Prevalence of Parkinson's disease-induced psychosis in a large U.S. managed care population.

Using 10 years' enrollment history, patients with non-drug-induced Parkinson's disease were identified, and the prevalence of Parkinson's disease-induced psychosis (PDP) was estimated using three different claims algorithms based on an expert working group criteria. The estimated prevalence of PDP ranged from 4 to 45/1,000 Parkinson's disease patients. PDP patients were just as likely to be male as female and were significantly older than Parkinson's disease patients without PDP. PDP patients more commonly had evidence of dementia and use of atypical antipsychotics. PDP occurs in up to 45,000 Parkinson's disease patients in the United States but represents a unique neuropsychiatric finding with important treatment implications.

A clinically detailed risk information system for cost.

The authors discuss a system that describes the resources needed to treat different subgroups of the population under age 65, based on burden of disease. It is based on 173 conditions, each with up to 3 severity levels, and contains models that combine prospective diagnoses with retrospectively determined elements. We used data from four different payers and standardized the cost of most services. Analyses showed that the models are replicable, are reasonably accurate, explain costs across payers, and reduce rewards for biased selection. A prospective model with additional payments for birth episodes and for serious problems in newborns would be an effective risk adjuster for Medicaid programs.

A performance-based quality evaluation system for preferred provider organizations.

This article describes a performance-based quality evaluation program developed by a partnership of insurers for a nationwide preferred provider organization (PPO) which uses indicators to monitor for practice deviations from PPO standards representing four components of patient care--administrative efficiency, patient satisfaction, medical practice standards, and clinical outcome. Quality improvement efforts to eliminate deviant practices through indirect organizational strategies and direct communication with preferred physicians are also described. The program's strengths are its effective use of available data, its potential application to other organizations with a loosely connected network of providers, and its ability to simultaneously monitor care received over time by individual patients in various settings (hospitals, physician offices).

Quality of ambulatory care. Epidemiology and comparison by insurance status and income.

In this report the data from medical history questionnaires, screening examinations, insurance claims, and a face-to-face physician interview were used to examine the quality of ambulatory care received for 17 chronic conditions by a general population of 5986 adults (less than or equal to 65) and children (less than or equal to 14) enrolled in the RAND Health Insurance Experiment. Subjects in six U.S. sites were randomly assigned to insurance plans that were free or that required cost sharing, or in one site to an HMO. Quality-of-care criteria--both process (what was done to patients) and outcome (what happened to them)--were developed. Overall, 81% of outcome criteria and 62% of process criteria were met. Physicians interviewed patients with selected conditions at the Experiment's end to evaluate care. They suggested that approximately 70% of patients should have their current therapy changed, but only 30% of patients would obtain more than minor improvement from such a change. Clinically meaningful plan differences in quality of care were observed only for the process criteria dealing with the need for a visit (free plan compliance 59%; cost sharing compliance 52%). Quality of care for the poor was slightly worse than for the nonpoor and persons randomized to an HMO had slightly better overall quality of care than those in the fee-for-service system. Substantial improvements in the quality of the process of care could be made, but impact on outcome may be small. Results of the analysis suggest the need for development of clinical models to test the relationship between specific process criteria and improvements in outcome.

Prepaid group practice effects on the utilization of medical services and health outcomes for children: results from a controlled trial.

A total of 693 children between the ages of 0 and 13 years were randomly assigned to either a staff model HMO or to one of several fee-for-service insurance plans in Seattle to evaluate differences in medical expenditures and health outcomes. Although the fee-for-service plans varied the amount of cost sharing (0% to 95%), all children were covered for the same medical services, for either 3 or 5 years. No differences in imputed total expenditures were observed for children assigned to the HMO or any of the fee-for-service plans. Children with cost-sharing fee-for-service plans, however, had fewer medical contacts and received fewer preventive services than those assigned to the HMO. Nonetheless, children with the cost-sharing fee-for-service plans were perceived (by their mothers) to be in better health overall than those assigned to the HMO. No significant differences regarding physiological outcomes (eg, visual acuity, hemoglobin level) were observed between the two groups. The results of this experiment neither strongly support nor indict fee-for-service or prepaid care for children.

Providing primary general medical care in university hospitals: efficiency and cost.

