Showing papers by "RAND Corporation published in 1994"

Development of the Kidney Disease Quality of Life (KDQOL) Instrument

Abstract: This paper describes the Kidney Disease Quality of Life (KDQOLTM) Instrument (dialysis version), a self-report measure that includes a 36-item health survey as the generic core, supplemented with multi-item scales targeted at particular concerns of individuals with kidney disease and on dialysis (symptom/problems, effects of kidney disease on daily life, burden of kidney disease, cognitive function, work status, sexual function, quality of social interaction, sleep). Also included were multi-item measures of social support, dialysis staff encouragement and patient satisfaction, and a single-item overall rating of health. The KDQOLTM was administered to 165 individuals with kidney disease (52% female; 48% male; 47% White; 27% African-American; 11% Hispanic; 8% Asian; 4% Native American; and 3% other ethnicities), sampled from nine different outpatient dialysis centres located in Southern California, the Northwest, and the Midwest. The average age of the sample was 53 years (range from 22 to 87), and 10% were 75 years or older. Internal consistency reliability estimates for the 19 multi-item scales exceeded 0.75 for every measure except one. The mean scores for individuals in this sample on the 36-item health scales were lower than the general population by one-quarter (emotional well-being) to a full standard deviation (physical function, role limitations due to physical health, general health), but similar to scores for dialysis patients in other studies. Correlations of the KDQOLTM scales with number of hospital days in the last 6 months were statistically significant (p<0.05) for 14 of the 19 scales and number of medications currently being taken for nine of the scales. Results of this study provide support for the reliability and validity of the KDQOLTM.

The Clementine Mission to the Moon: Scientific Overview

Abstract: In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity.

Eliciting Student Expectations of the Returns to Schooling

Abstract: We report here on the design and first application of an interactive computer-administered personal interview (CAPI) survey eliciting from high school students and college undergraduates their expectations of the income they would earn if they were to complete different levels of schooling We also elicit respondents' beliefs about current earnings distributions Whereas a scattering of earlier studies have elicited point expectations of earnings unconditional on future schooling, we elicit subjective earnings distributions under alternative scenarios for future earnings We find that respondents, even ones as young as high school sophomores, are willing and able to respond meaningfully to questions eliciting their earnings expectations in probabilistic form Respondents vary considerably in their earnings expectations but there is a common belief that the returns to a college education are positive and that earnings rise between ages 30 and 40 There is a common belief that one's own future earnings are rather uncertain Moreover, respondents tend to overestimate the current degree of earnings inequality in American society

Health care for black and poor hospitalized Medicare patients.

Abstract: Objective. —To analyze whether elderly patients who are black or from poor neighborhoods receive worse hospital care than other patients, taking account of hospital effects and using validated measures of quality of care. Design. —We compare quality of care provided to insured, hospitalized Medicare patients who are black or live in poor neighborhoods as compared with others, using simple and multivariable comparisons of clinically detailed measures of sickness at admission, quality, and outcomes. Setting. —Two hundred ninety-seven acute care hospitals in 30 areas within five states. Patients or Other Participants. —The sample includes a nationally representative sample of 9932 patients 65 years of age or older who lived at home prior to hospitalization for congestive heart failure, acute myocardial infarction, pneumonia, or stroke. Interventions. —This was an observational study. Main Outcome Measures. —Processes of care, length of stay, instability at discharge, discharge destination, and mortality. Results. —Within rural, urban nonteaching, and urban teaching hospitals, patients who are black or from poor neighborhoods have worse processes of care and greater instability at discharge than other patients (P Conclusions. —Quality of hospital care for insured Medicare patients is influenced both by the patient's race and financial characteristics and by the hospital type in which the patient receives care. (JAMA. 1994;271:1169-1174)

How Economic Development and Family Planning Programs Combined to Reduce Indonesian Fertility

Abstract: This paper examines the contributions of family planning programs, economic development, and women’s status to Indonesian fertility decline from 1982 to 1987. Methodologically we unify seemingly conflicting demographic and economic frameworks into a single “structural” proximate-cause model as well as controlling statistically for the targeted (nonrandom) placement of family planning program inputs. The results are consistent with both frameworks: 75% of the fertility decline resulted from increased contraceptive use, but was induced primarily through economic development and improved education and economic opportunities for females. Even so, the dramatic impact of the changes in demand-side factors (education and economic development) on contraceptive use was possible only because there already existed a highly responsive contraceptive supply delivery system.

