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Medical Effectiveness/Outcomes Research

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Most outcomes of type-II diabetic and hypertensive patients are unrelated to system of care or physician specialty

The tendency of health maintenance organizations (HMOs) to use fewer medical resources and physician specialists compared with traditional fee-for-service (FFS) medicine has caused concern that this managed care approach could translate into worse health outcomes for patients. However, this concern appears to be unwarranted for patients with non-insulin-dependent diabetes mellitus (NIDDM) or hypertension. These patients have similar outcomes whether they are treated by generalist physicians or specialists (cardiologists or endocrinologists) and whether they are cared for in an FFS or prepaid managed care setting.

These findings are striking, given the tripled enrollment of Americans in HMOs in the past 10 years and the historically higher costs of FFS medicine and specialty practice, notes Sheldon Greenfield, M.D., of Tufts University Medical School, who led the study, which was supported by the Agency for Health Care Policy and Research (HS06665). Dr. Greenfield and his colleagues compared the outcomes of patients with hypertension or NIDDM at 2 years and 4 years and calculated their 7-year mortality rate. Patients in Boston, Chicago, and Los Angeles were drawn from three different systems of care (FFS patients; prepaid patients in solo or small single-specialty groups or in large multispecialty group practices; and patients in staff-model HMOs).

The researchers found that no one system of care or physician specialty achieved consistently better 2-year and 4-year outcomes or lower death rates for these patients. The one notable exception was the better foot-ulcer and infection outcomes for NIDDM patients (who are prone to infections of the extremities) treated by endocrinologists.

For more information, see "Outcomes of patients with hypertension and non-insulin-dependent diabetes mellitus treated by different systems and specialties," by Dr. Greenfield, William Rogers, Ph.D., Maureen Mangotich, M.D., M.P.H., and others, in the November 8, 1995, Journal of the American Medical Association 274(18), pp. 1436-1444.

Heart disease patients in America achieve better functioning than their Canadian counterparts

American heart attack patients undergo coronary diagnostic and revascularization procedures at twice the rate of Canadian patients, but they have equal rates of death and recurrent heart attacks. Yet Americans experience better functional status following heart attack (for example, less activity-limiting angina) than Canadians. This difference in functional status may be due to different patterns of managing heart disease in the two countries, according to a study supported in part by the Agency for Health Care Policy and Research (HS06503 and the Cardiac Arrhythmia Patient Outcomes Research Team [PORT-II], HS08362).

Led by Mark A. Hlatky, M.D., F.A.C.C., of the Stanford University School of Medicine, the researchers measured quality of life in patients enrolled in seven American and one Canadian site in the Bypass Angioplasty Revascularization Investigation. This multicenter, randomized clinical trial involved patients with multivessel coronary disease.

Results showed that the 350 American and Canadian patients without symptoms of heart disease prior to study enrollment had a similar quality of life. However, of the 860 patients with previous symptoms of heart disease, 27 percent of Americans vs. 16 percent of Canadians rated their health excellent. Americans had higher overall health and functional status scores but similar emotional and social health scores. These findings suggest that the lower functional status of Canadian patients with a previous history of heart disease or after heart attack is more likely to be due to differences in medical care in the two countries than to differences in nonmedical factors such as climate or culture.

More details are in "Better functional status in American than Canadian patients with heart disease: An effect of medical care?" by Louise Pilote, M.D., M.P.H., Martial G. Bourassa, M.D., F.A.C.C., Constance Bacon, Ed.M., and others, in the Journal of the American College of Cardiology 26(5), pp. 1115-1120, 1995.

Recent findings from the low birthweight PORT

The Patient Outcomes Research Team (PORT) on Low Birthweight in Minority and High-Risk Women, supported by the Agency for Health Care Policy and Research (contract 282-92-0055), examines ways to prevent low birthweight (LBW) and improve the outcomes of LBW infants. Led by Robert L. Goldenberg, M.D., of the University of Alabama at Birmingham, PORT researchers recently published findings on the importance of family planning in preventing low birthweight and the impact of magnesium sulfate on labor duration and cesarean-section (c-section) rates.

Klerman, L.V., Phelan, S.T., Poole, V.L., and Goldenberg, R.L. (1995). "Family planning: An essential component of prenatal care." Journal of the American Medical Women's Association 50(5),pp. 147-151.

Proper spacing of pregnancies and delay or prevention of pregnancy among women at high risk for poor birth outcomes could lower the rate of LBW infants, according to a recent review of the literature by Low Birthweight PORT researchers. One report of single births, in which the prior pregnancy ended with the birth of a live infant, found a relative risk for LBW of 1.63 for whites and 1.46 for blacks when the interval until the next pregnancy was less than 6 months. The effect of interval on birthweight remained after controlling for age, birth order, race, marital status, and educational level. The link between unintended conceptions and LBW is probably related to inadequate prenatal care (counseling, family planning) during the previous pregnancy, smoking, alcohol use, and inadequate weight gain, note the researchers. In one study, the LBW rate for both well-timed and mistimed (too early) pregnancies was 5 percent, and for unwanted births it was 8.8 percent. About 24 percent of births to smoking women were unwanted compared with 11 percent of births to nonsmoking women. The relationship between unintended pregnancies and behaviors associated with increased risk of LBW suggests that family planning might prevent some cases of LBW by reducing the rate of unintended pregnancies, conclude the researchers.

