to informed policymaking. Harmonizing data from multiple national surveys is an important step in building this infrastructure.

NBER working papers are circulated for discussion and comment purposes. They have not been peer-r... more NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

We are grateful to the National Institute on Aging (P01-AG031098 and R37AG047312) for research su... more We are grateful to the National Institute on Aging (P01-AG031098 and R37AG047312) for research support and to Barry Bosworth and seminar participants for helpful comments. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. At least one co-author has disclosed a financial relationship of potential relevance for this research. Further information is available online at http://www.nber.org/papers/w25233.ack NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

Urology, 2004

Objectives. The purposes of this study were to estimate the difference in quality-adjusted life-y... more Objectives. The purposes of this study were to estimate the difference in quality-adjusted life-years between conservative management and prostatectomy or radiotherapy (RT) by clinical Gleason score (2 to 4, 5 to 6, 7, and 8 to 10) for patients aged 55 years and older with clinically localized prostate cancer and to adjust for and explore the effects of lead-time. For localized prostate cancer, it is not known whether treatment (prostatectomy or RT) results in longer quality-adjusted survival than conservative management. Observed survival benefits after treatment may be biased by the lead-time resulting from early diagnosis with prostate-specific antigen screening. Methods. A Markov simulation was developed, and transition probabilities were derived from a review of published studies. Utility weights were measured in male volunteers older than 60 years. Estimates of disease progression during conservative management were adjusted for lead-time. Sensitivity analyses were performed on all parameters (including estimates for lead-time). Results. For Gleason score 2 to 4 cancer, conservative management yielded the greatest number of quality-adjusted life-years. For Gleason score 5 to 6 cancer, any of the options appeared beneficial, depending on the estimates for disease progression. For Gleason score 7 to 10 cancer, prostatectomy and RT resulted in more quality-adjusted life-years than conservative management; with a lead-time adjustment of greater than 10 years, the outcomes with conservative management and prostatectomy were similar. The choice between prostatectomy and RT was sensitive to estimates of disease progression after treatment. Conclusions. Conservative management is a reasonable option for Gleason score 2 to 4 cancer and for some patients with Gleason score 5 to 6 cancer. Prostatectomy or RT is recommended for Gleason score 7 to 10 cancer. The survival benefits after treatment were not explained by the lead-time alone. UROLOGY 63: 103-109, 2004.

The Journal of Urology, 2006

Background: Recruitment of patients into cancer research studies is exceedingly difficult, partic... more Background: Recruitment of patients into cancer research studies is exceedingly difficult, particularly for early phase trials. Payer reimbursement policies are a frequently cited barrier. We examined whether state policies that ensure coverage of routine medical care costs for cancer trial participants are associated with an increase in clinical trial enrollment. Methods: We used logistic Poisson regressions to analyze enrollment in National Cancer Institute phase II and phase III Clinical Trials Cooperative Group trials and compared changes in trial enrollment rates between 1996 and 2001 of privately insured cancer patients who resided in the four states that enacted coverage policies in 1999 with enrollment rates in states without such policies. All statistical tests were two-sided. Results: Trial enrollment rates increased in the coverage and noncoverage states by 24.9% (95% confidence interval [CI] ϭ 22.8% to 27.0%) and 28.8% (95% CI ϭ 27.7% to 29.8%) per year, respectively, from 1996 through 2001. After implementation of the coverage policies in 1999 in four states, there was a 21.7% (95% CI ϭ 3.8% to 42.6%) annual increase in phase II trial enrollment in coverage states, compared with a 15.6% (95% CI ϭ 8.8% to 21.8%) annual decrease in noncoverage states (P Ͻ .001). After accounting for secular trend, cancer type, and race in multivariable analyses, the odds ratio (OR) for a phase II trial participant residing in a coverage versus a noncoverage state after 1999 was 1.59 per year (95% CI ϭ 1.22 to 2.07; P ϭ.001). In a multivariable analysis of phase III trial participation, there was a decrease in the odds of residing in a coverage state after 1999 (OR ϭ 0.90, 95% CI ϭ 0.84 to 0.98; P ϭ .011). Conclusion: State coverage policies were associated with a statistically significant increase in phase II cancer trial participation and did not increase phase III cancer trial enrollment. Editorial Comment: Randomized clinical trials are the gold standard for determining the efficacy of cancer therapies. Unfortunately, less than 3% of adult patients with cancer participate in clinical research studies. Numerous factors hinder enrollment of eligible patients. In an attempt to improve access of patients to cancer trials 15 states have passed legislative mandates or entered into mutual agreements with large health plans to ensure reimbursement of routine medical costs for clinical trial participants. Unfortunately, these efforts have yielded mixed results. The legislation appears to have had a positive impact on phase II studies. These are the studies designed to test drug safety and appropriate dosing. However, the legislation does not appear to have increased enrollment in phase III studies. These studies are the definitive trials designed to test treatment efficacy. Encouraging increased participation in clinical studies appears to be a complex issue that requires considerably more public education.