Data on efficiency, costs, and profits of 15 internal medicine outpatient group practices in university hospitals were collected for 9 months from interviews, a time-motion study, observations, and reviews of bills. Charges for a follow-up visit were about 25% higher than Medicare's allowable charges, but differed threefold across practices. Physicians spent more than half their allocated patient care or supervision time in other activities and 14% of nursing time was used for direct patient care. Visits to second- and third-year residents cost one half of those to faculty. Faculty supervision of second- and third-year residents was limited; it was, on average, 2 minutes per follow-up visit. Despite these inefficiencies, bad debts, and educational costs, practices appeared to break even financially. We conclude it is financially feasible for university hospitals to provide primary care to disadvantaged populations.

Effects of cost sharing on physiological health, health practices, and worry.

In a randomized trial of the effects of medical insurance on spending and the health status of the nonaged, we previously reported that patients with limited cost sharing had approximately one-third less use of medical services, similar general self-assessed health, and worse blood pressure, functional far vision, and dental health than those with free care. Of the 20 additional measures of physiological health studied here on 3,565 adults, people with cost sharing scored better on 12 measures and significantly worse only for functional near vision. People with cost sharing had less worry and pain from physiological conditions on 33 of 44 comparisons. There were no significant differences between plans in nine health practices, but those with cost sharing fared worse on three types of cancer screening and better on weight, exercise, and drinking. Overall, except for patients with hypertension or vision problems, the effects of cost sharing on health were minor.

Preventive care: do we practice what we preach?

We used insurance claims from enrollees in the Rand Health Insurance Experiment to determine the amount of selected components of preventive care received by a representative sample of the non-aged population in the United States and to determine whether insurance coverage was an important determinant of that amount. Only 45 percent of infants received timely immunization for DPT and polio; 93 per cent received some well child care by 18 months of age. In the three-year experimental period, only 4 per cent of adults had a tetanus shot, 66 per cent of women aged 17-44 and 57 per cent aged 45-65 received a Pap smear, and 2 per cent of women aged 45-65 had a mammogram. Cost sharing was associated with even less preventive care: 60 per cent of children on the free plan and 49 per cent on cost sharing plans received preventive care of any type. For adults, women on the free plan received more preventive care of several kinds, and those aged 45-65 received more Pap smears than those on cost-sharing plans. Even with free care, most enrollees did not receive adequate preventive care. Thus, free care alone, while significant, is not a sufficient incentive to providing recommended levels of preventive care. The average per person insurance charge for increasing the amount of preventive care to a level consistent with that recommended would be $22 for a complete set of immunizations by age 18 months, $9 for a Pap smear every three years, and $97 for a Pap test and mammogram every three years.

Effect of a health maintenance organization on physiologic health. Results from a randomized trial.

In a previous comparison of persons between 14 and 62 years of age randomly assigned to receive care through a fee-for-service system (n = 784) or through a health maintenance organization (HMO) (n = 738) in Seattle, Washington, persons in the HMO had much lower hospital expenditures and admissions, more bed days, a higher prevalence of serious symptoms, and less satisfaction with care. We report an examination of 20 additional health status measures. Our results are consistent with a hypothesis of no differences in health status measures between the two systems. In addition, a comparison of nine health practices between the systems also indicated no overall differences. Most physiologic measures and health practices for a typical person were not affected by care received through the fee-for-service system or the HMO. However, we are less certain of this result in specific subgroups, such as persons of lower income initially at elevated risk, because confidence intervals are necessarily wider. We conclude that the cost savings achieved by this HMO through lower hospitalization rates were not reflected in lower levels of health status.

The effect of cost sharing on the use of antibiotics in ambulatory care: results from a population-based randomized controlled trial.

Little is known about how generosity of insurance and population characteristics affect quantity or appropriateness of antibiotic use. Using insurance claims for antibiotics from 5765 non-elderly people who lived in six sites in the United States and were randomly assigned to insurance plans varying by level of cost-sharing, we describe how antibiotic use varies by insurance plan, diagnosis and health status, geographic area, and demographic characteristics. People with free medical care used 85% more antibiotics than those required to pay some portion of their medical bills (controlling for all other variables). Antibiotic use was significantly more common among women, the very young, patients with poorer health, and persons with higher income. Use of antibiotics for viral, viral-bacterial, and bacterial conditions did not differ between free and cost-sharing insurance plans, given antibiotics were the treatment of choice. Cost sharing reduced inappropriate and appropriate antibiotic use to a similar degree.