Atkinson, M.W., Guinn, D., Owen, J., and Hauth, J.C. (1995). "Does magnesium sulfate affect the length of labor induction in women with pregnancy-associated hypertension?" American Journal of Obstetrics & Gynecology 173(4), pp. 1219-1222.

For women with pregnancy-associated hypertension, use of magnesium sulfate (compared with phenytoin) to prevent hypertension-related seizures does not prolong the induction of labor, nor does it result in an increase in c-section deliveries, according to members of the Low Birthweight PORT. This is contrary to the common impression among clinicians. The researchers studied women with a single pregnancy in vertex presentation between 32 and 42 weeks gestation who required labor induction for hypertension-related problems. Fifty-four women with similar characteristics were randomized to receive either magnesium sulfate or phenytoin (Dilantin) to prevent seizures. The interval from labor induction to delivery and the rate of c-sections were similar in both groups. Neonatal outcomes also were similar in both groups, and no women had seizures.

Prostate PORT examines costs and effectiveness of prostate cancer screening among elderly men

The Prostate Patient Outcomes Research Team (PORT-II) was funded by the Agency for Health Care Policy and Research (HS08397) to assess therapies for localized prostate cancer and benign prostatic hyperplasia (BPH). The researchers, led by Michael J. Barry, M.D., of Harvard Medical School, recently published a series of four papers that discuss whether or not Medicare should reimburse physicians for prostate-specific antigen (PSA) testing for early detection of prostate cancer. The American Cancer Society recommends that men 50 years of age and older have this test annually. The first paper in the series was summarized in the November/December 1995 issue of Research Activities. The other three papers are discussed here.

Coley, C.M., Barry, M.J., Fleming, C., and others (1995). "Should Medicare provide reimbursement for prostate-specific antigen testing for early detection of prostate cancer? Part II: Early detection strategies." Urology 46(2), pp. 125-141.

In this paper, the Prostate PORT-II researchers describe and discuss the benefits and drawbacks of commonly used tests for early detection of prostate cancer, including digital rectal examination (DRE), PSA measurement, transrectal ultrasound (TRUS), and transrectal needle biopsy of the prostate (TRNB). The researchers point out that age has a complex effect on the results of screening for prostate cancer. For example, the specificity of PSA, and probably DRE as well, deteriorates as more men in the population have greater amounts of BPH.

Barry, M.J., Fleming, C., Coley, C.M., and others (1995). "Should Medicare provide reimbursement for prostate-specific antigen testing for early detection of prostate cancer? Part III: Management strategies and outcomes." Urology 46(3), pp. 277-289.

In a review of management strategies, members of the Prostate PORT-II discuss the controversy surrounding the optimal treatment for clinically localized prostate cancer. In the United States, the preference is for aggressive treatment, with urologists generally preferring radical prostatectomy. In recent years there has been considerable regional variation in the use of this procedure, whose risks include perioperative death, medical complications, long-term incontinence and impotence, and urethral stricture disease. The researchers also discuss strategies to determine the stage of prostate cancer, including surgery, and the risks and benefits of expectant management (watchful waiting), a commonly used strategy for clinically localized cancer worldwide. Finally, they review issues surrounding the followup treatment after curative therapy, such as radiation or androgen deprivation therapy.

Barry, M.J., Fleming, C., Coley, C.M., and others (1995). "Should Medicare provide reimbursement for prostate-specific antigen testing for early detection of prostate cancer? Part IV:Estimating the risks and benefits of an early detection program." Urology 46(4), pp. 445-461.

In this paper, the Prostate PORT-II researchers estimate the risks, benefits, and costs of an early prostate cancer detection program among older men. They outline several assumptions they use to model health outcomes of early detection of prostate cancer for men ages 65 to 75 years. They detail the expected harm and maximal benefit of DRE and PSA screening cohorts of 100,000 men at 65, 70, and 75 years of age for prostate cancer. Based on their assumptions and data, 28-40 percent of Medicare-age men who are screened would have suspicious results on DRE and PSA testing. This proportion is very high compared with other common screening tests, such as mammography for breast cancer screening (up to 6 percent), fecal occult blood testing for colorectal cancer screening (2 to 5 percent), or Papanicolaou smears for cervical cancer screening (1 to 13 percent). The researchers present estimated costs and discounted benefits, in terms of life-years and days saved per person screened, given certain cost assumptions favoring early detection and treatment. They conclude that it is premature to offer a Medicare benefit for PSA testing for early detection of prostate cancer when a legitimate question can be raised about whether such screening does more harm than good.

Clinical characteristics combined with a patient's report of visual functioning predict degree of improvement following cataract surgery

Physicians and their patients who have cataracts may be able to predict which patients will have improved visual function following cataract surgery, according to a study supported in part by the Agency for Health Care Policy and Research (National Research Service Award fellowship F32 HS00048). The study shows that younger age, poorer preoperative visual function, posterior subcapsular cataract, absence of age-related macular degeneration, and/or diabetes can predict the probability of substantial improvement following cataract surgery.