While health care cost growth in the United States has slowed in the past few years (Hartman et a... more While health care cost growth in the United States has slowed in the past few years (Hartman et al. 2015), health costs are projected to grow faster than the economy over the next decade (Cutler and Sahni 2013; Sisko et al. 2014; Keehan et al. 2015) and are one of the biggest fi scal challenges to the nation. As such, policymakers and analysts regularly try to better understand the value of this spending, so as to target cost containment eff orts to curb excess-rather than essential-spending. Unfortunately, there is often a mismatch between the data that are available and what policymakers need. Current National Health Expenditure Accounts measure medical spending at the level of the payers (Medicare, Medicaid, private insurance, etc.) and recipient of funds (hospital, physicians' offi ce, pharmaceutical company, etc.). However, measuring the value of medical spending requires relating expenditures to the health outcomes

This paper is motivated by two facts. The first is the large and growing share of people who rece... more This paper is motivated by two facts. The first is the large and growing share of people who receive disability insurance for pain-related conditions. About 40% of older adults have chronic pain, and musculoskeletal conditions (including back and neck pain, arthritis, and related maladies) are the most common conditions leading people to enroll in Social Security Disability Insurance (SSDI; SSA 2015). The second fact is the enormous increase in availability of opioid medications in recent years. Figure 1 shows national shipments of pain-relieving medications, taken from the Drug Enforcement Administration's ARCOS records. The figure shows morphine milligram equivalents (MMEs) per adult per year; 1,400 milligrams is more than one 30-day prescription per adult per year. Between 2001 and 2010, shipments of pain relievers increased by a factor of nearly four. They have remained at that level since.

This paper is motivated by two facts. The first is the large and growing share of people who rece... more This paper is motivated by two facts. The first is the large and growing share of people who receive disability insurance for pain-related conditions. About 40% of older adults have chronic pain, and musculoskeletal conditions (including back and neck pain, arthritis, and related maladies) are the most common conditions leading people to enroll in Social Security Disability Insurance (SSDI; SSA 2015). The second fact is the enormous increase in availability of opioid medications in recent years. Figure 1 shows national shipments of pain-relieving medications, taken from the Drug Enforcement Administration's ARCOS records. The figure shows morphine milligram equivalents (MMEs) per adult per year; 1,400 milligrams is more than one 30-day prescription per adult per year. Between 2001 and 2010, shipments of pain relievers increased by a factor of nearly four. They have remained at that level since.

JAMA, 2010

N 2009, 192 000 MEN WERE DIAGnosed as having prostate cancer in the United States. Of these men, ... more N 2009, 192 000 MEN WERE DIAGnosed as having prostate cancer in the United States. Of these men, 70% will have been classified as having low-risk, clinically localized disease, and more than 90% will have undergone initial treatment. 1-4 Initial treatment choices include surgical resection or radiation therapy. The majority of men experience at least 1 adverse effect of treatment. 5-7 In the era of prostate-specific antigen (PSA) screening, up to 60% of men diagnosed as having prostate cancer may not require therapy. 8 Results of the European Randomised Study of Screening for Prostate Cancer demonstrated a 20% mortality reduction attributable to screening and treatment; however, 48 additional men needed to be treated to prevent 1 prostate cancer death. 2 It is not currently possible to distinguish patients who require treatment to avoid For editorial comment see p 2411.