Inappropriate use of hospitals in a randomized trial of health insurance plans.

We examined geographic variation in the rate of inappropriate hospitalization and the effect of cost sharing on that rate. The medical records of 1132 adults hospitalized in a randomized trial of health insurance plans were reviewed by two physicians who were blinded to the patients' insurance plan. They judged 23 percent of the admissions to be inappropriate and an additional 17 percent to have been avoidable by the use of ambulatory surgery. The percentage of inappropriate admissions varied among six sites (from 10 to 35 percent), but areas with low total admission rates did not necessarily have low proportions of inappropriate admissions. In plans with cost sharing for all services, 22 percent of admissions and 34 percent of hospital days were classified as inappropriate, as compared with 24 percent of admissions and 35 percent of hospital days in the plan under which care was free to the patient (these differences were not statistically significant). Our data show that a substantial fraction of hospitalization is potentially avoidable. Because cost sharing did not selectively reduce inappropriate hospitalization, it is important to develop other mechanisms to do so.

Chronic disease in a general adult population. Findings from the Rand Health Insurance Experiment.

Using questionnaire and physical screening examination data for a general population of 4,962 adults aged 18 to 61 years enrolled in the Rand Health Insurance Experiment, we calculated the prevalence of 13 chronic illnesses and assessed disease impact. Low-income men had a significantly higher prevalence of anemia, chronic airway disease and hearing impairment than their high-income counterparts, low-income women a higher prevalence of congestive heart failure, diabetes mellitus, hypertension, hearing impairment and vision impairment. Of our sample, 30% had one chronic condition and 16% had two or more. Several significant pairs or "clusters" of chronic illnesses were found. With few exceptions (diabetes, hypertension), the use of physician care in the previous year for a specific condition tended to be low. Disease impact (worry, activity restriction) was widespread but mild. Persons with angina, congestive heart failure, mild chronic joint disorders and peptic ulcer disease reported a greater impact than persons with other illnesses.

Comparison of health outcomes at a health maintenance organisation with those of fee-for-service care.

To determine whether health outcomes in a health maintenance organisation (HMO) differed from those in the fee-for-service (FFS) system, 1673 individuals ages 14 to 61 were randomly assigned to one HMO or to an FFS insurance plan in Seattle, Washington for 3 or 5 years. For non-poor individuals assigned to the HMO who were initially in good health there were no adverse effects. Health outcomes in the two systems of care differed for high and low income individuals who began the experiment with health problems. For the high income initially sick group, the HMO produced significant improvements in cholesterol levels and in general health ratings by comparison with free FFS care. The low income initially sick group assigned to the HMO reported significantly more bed-days per year due to poor health and more serious symptoms than those assigned free FFS care, and a greater risk of dying by comparison with pay FFS plans.

How free care reduced hypertension in the health insurance experiment.

In a controlled trial of the effects of medical insurance on spending and health status, we previously reported lower average (0.8 mm Hg) diastolic blood pressures with free care than with cost-sharing plans. We show herein that for clinically defined hypertensives, blood pressures with free care were significantly lower (1.9 mm Hg) than with cost-sharing plans, with a larger difference for low-income hypertensives than for high-income hypertensives (3.5 vs 1.1 mm Hg), but similar differences for blacks and whites. The cause of the difference was the additional contact with physicians under free care; this led to better detection and treatment of hypertensives not under care at the start of the study. Free care also led to higher compliance by hypertensives with diet and smoking recommendations and higher use of medication by those who needed it.

Consequences of cost-sharing for children's health.

Do children whose families bear a percentage of their health care costs reduce their use of ambulatory care compared with those families who receive free care? If so, does the reduction affect their health? To answer these questions, 1,844 children aged 0 to 13 years were randomly assigned (for a period of 3 or 5 years) to one of 14 insurance plans. The plans differed in the percentage of their medical bills that families paid. One plan provided free care. The others required up to 95% coinsurance subject to a +1,000 maximum. Children whose families paid a percentage of costs reduced use by up to one third. For the typical child in the study, this reduction caused no significant difference in either parental perceptions of their child's health or in physiologic measures of health. Confidence intervals are sufficiently narrow for most measures to rule out the possibility that large true differences went undetected. Nor were statistically significant differences observed for children at risk of disease. Wider confidence intervals for these comparisons, however, mean that clinically meaningful differences, if present, could have been undetected in certain subgroups.