Objective: To examine whether there are differential impacts of patient cost sharing and health plan organizational characteristics on the use of a recommended cancer screening service (mammography) versus a controversial cancer screening service (prostate cancer screening [PCS]).
Study Design: Observational cohort using the 1996 Medical Expenditure Panel Survey.
Patients and Methods: A nationally representative sample of privately insured individuals was examined. Outcome measures were the receipt of mammography and PCS. Logistic regression was used to assess the impact of patient cost sharing and health plan organizational characteristics on the receipt of mammography and PCS, controlling for other covariates.
Results: Patient cost sharing and gatekeeper requirements were strong predictors of PCS but were statistically insignificant predictors of mammography. Men in health plans with a copayment over $10 (odds ratio [OR] = 0.38, 95% confidence interval [CI] = 0.19- 0.78) or with deductibles over $250 (OR = 0.38, 95% CI = 0.23- 0.62) were significantly less likely to receive PCS than men in plans with no or lower copayments and deductibles. Men in gatekeeper plans were less likely to receive PCS than those without gatekeepers (OR = 0.48, 95% CI = 0.29-0.81).
Conclusions: We found the impact of cost sharing on utilization is different between mammography and PCS. Prostate cancer screening utilization appears to respond to financial incentives while mammography utilization does not. The use of copayments, deductibles, and gatekeepers may discourage controversial services but may not have an adverse effect on more recommended services. These findings have implications for the design of insurance benefits and plan organizational structure.
(Am J Manag Care. 2004;10(part 1):99-107)
It has long been recognized that health insurance reduces the effective price of medical
services that patients face and may thereby result in overutilization of services. An increasing number of
health insurers have adopted patient cost sharing mechanisms to curb utilization and to control the rising
costs of healthcare. Numerous studies have attempted to assess the impact of such cost sharing strategies
on the use of a wide range of medical services, including physician visits and hospital admissions,
office-based medical care, mental health services, emergency department use, preventive care, vision care,
dental care, and chiropractic services.1-12 Findings from the RAND studies and others based on
community data are generally consistent with economic theory predicting that patient cost sharing reduces
the use of medical services.
Although earlier research has improved our knowledge of whether and to what extent cost
sharing influences the use of health services, it is also important to evaluate whether its effect differs
for the use of recommended versus controversial medical services. A meaningful inquiry is how
patient cost sharing influences the use of healthcare: does cost sharing improve consumption efficiency by
reducing the use of inappropriate services or does it create another dimension of distortion by reducing
the use of appropriate services?
Despite its importance, literature on this topic is very limited. Only a few studies have
examined whether the influence of cost sharing differs for the use of appropriate and inappropriate care.
Siu et al analyzed data from the RAND Health Insurance Experiment (HIE) to determine whether cost sharing
disproportionately reduces inappropriate hospital admissions and hospital stay.13 These authors
found that cost sharing decreased both inappropriate, as well as appropriate hospital use. Foxman and
colleagues, also using the data from the RAND HIE, found that the impact of cost sharing on inappropriate
and appropriate antibiotic use was similar.14
Rather than analyzing the appropriate and inappropriate use of services, the objective of
this study was to examine whether there is a differential impact of cost sharing on the use of recommended
and controversial cancer screening services. We used data from the 1996 Medical Expenditure Panel Survey
(MEPS) to analyze mammography and prostate cancer screening (PCS) utilization. Mammography is a widely
recommended screening test because of substantial evidence that it is associated with reduced breast cancer
mortality.15 In contrast, PCS is more controversial, with no consensus about its efficacy or
recommendations.15,16 The analysis of mammography and PCS provides an interesting comparison as
to whether the impact of cost sharing differs between recommended and controversial cancer preventive
services. We hypothesized that patients (and possibly providers) would be more cost conscious in their
decisions to use (or encourage) controversial services as compared with recommended services. Our study
adds to the literature by extending this line of research to preventive services and by updating the
empirical evidence using a more recent dataset that approximates today's healthcare environment.