Carol M. Mangione, M.D., M.S.P.H., of Brigham and Womens Hospital, and her colleagues developed a predictive model based on these five characteristics. To develop the model, they studied visual function preoperatively and at 3 and 12 months after cataract surgery in 424 patients to find out which characteristics influenced visual function outcomes. They measured improvement in visual function using the Activities of Daily Vision Scale (ADVS), which includes such activities as day and night driving, reading, and sewing.

Using their model, they classified 145 patients into three groups with probabilities of substantial improvement in visual function of 85 percent, 34 percent, and 3 percent. They conclude that preoperative clinical characteristics can be combined with a standardized patient report of visual functioning to predict which patients have the greatest probability of improving in common visual activities after surgery.

For more information, see "Prediction of visual function after cataract surgery," by Dr. Mangione, E. John Orav, Ph.D., Mary G. Lawrence, M.D., and others, which appears in the October 1995 Archives of Ophthalmology 111, pp. 1305-1311.

Cataract PORT publishes recent findings

Cataracts are the second leading cause of blindness in the United States. Nearly one out of five persons 65-74 years of age (18 percent) and almost half (46 percent) of those aged 75-84 years have cataracts that impair their everyday activities and ability to live independently. The Cataract Patient Outcomes Research Team (PORT) was funded by the Agency for Health Care Policy and Research (HS06280) to study variations in cataract management, patient outcomes, and the economic aspects of cataract treatment.

PORT researchers, led by Earl P. Steinberg, M.D., M.P.P., of The Johns Hopkins University, recently published the results of three studies, discussed below. They examine physician use of preoperative tests for healthy cataract patients, patient expectations vs. outcomes of cataract surgery, and the impact of second-eye vs. first-eye cataract surgery on visual acuity, function, and patient satisfaction.

Bass, E.B., Steinberg, E.P., Luthra, R., and others (1995). "Do ophthalmologists, anesthesiologists, and internists agree about preoperative testing in healthy patients undergoing cataract surgery?" Archives of Ophthalmology 113, pp. 1248-1256.

A 1991 national survey of ophthalmologists, anesthesiologists, and internists shows that these physicians varied from each other and within their own specialty in their reported use of preoperative medical tests for healthy cataract patients and in their reasons for using these tests. For example, 50 percent of ophthalmologists, 40 percent of internists, and 33 percent of anesthesiologists frequently or always obtained a chest x-ray film, while 20 percent, 27 percent, and 37 percent, respectively, never obtained a chest x-ray film for these patients. Similarly, 70 to 90 percent of ophthalmologists, 73 to 79 percent of internists, and 41 to 79 percent of anesthesiologists frequently or always obtained a complete blood cell count, electrolyte panel, and electrocardiogram, while 4 to 11 percent, 13 to 17 percent, and 9 to 28 percent, respectively, never obtained these tests. Moreover, many of the physicians believed that some tests were unnecessary but performed them for reasons ranging from medicolegal concerns to institutional requirements.

Tielsch, J.M., Steinberg, E.P., Cassard, S.D., and others. (1995). "Preoperative functional expectations and postoperative outcomes among patients undergoing first eye cataract surgery." Archives of Ophthalmology 113, pp. 1312-1318.

For this study, Cataract PORT researchers recruited 772 patients undergoing first-eye cataract surgery from 75 ophthalmology practices in three urban areas. The patients in this study had high expectations of improved visual functioning after cataract surgery, and in most cases, their expectations were fulfilled. About 61 percent of patients achieved or surpassed their expected level of postoperative functioning. However, patients older than 75 years or with coexisting visual problems experienced a larger gap between expected and actual postoperative function than patients who were younger or had no coexisting visual problems. The researchers suggest that, in selected cases, more comprehensive counseling may reduce the discrepancy between expected and actual outcomes of cataract surgery.

Javitt, J.C., Steinberg, E.P., Sharkey, P., and others (1995). "Cataract surgery in one eye or both?" Ophthalmology 102(11), pp. 1583-1593.

In a study of the same group of patients described above, the Cataract PORT researchers showed that the 36 percent of patients who underwent cataract extraction in the second affected eye during the 1-year study period had 61 percent greater improvement in their visual function, 27 percent less trouble with vision, and 24 percent greater improvement in satisfaction with their vision compared with those who underwent surgery in only one eye. At 12 months after first-eye surgery, patients who had undergone surgery in both eyes demonstrated a 1.6-fold greater improvement in visual function, were 2.1 times as likely to report no trouble with their vision, and were 2.7 times more likely to be satisfied with their vision than patients who had only one cataract removed. The improvement was greater in older patients and those with worse vision in their second eye prior to surgery. These findings support the AHCPR Cataract Guideline Panel's recommendation that the main indication for cataract surgery in the second eye should be the same as that for surgery in the first eye—namely, impairment in the patient's ability to function in everyday life due to his or her vision.

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