The Quality of Managed Care: Evidence from the Medical Literature
Gottfried, Joseph, Sloan, Frank A., Law and Contemporary Problems
The past decade has seen a proliferation of state laws aimed at modifying the function of managed care organizations ("MCOs"). (1) Reaction to the increasing prevalence and novel practices of MCOs has prompted passage of hundreds of state statutes governing everything from direct access to medical specialists, to minimum coverage standards for maternity stays. (2) The federal government has also taken action on such matters, and the competing "patients' bills of rights" under consideration in Congress would all expand federal oversight of managed care activities. (3) Though the true impetus for these legal initiatives is debatable, the proponents of "patient protection" measures often cite concern over the quality--or safety--of managed care as the driving force behind their legislative efforts. (4) Critics contend that MCOs sacrifice high-quality health care for cost savings and provide inferior medical coverage compared to fee-for-service ("FFS") plans. (5) Horror stories about alleged abuse or neglect of p atients by MCOs have gained wide circulation. (6) There are even web sites devoted to the promulgation of such anecdotal evidence. (7) Opponents of managed care have employed these singular tales of terror to advance their legislative agendas. (8)
This article examines the empirical evidence, drawn from the medical literature, pertaining to the safety of managed care practices. It seeks to ground the ongoing debate on the medical merits of MCOs in the science of clinical research. The article is divided into three major sections. Part II is a systematic review of recent literature on the overall quality of MCOs relative to FFS plans, focusing on clinically important outcome and process measures. It extends previous such analyses to the present day. Part III surveys articles comparing the performance of generalists and specialists in the latter's fields of expertise. It aims to weigh claims about the alleged risks of "gatekeeping," a traditional feature of managed care that has come under increasing criticism. Part IV analyzes the medical evidence on early postpartum discharge ("drive-through deliveries"), perhaps the most publicized example of the supposed dangers of managed care. Though originating in FFS settings, this practice is associated with MCO s due to their widespread adoption of short maternal stays. Finally, the article renders an evidence-based opinion on the quality of America's major form of private health care coverage.
QUALITY-OF-CARE PERFORMANCE: MANAGED CARE VERSUS FEE-FOR-SERVICE
Considerable data on the quality of care in MCOs versus FFS does exist even though it is conspicuously absent from public debates on the safety of managed care and the need for more patient protection laws in the post-FFS era. Robert Miller and Harold Luft have reviewed much of the early research on this subject, and in 1994 published the first of two literature analyses on the topic. (9) Examining studies from 1980 through 1993, the investigators found that MCO members were more likely than FFS plan enrollees to receive recommended preventive health services. (10) They also reported that treatment processes and outcomes for a wide range of medical conditions were roughly comparable between the two types of coverage. In 1997, the authors completed a second narrative review on the subject. (11) Considering studies published since their previous analysis, they concluded that available evidence suggested essentially equivalent quality of care between MCOs and FFS plans. (12) They cautioned, however, that almost none of the papers in their review included primary data past 1992, when cost cutting by MCOs began in earnest. (13)
In a recent examination of Miller and Luft's methods, Kip Sullivan criticized their analyses for failing to control for differences in the level of coverage between insurance plans. (14) He argued that it is misleading to compare "FES patients who are insured but have inferior coverage (e.g., no coverage for drugs and cancer screens) ... with [MCO] patients who have superior coverage (e.g., coverage for drugs and cancer screens)." (15) He proposed to exclude from systematic review those articles failing to adjust their results for differences in coverage levels offered by competing plans. (16 )Sullivan correctly called attention to the nature of the "variables" under investigation in individual studies--a point that will be pursued later in this paper with regard to the expansive meaning of "fee-for-service." His ultimate proposal, however, seems misguided. MCOs may well be superior to indemnity insurance precisely because of financial incentives for preventive health care or access to a cheaper formulary. In health service research, such distinctive features of systems of care are presumed to account for differences in research outcomes, and as such represent the focus of investigation. They are not confounding factors that require statistical adjustment.
For the present paper, we conducted a systematic review of the recent medical literature on the quality-of-care performance of MCOs versus FFS plans. Our main goal was to capture studies based on primary data collected since 1992, which, as Miller and Luft suggested, may be more relevant than earlier evidence for understanding current managed care. We sought articles that examined differences in the rates of medical processes (such as provision of proven preventive measures, recommended medications, or indicated procedures) or outcomes (such as mortality or morbidity from disease). (17) Studies were included only if they: (1) were published in peer-reviewed journals; (2) were not cited in Miller and Luft's 1997 analysis; (3) concerned the American health care system; (4) examined either processes or outcomes (excluding patient satisfaction); and (5) had reasonable comparison groups. (18) Each of the final thirty-three studies--including twenty-three retrospective and seven prospective cohort studies, in addit ion to two surveys and one cross-sectional analysis--was evaluated for its quality of evidence based on the guidelines formulated by David Naylor and Gordon Guyatt. (19)
The thirty-three articles are presented in Tables 1-5, grouped by condition or disease (cardiovascular disease, cancer, geriatrics, pregnancy/pediatrics, and miscellaneous). The tables list the types of coverage compared in each study, as well as its data sources and the variables included in the authors' multivariate analysis (if performed). Before considering the studies as a whole, we discuss the major findings from each group of articles separately.