This study also contributes to the literature on cancer screening utilization by examining
the association between a comprehensive set of health plan characteristics. Most of the other studies that
have investigated the association between plan characteristics and cancer screening have used broad
categories of insurance (eg, managed care vs fee-for-service plans or health maintenance organizations
(HMOs) vs non-HMOs).17-19 More recent studies have shown that the distinctions between these
broad plan classifications are blurring and what may be most important predictors are specific
characteristics of the plan.20-22 In this study, we examine several specific plan
characteristics, including patient cost sharing (eg, copayments, deductibles, and coinsurance rates), as
well as organizational characteristics such as having a defined provider network and requirements for the
use of gatekeepers.
Our study provides interesting empirical evidence on how cost sharing influences the use
of preventive care and has policy implications for practice and insurance benefit design. To our knowledge
this is the first study to analyze the association between cost sharing and PCS utilization. It is also the
first to investigate whether there is a differential impact of cost sharing on the use of 1 strongly
recommended screening service versus a more controversial cancer screening procedure.
The primary data source for this study was from the 1996 MEPS-Household Component (HC).
MEPS is an ongoing survey sponsored by the Agency for Healthcare Research and Quality and is designed to
provide nationally representative data on the demographic characteristics, health status, healthcare use,
access to care and insurance status of the US civilian, noninstitutionalized population.23 The
Health Insurance Plan Abstraction (HIPA) component of the 1996 MEPS contains detailed information on the
private insurance plans obtained from health plan booklets. Despite its age, the potential to analyze
detailed health insurance data collected directly from plan documentation linked to individual
characteristics and healthcare utilization information makes the 1996 MEPS data the most comprehensive data
currently available for the purposes of this study.
The secondary data used for this analysis included the 1995 National Health Interview
Survey (NHIS). Individuals' physician visit information in 1995 was linked to 1996 MEPS to allow us to
examine the association between physician visits and the use of cancer screening procedures over a 2-year
period. The linkage between these 2 datasets is made possible because the 1996 MEPS sample is drawn from a
subset of respondents to the 1995 NHIS.
Our study sample included privately insured adults from the MEPS-HC who were linked to
HIPA (unweighted, n = 13 534).
We examined a widely recommended preventive service, mammography, and a more controversial
preventive service, PCS. In 1996, the US Preventive Services Task Force (USPSTF) strongly recommended
routine screening for breast cancer with mammography every 1-2 years for women between the ages of 50-69,
and suggested that screening for women aged 70-75 may be reasonable because of high burden of suffering
from breast cancer despite limited evidence supporting screening for this age group. Most concur that
screening mammography every 1-2 years in women aged 50 and over can reduce breast cancer
mortality.24 We therefore examined the self-reported receipt of mammography screening within the
past 2 years for women aged 50 and older, without a prior history of breast cancer.
Routine screening for prostate cancer is not recommended by the USPSTF. Other
organizations, however, recommend prostate cancer screening, including the American Cancer Society, the
American Urological Association, and others. These organizations suggest that men without a family history
of prostate cancer undergo an annual prostate specific antigen screening over the age of 50.24-26
We examined the self-reported receipt of prostate cancer screening within the past 2 years for men
ages 50 and older, without a prior history of prostate cancer.
Predictors of mammography and PCS examined in this study include characteristics of
patients, providers, and health plans. The primary independent variables of interest for this study were
patient cost sharing and organizational characteristics of a health plan (Table 1). Since a number
of patient and provider characteristics have already been identified in the literature as being associated
with the utilization of cancer screening services, they are controlled for in our model as well. Patient
cost sharing measures included in our model were copayment, deductible, and coinsurance. Health plan
organizational characteristics included measures of a defined provider network, gatekeeper requirements,
and the use of cost-containment procedures. The measures of patient cost sharing and cost containment
strategies were based on health plan booklet data. Information on provider network and gatekeeper
requirements was available through both plan booklets and self-report data. Measures from both
self-reported and plan documentation for network and gatekeeping requirements were used because perceptions
of plan characteristics may have more influence on the behavior of healthcare utilization than the actual
plan characteristics. 27