At least one co-author has disclosed a financial relationship of potential relevance for this res... more At least one co-author has disclosed a financial relationship of potential relevance for this research. Further information is available online at http://www.nber.org/papers/w23290.ack NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

Medical Care, 2014

Background: A number of instruments have been developed to measure health-related quality of life... more Background: A number of instruments have been developed to measure health-related quality of life (HRQoL), differing in the health domains covered and their scoring. Although few such measures have been consistently included in US national health surveys over time, the surveys have included data on a broad range of symptoms and impairments, which enables the tracking of population health trends. Objectives: To compare trends in HRQoL as measured using existing instruments versus using a broader range of symptoms and impairments collected in multiple years of nationally representative data. Data and Measures: Data were from the 2000-2010 Medical Expenditure Panel Survey, which is nationally representative of the noninstitutionalized US population. Level of and trends in HRQoL derived from a broad range of survey symptoms and impairments (SSI) was compared with HRQoL from the SF-6D, the HALex, and, between 2000 and 2003, the EuroQol-5D (EQ-5D) and EQ-5D Visual Analog Scale. Results: Trends in HRQoL were similar using different measures. The SSI scores correlated 0.66-0.80 with scores from other measures and mean SSI scores were between those of other measures. Scores from all HRQoL measures declined similarly with increasing age and with the presence of comorbid conditions. Conclusions: Measuring HRQoL using a broader range of symptoms and impairments than those in a single instrument yields population health trends similar to those from other measures while making maximum use of existing data and providing rich detail on the factors underlying change.

New England Journal of Medicine, 2009

Cancer, 2007

BACKGROUND. Lung cancer is the leading source of cancer mortality and spending. However, the valu... more BACKGROUND. Lung cancer is the leading source of cancer mortality and spending. However, the value of spending on the treatment of lung cancer has not been conclusively demonstrated. The authors evaluated the value of medical care between 1983 and 1997 for nonsmall cell lung cancer in the elderly US population. METHODS. The authors used Surveillance, Epidemiology, and End Results (SEER) data to calculate life expectancy after diagnosis over the period 1983 to 1997. Direct costs for nonsmall cell lung cancer detection and treatment were determined by using Part A and Part B reimbursements from the Continuous Medicare History Sample File (CMHSF) data. The CMHSF and SEER data were linked to calculate lifetime treatment costs over the time period of interest. RESULTS. Life expectancy improved minimally, with an average increase of approximately 0.60 months.

American Journal of Public Health, 2013

We decomposed QALE into changes in life expectancy, impairments, symptoms, and smoking and body m... more We decomposed QALE into changes in life expectancy, impairments, symptoms, and smoking and body mass index. Results. Years of QALE increased overall and for all demographic groupsmen, women, Whites, and Blacks-despite being slowed by increases in obesity and a rising prevalence of some symptoms and impairments. Overall QALE gains were large: 2.4 years at age 25 years and 1.7 years at age 65 years. Conclusions. Understanding and consistently tracking the drivers of QALE change is central to informed policymaking. Harmonizing data from multiple national surveys is an important step in building this infrastructure.

NBER working papers are circulated for discussion and comment purposes. They have not been peer-r... more NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

We are grateful to the National Institute on Aging (P01-AG031098 and R37AG047312) for research su... more We are grateful to the National Institute on Aging (P01-AG031098 and R37AG047312) for research support and to Barry Bosworth and seminar participants for helpful comments. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. At least one co-author has disclosed a financial relationship of potential relevance for this research. Further information is available online at http://www.nber.org/papers/w25233.ack NBER working papers are circulated for discussion and comment purposes. They have not been peer-reviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.