A. Cardiovascular Disease
It is not surprising that the largest group of studies looked at cardiovascular disease, the most common cause of mortality in America (Table 1). Five of the articles examined elements in the management of acute myocardial infarction ("AMI"). (20) Steven Soumerai and his colleagues tested the hypothesis that elderly AMI patients in health maintenance organizations ("HMOs") may suffer as a result of delayed approval of the use of ambulances and emergency services. (21) They found that times to treatment, EKG, and thrombolytic therapy were almost identical for Medicare beneficiaries enrolled in HMOs and FFS plans. (22) HMO patients were more likely to receive aspirin. (23) Dr. Mark Sada and his colleagues reported that people in non-Medicare MCO and FFS plans had similar post-AMI mortality at short-term follow-up, though FFS patients more often underwent indicated coronary angiography than MCO enrollees. (24) Edward Guadagnoli and his colleagues also found that FFS bested MCOs in the rate of indicated angiograp hy after AMI in their study of Medicare beneficiaries. (25) In articles on use of recommended medications after hospitalization for AMI, Dr. Danny McCormick and his colleagues reported equal rates of receipt of aspirin and beta-blockers by non-Medicare patients in FFS and MCOs, (26) while Mary Seddon and her colleagues published similar findings for a Medicare population. (27)
Two studies compared the use of higher-quality (lower-mortality) hospitals by FFS and MCO patients for coronary artery bypass graft surgery ("CABG"). Jose Escarce and Mark Pauly observed greater use of such facilities by non-Medicare LIMO enrollees in California, but not in Florida. (28) Medicare FFS patients in Florida, however, were more often admitted to better hospitals than Medicare HMO members. (29) Dr. Lars Erickson and his colleagues found that people with FFS were more likely than LIMO enrollees to receive CABG at a lower-mortality hospital in New York State. (30) This was true for both Medicare and non-Medicare populations. (31) Dr. Nathan Every and his colleagues studied the treatment of unstable angina, and found that people with managed care more often received guideline-recommended medications than those with indemnity insurance. (32) They observed no difference between these two groups in the rates of in-hospital AMI or death. (33)
In sum, MCOs appear to deliver equal or better medical care to cardiac patients relative to FES, but equal or possibly worse invasive care (angiography or CABG). As to the latter circumstance, Erickson and his colleagues hypothesized that "[f]inancial risk provides a strong incentive for health plans to select low-priced hospitals," even when available data on quality militate against the use of such facilities (for example, for CABG). (34) Dr. Sada and his colleagues suggested that the "aggressive cost-containment measures ... found in many HMOs," which should have "their most pronounced effect on discretionary procedures," may also influence payment for nondiscretionary interventions (for example, indicated coronary angiography). (35) Given the attention paid to invasive procedures such as bypass and catheterization, it is worth noting that perhaps the single most important intervention in cardiology is the provision of an aspirin to a patient with a suspected AMI, which is associated with a 23% relative re duction--and a 2.4% absolute reduction--in the rate of cardiovascular death at five weeks. (36) The finding by Soumerai and his colleagues that HMO members were more likely than their FFS counterparts to receive aspirin for AMI (37) seems at least as important as Erickson's discovery of these patients' differential use of lower-mortality hospitals for CABG in New York State. (38)
Studies of cancer treatment and outcomes comprised the next largest group of articles, in keeping with the disease's public health importance (Table 2). Three papers focused on breast cancer. Arnold Potosky and his colleagues reported significantly higher survival for Medicare HMO than Medicare FFS breast cancer patients in California (though not in Washington State). (39) HMO enrollees in both California and Washington State with early-stage disease were more likely to receive breast-conserving surgery ("BCS") with adjuvant radiotherapy. (40) Gerald Riley and his colleagues, in a similar study by some of the same authors, found that members of Medicare HMOs were less often diagnosed with late-stage breast cancer than their FFS counterparts, and were more likely to receive post-BCS radiotherapy. (41) In a rare study that distinguished between precise types of Medicare coverage (supplemental indemnity, group model HMO, non-group model HMO, and others), Anna Lee-Feldstein and her colleagues observed no signific ant differences between HMO and indemnity breast cancer cases in terms of stage at diagnosis, use of UCS with adjuvant radiotherapy, or mortality. (42) HMOs were in fact superior to FFS when the latter was defined to include Medicare and Medicare/Medicaid in addition to private supplemental insurance (a definition employed by Potosky and his colleagues, among others). (43)
Results of studies on colorectal cancer were mixed. Ray Merrill and his colleagues reported lower all-cause mortality--as well as increased use of recommended radiotherapy--for Medicare HMO colorectal cancer patients compared to FFS cases in California and Washington State. (44) Cancer mortality was similar between the two groups. Richard Roetzheim and his colleagues, however, in a smaller study from Florida drawing on similar sources of data, found that non-Medicare FFS patients had lower all-cause mortality than their MCO counterparts, perhaps due to increased receipt of chemotherapy. (45) Medicare plans differed inconsistently in their use of chemotherapy and radiation.
