There are many reasons why people do not adhere to prescribed regimens for medications and other treatments, including costs, side effects, and inconvenience.1–3 From a health policy perspective, perhaps the most concerning of these for seniors is cost. If beneficiaries underuse medications and other treatments that might improve their health because of cost, then it is important to understand the magnitude of this problem and to identify potential remedies. The recent passage of the Medicare Modernization Act will reduce out-of-pocket medication costs for some seniors, but for many others, out-of-pocket costs are likely to remain a serious problem. Furthermore, little is known about the impact of other factors such as health status, HMO membership, and physician-patient relationship quality on cost-related underuse.
Most previous work has focused on cost-related underuse of medications. It is clear that Medicare beneficiaries who do not have prescription drug coverage use fewer medications than those who do have coverage,4–9 and to that cost-related underuse of medications is associated with worse health outcomes.10,11 Furthermore, recent work shows that cost-related medication underuse is common among adults with chronic illness.12 However, only 3 papers that we are aware of directly examine the problem of cost-related medication skipping in seniors.10,13,14 Neither of these studies were longitudinal nor were they designed to understand whether physician-patient relationship quality or HMO membership was associated with underuse of medications or other treatments.
To fill in these gaps, we analyzed data from The Study of Choice and Quality in Senior Health Care, a longitudinal study of Medicare beneficiaries aged 65 and older in 13 states.15 We surveyed beneficiaries in both traditional Medicare and Medicare HMOs in 1998 and 2000. Our analyses had 3 goals: (1) to provide estimates of the rate of cost-related skipping of medications and other treatments in these 13 states, (2) to determine sociodemographic and clinical characteristics associated with skipping, and (3) to determine whether the rate of skipping increased between 1998 and 2000, and if so, why.
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There were 3 main findings from this work. First, cost-related skipping of medications and other treatments is relatively common, and increasing. Second, increases in out-of-pocket medication costs and HMO membership explained most of the increase in cost-related skipping between 1998 and 2000. Third, better physician-patient relationship quality is associated with less cost-related skipping.
The mean rates of cost-related skipping of medications and other treatments were 9.5% in 1998 and 13.1% in 2000. These average figures conceal strikingly high rates of skipping in high-risk subgroups. Using our models, the estimated skipping rate for a 65 year old with MCS and PCS of 40, no prescription drug coverage, out-of-pocket costs of >$50 per month, low income, and a poor physician-patient relationship was 81%. It is difficult to compare our cost-related skipping rates with those of other, contemporaneous studies of patients over 65 because of differences in item content and sampling, but our rates were similar to others. We previously reported data from a 2001 study in which cost-related mediation nonadherence rates varied from 7% to 41% depending on the survey item used and the patient subgroup assessed.13 Steinman et al. assessed cost-related medication skipping in 1995–1996 and found a rate of 8%,14 and Mojtabai and Olfson found a rate of 7% using data from 2000. 10 More importantly, this is the first study we are aware of that assessed cost-related underuse longitudinally, and we document a 38% 2-year increase.
Prescription drug costs rose at a rate that far exceeded the Consumer Price Index between 1998 and 2000,26–29 which probably explains why the strongest correlate of the increase in cost-related skipping between 1998 and 2000 was rising out-of-pocket drug costs. But, in addition, we observed an increase in odds of skipping for patients with out-of-pocket costs greater than $25. The aggregate impact of increased out-of-pocket costs on cost-related skipping is the product of these two factors. The increase in the OR for out-of-pocket costs may be because many of these patients have fixed incomes. Up to a certain point, they may pay for increases in out-of-pocket drug costs out of savings or other assets. But once a cost threshold is reached, drug costs may compete directly with other necessities like food and utilities.
The HMO finding was unexpected, and may be a selection effect. HMO members in this analysis had lower incomes than those in traditional Medicare ($3,072 less in 1998 and $3,876 less in 2000), and probably differed in other ways as well. They may have enrolled in an HMO because of the drug benefit. Changes in HMO prescription drug policies between 1998 and 2000—including fewer offering a pharmacy benefit, drug caps, use of formularies, and increasing copays30—may have resulted in increased cost-related skipping for low-income beneficiaries. Coverage arrangements for other treatments (e.g., physical therapy) may have increased in HMOs during these years, but any such changes would likely have been dwarfed in magnitude by changes in drug costs.30 Further studies of cost-related medication skipping and HMO membership are needed.
Recent data from several other studies suggest that physician-patient communication about prescription medication costs is suboptimal.31,32 Our findings, for the first time, directly link physician-patient relationship quality to cost-related skipping of medications and other treatments. Better physician-patient communication may help patients make more informed spending decisions or reveal lower cost medication options. Our findings suggest that physicians discuss cost-related underuse of medications and other therapies with all their patients.
There are several study limitations. First, we do not know whether our findings generalize to states where Medicare HMOs were less well established. Second, because vulnerable subgroups of seniors, such as minorities and those with low income, are underrepresented here because of higher rates of nonresponse and loss to follow-up, our results may understate rates of cost-related skipping. Third, self-selection of seniors into traditional Medicare versus HMOs may bias system comparisons if important differences between the populations are not captured by the study design and analytic methods. Fourth, self-reported medication skipping of medications and other therapies may underestimate actual skipping. Fifth, we could not separate rates of medication skipping from rates of skipping of other therapies. However, we believe that most of the skipping that we are capturing with the survey item we used is medication related. Over 90% of beneficiaries use prescription medications, whereas only 10% use outpatient therapy services,33 and out-of-pocket medication costs were a strong correlate of cost-related skipping.
As important as the new prescription drug benefit embodied by the Medicare Modernization Act may be for seniors, we show that cost-related skipping of medications and other treatments is associated with several different factors, including poverty and poor health. If a prescription drug plan requires significant cost sharing, certain vulnerable subgroups will almost certainly continue to experience relatively high cost-related medication skipping rates, particularly low-income seniors whose income or assets may not qualify for any low-income subsidies because their income or assets make them ineligible.13 An important new finding from this research is that better physician-patient relationships are independently associated with less cost-related skipping. We believe that physicians should initiate discussions about out-of-pocket costs, prescription drug coverage, and cost-related underuse of medications and other therapies with all of their patients. In some cases, it will be possible to substitute high-cost medications with equally effective, lower-cost alternatives.34