Use of minor tranquilizers and antidepressant medications by depressed outpatients : results from the medical outcomes study

Abstract: Objective The purpose of this study was to compare use of minor tranquilizers and antidepressant medications by depressed outpatients across different treatment settings. Method The study subjects were 634 patients with current depressive disorder or depressive symptoms who visited general medical clinicians, psychiatrists, psychologists, or other therapists. Data on use of medication in different types of clinical practices with different types of payment plans were gathered from structured interviews by study clinicians and from surveys of patients. Results Of the depressed patients, 23% had recently used an antidepressant medication and 30% had used a minor tranquilizer. The level of use was similar for different types of depression. Patients of psychiatrists were the most likely to use medications. In the practices of physicians, but not nonphysicians, the more severely distressed patients were more likely to use antidepressant medications. Of the patients taking an antidepressant medication, 39% used an inappropriately low dose. Patients in prepaid health care plans were twice as likely as those in fee-for-service care to use minor tranquilizers. Conclusions Less than one-third of the depressed outpatients used antidepressant medications, and the probability of use was similar for major depression and other types of depression for which efficacy is less well established. Use of antidepressant medications among patients of nonphysicians was unrelated to the level of psychological sickness, suggesting the need for more cooperation among provider groups. Minor tranquilizers were used more often than antidepressants, particularly among patients in prepaid plans, despite controversy over their efficacy.

Subthreshold depression and depressive disorder : clinical characteristics of general medical and mental health specialty outpatients

Abstract: Objective: The authors examined the clinicalsignificance ofdepressive symptoms below the threshold for depressive disorder in outpatient samples. Method: The subjects were 775 adult patients with current depressive disorder, 1,420 patients with subthreshold depression, and 1,767 hypertensive patients with and without depression, all ofwhom were visiting the offices of mental health specialists and general medical care providers in three U.S. cities. Data on demographic characteristics, severity ofdepression, extent ofpsychiatric and medical comorbidity, family psychiatric history, and treatment history for the patients with depressive disorder and those with subthreshold depression were compared. Results: The percentage of patients with subthreshold depression who had a family history of depression (41 %) was nearly as high as that of the patients with depressive disorder (59%). The two groups of patients had similar levels ofmedicalandpsychiatric comorbidity except for anxiety disorders, which were greater among the patients with depressive disorder. Among the hypertensive patients in the general medical sector, those with subthreshold depression were more similar to those with depressive disorder than to the nondepressed hypertensive patients. Treatment rates were considerably lower for patients with subthreshold depression than for patients with depressive disorder in the general medical sector, but they were similar in the mental health specialty sector. Conclusions: In these outpatients, subthreshold depression appeared to be a variant ofaffective disorder and was treated as such in the mental health specialty sector but not in the generalmedicalsector. The findings emphasize the importance oftreatment outcome studies ofpatients with subthreshold depression. (Am J Psychiatry 1994; 151:1777-1784)

Management of heart failure. III. The role of revascularization in the treatment of patients with moderate or severe left ventricular systolic dysfunction.

Abstract: Objective. —This article reviews the benefits and risks of coronary artery bypass grafting and angioplasty for patients with moderate or severe left ventricular systolic dysfunction and summarizes the recommendations of the expert panel for the Agency for Health Care Policy and Research Heart Failure Guideline. Data Sources. —Data were obtained from studies published in English and referenced in MEDLINE or EMBASE between 1966 and 1993. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure ; and dilated cardiomyopathy in conjunction with the terms coronary artery bypass grafting and angioplasty . Study Selection. —All cohort studies and case series that provided separate outcomes data on a subgroup of patients with a left ventricular ejection fraction less than 0.40 were reviewed. Data Extraction and Synthesis. —Studies were reviewed for inclusion and exclusion criteria, survival, and functional status measures using a standardized form. Cohort studies were assessed on eight aspects of study quality using a defined list of study flaws. Conclusion. —Coronary artery bypass grafting improves 3-year survival by approximately 30% to 50% and physical functioning by approximately one New York Heart Association class in patients with moderate to severe left ventricular dysfunction and limiting angina. However, the operative mortality ranges from 5% to 30% depending on patients' ejection fractions and comorbidity. It is not clear whether patients whose predominant symptom is heart failure rather than angina benefit from bypass surgery or how much ischemia is required to justify surgical intervention. Clinical outcomes after angioplasty have not been adequately studied to determine the relative risks and benefits compared with bypass grafting. ( JAMA . 1994;272:1528-1534)

The impact of patient adherence on health outcomes for patients with chronic disease in the Medical Outcomes Study.

Abstract: The association between adherence to medical recommendations and health outcomes (physical, role, and social functioning, energy/fatigue, pain, emotional well-being, general health perceptions, diastolic blood pressure, and glycohemoglobin) was examined in a 4-year longitudinal, observational study of 2125 adult patients with chronic medical conditions (hypertension, diabetes, recent myocardial infarction, congestive heart failure) and/or depression. Change score models were evaluated, controlling for disease and comorbidity. Patient adherence was associated minimally with improvement in health outcomes in this study. Only 11 of 132 comparisons showed statistically significant positive effects of adherence on health outcomes. We conclude that the relationship between adherence and health outcomes is much more complex than has often been assumed.

