Grant Details
Grant Number: |
5R01CA074760-02 Interpret this number |
Primary Investigator: |
Garber, Alan |
Organization: |
National Bureau Of Economic Research |
Project Title: |
Economics of Cancer |
Fiscal Year: |
1998 |
Abstract
DESCRIPTION: The purpose of the proposed study is to: 1) Assess the
validity of claims data for estimating incidence, treatment, expenditures
and outcomes for lung, colon and prostate cancer in the elderly; 2) Analyze
trends in screening, initial therapy, followup monitoring and treatment of
recurrences for these cancers; 3) Measure the effects of policy factors,
including types of cancer facilities, state laws and competitive pressures;
4) Estimate the effects of these alternative treatment patterns on costs and
outcomes of care; and 5) Develop comprehensive simulation models from the
empirical findings to estimate the consequences of policy and treatment
changes affecting the management of cancer in the U.S.
The first objective addresses a National Cancer Institute Program
Announcement, "Cancer Surveillance Using Health Claims-Based Data Systems".
These research questions will be examined using a large, national data base
and instrumental variable (IV) techniques to control for omitted variables
bias. The analysis is in three parts. The first part focuses on the
reliability of Medicare claims data for epidemiologic and economic research
on cancer. The second analysis focuses on trends in medical treatment
patterns, expenditures and outcomes, and the policy and demographic factors
influencing those trends. The third part of the analysis uses instrumental
variables (i.e., variables that are correlated with choice of treatment, but
uncorrelated with unobserved factors affecting health outcomes, such as
patient health status) to identify the marginal effect of treatments on
outcomes.
The investigators have reduced the number of cancers to be studied from six
to three: lung, prostate and colon cancer. Stage of cancer at diagnosis is
divided into two basic categories: localized and metastatic. Cancer
treatment is divided into four phases: detection, initial therapy, followup
surveillance for patients with localized cancers and later treatment likely
associated with recurrence. Treatments are limited to: invasive screening
procedures (for prostate and colon cancer), degree of aggressive surgical
management and the use of a broader range of aggressive measures (surgery,
chemotherapy and/or radiation therapy). The principal outcome measures will
be survival time and treatment-free survival months (months without a
hospitalization or a cancer treatment). Expenditure measures will include
total insured reimbursement (and patient deductibles and copayments) and
estimated costs. (Table 8 on page 42 summarizes the operational definition
of variables in the analysis.)
The proposed analytic methods build on the investigators' approach to
analysis of the effectiveness of cardiac catheterization. Because patients
are not assigned randomly to treatments, the investigators are concerned
that omitted variables, such as unobserved dimensions of patient health,
might influence both treatment choice and patient outcomes. Their approach
is to identify a variable, such as access to facilities that offer
particular treatment technologies, to stand in as an "instrument" for actual
treatment in the analysis. If access to treatment is correlated with choice
of treatment, but not with unobserved measures of patient health, then
comparing treatment outcomes for patients with different levels of access
can provide an unbiased estimate of the effect of different treatments on
outcomes.
Publications
None