Two additional articles concentrated on genitourinary cancer. Considering data from a single institution in Arizona, Dr. Stephanie Chin and Dr. Keith Harrigill reported no significant difference in the time to definitive surgical therapy for 193 FFS and MCO patients with gynecologic malignancies. (46) Potosky and his colleagues found that Medicare FFS prostate cancer patients had better cause-specific survival than HMO cases, though the two groups had similar rates of all-cause mortality. (47)
Overall, MCOs (specifically HMOs) appear to offer cancer patients equal or better rates of high-quality care and long-term survival than FFS. Yet most of the evidence for this conclusion comes from studies by one group of investigators working with data from two states, California and Washington. Although the researchers used accurate and comprehensive outcome measures, sensible comparison groups, and multivariate analysis (following large numbers of patients for extended periods of time), their articles are subject to criticism on the grounds of limited external validity. In each of their papers, Potosky (48) and Merrill (49) (though not Riley (50)) restricted their managed care sample to members of two of the oldest and best-established HMOs in the country. (51) It could be argued that these benchmark organizations on the West Coast are not representative of the relatively immature managed care market characteristic of most of the country. Still, it would be perverse to claim that managed care is worse than FFS in treating cancer patients when the best available evidence supports the opposite conclusion.
Six important articles (52) explicitly examined outcomes for the elderly, a group that may be particularly vulnerable to the possible restrictions of managed care (Table 3). (53) Sheldon Retchin and his colleagues reported no significant difference in the survival rates of elderly stroke patients in Medicare MCO and FFS plans. (54) William Getchell and his colleagues found better survival for elderly individuals hospitalized for syncope (fainting) who belonged to a group-model HMO. (55) Andrew Kramer and his colleagues conducted a cohort study of 429 older stroke victims. (56) They observed better short-term recovery of function among FES than HMO enrollees, which they attributed to intensive therapy received at rehabilitation hospitals. (57) People with FES plans were also more likely than HMO members to reside in the community at one year, despite the fact that both groups of patients demonstrated equal recovery of function by this point in time. (58)
In another prospective study, Bettina Experton and her colleagues found that "frail" elderly Medicare beneficiaries were more likely to be readmitted to the hospital--including for "preventable" reasons--if they belonged to a network model HMO rather than a supplemental indemnity plan. (59) Jeremy Holtzman and his colleagues followed 211 elderly patients discharged from the hospital after admissions for stroke, congestive heart failure, chronic obstructive pulmonary disease ("COPD"), or hip fracture. (60) People with Medicare managed care and FFS did not differ significantly in their physical functioning or rates of hospital readmission over the course of one year. (61) Finally, Frank Porell and Helen Miltiades reported lower mortality rates among moderately disabled Medicare beneficiaries with supplemental insurance than among their counterparts with capitated care. (62) Their study, which drew from survey data, found no difference in the annual odds of disablement among the two groups of patients. (63)
In general, "frail" or disabled elderly appear to do marginally better in FFS than MCO settings. Investigators have proposed various explanations for this observation. Kramer and his colleagues discussed the financial incentive for MCOs to discharge disabled patients to subacute facilities rather than costlier rehabilitation hospitals, as well as the significant cost savings associated with long-term nursing home placement of frail elders (which may still be less socially desirable than continued community residence). (64) Experton and her colleagues alluded to "[c]ontractual financial incentives and disincentives" in HMOs that may lead to inappropriately short hospital stays for seniors as well as the withholding of necessary home health care. (65) Retchin and his colleagues suggested that "subtle declines" in physical or mental function as a result of "fewer [MCO] services in acute care and post-acute care settings" may eventually take their toll on the elderly. (66) Whatever the reason, the differences in outcomes for seniors--though slight--seem real.
D. Pregnancy and Pediatric Disease
Six articles examined processes and outcomes for pregnancy and pediatric disease (Table 4). Michael Klinkman and his …
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Publication information: Article title: The Quality of Managed Care: Evidence from the Medical Literature. Contributors: Gottfried, Joseph - Author, Sloan, Frank A. - Author. Journal title: Law and Contemporary Problems. Volume: 65. Issue: 4 Publication date: Autumn 2002. Page number: 103+. © 2009 Duke University, School of Law. COPYRIGHT 2002 Gale Group.
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