Four-year cross-lagged associations between physical and mental health in the Medical Outcomes Study.

Abstract: This article provides an application of structural equation modeling to the evaluation of cross-lagged panel models. Self-reports of physical and mental health at 3 different time points spanning a 4-year interval were analyzed to illustrate the cross-lagged analysis methodology. Data were collected from a sample of 856 patients with hypertension, diabetes, heart disease, or depression (or any combination of these) participating in the Medical Outcomes Study. Cross-lagged analyses of physical and mental health constructs revealed substantial stability effects across time. A structural model with standard effects revealed positive effects of physical health on mental health but negative (suppression) effects of mental health on physical health. The effects of mental health on physical health became nonsignificant when the model was revised by adding nonstandard effects (direct effects of measured variable residuals on latent variables). Recommendations for structural equation modeling of cross-lagged panel data are provided.

Simultaneous determination of mercury speciation in biological materials by GC/CVAFS after ethylation and room-temperature precollection.

Abstract: We developed a method for the simultaneous determination of monomethyl mercury (MMHg), inorganic mercury [Hg(II)], and total mercury (THg) in biological materials. A variety of biological materials can be digested in methanolic KOH solution. The MMHg and Hg(II) present are converted to volatile ethyl derivatives, methylethyl mercury and diethyl mercury, by an aqueous-phase ethylation reaction with sodium tetraethylborate. The ethyl derivatives are precollected onto a trapping column at room temperature, in case of disconnection with the separation/detection system, and then thermally desorbed into a packed isothermal gas chromatography (GC) column. Eluted organo-Hg compounds from the GC column are decomposed into Hg0, and detection is completed by cold vapor atomic fluorescence spectrometry (CVAFS). Pure standard solutions can be used for calibration. The sum of MMHg and Hg(II) obtained by this method equals the THg value obtained by digestion with HNO3 and H2SO4, reduction with SnCl2, and single-stage amalgamation/CVAFS for all biological materials studied. Absolute detection limits are 0.6 pg and 1.3 pg of Hg as MMHg and Hg(II), respectively, corresponding to 0.3 ng and 0.6 ng/g (wet) of sample.

Living arrangements of older Malaysians : who coresides with their adult children?

Abstract: More than two-thirds of Malaysians age 60 or older coreside with an adult child. Data from the Senior sample of the Second Malaysian Family Life Survey (MFLS-2) are used to investigate which "seniors" (persons age 60 or older) live in this way. The analysis generally supports the notion that coresidence is influenced by the benefits, costs, opportunities, and preferences for coresidence versus separate living arrangements. For example, married seniors are more likely to coreside with adult children when housing costs are greater in their area or when the husband or wife is in poor health. This finding suggests that married parents and children live together to economize on living costs or to receive help with household services. Unmarried seniors who are better off economically are less likely to live with adult children, presumably because they use their higher incomes to "purchase privacy."

Quality of life of epilepsy surgery patients as compared with outpatients with hypertension, diabetes, heart disease, and/or depressive symptoms.

Abstract: Health-related quality of life (HRQOL) of 166 adults who had previously undergone surgical treatment for intractable epilepsy was compared with that of outpatients with hypertension, diabetes, heart disease, and/or depressive symptoms. Eight self-reported HRQOL domains were evaluated and compared by the RAND 36-Item Health Survey 1.0: emotional well-being, social function, role limitations due to emotional problems, energy/fatigue, pain, role limitations due to physical problems, physical function, and general health perceptions. A pictorial item on overall QOL was also administered, for a total of 9 HRQOL domains. With adjustment made for age, gender, education, and comorbid conditions, 55 completely seizure-free patients scored higher (i.e., better health) than patients with hypertension in 6 of 9 domains, higher than diabetic patients in 8 of 9, higher than those with heart disease in all 9, and higher than those with depressive symptoms in all 9 (all p < 0.05). Sixty-seven patients still having seizures with impaired consciousness scored worse than hypertensive patients in 5 domains, worse than diabetic patients in 3, and worse than heart disease patients in 2; for all 3 conditions, these domains included emotional well-being and overall QOL (p < 0.05). These 67 patients, however, scored better than patients with depressive symptoms in all 9 domains, better than those with heart disease in 2, and better than those with diabetes in 1 (all p < 0.05). Forty-four other patients had only simple partial seizures (SPS); their scores were comparable to those of diabetic and heart disease patients on mental and social health scales but were higher ("better") than those of these patients on physical health scales. HRQOL among patients who have undergone "curative" epilepsy surgery is better than that of patients who have hypertension, diabetes, heart disease, or depressive symptoms. Patients who have continued seizures with altered consciousness are worse off in terms of emotional well-being and overall QOL than all other patients, except for those with depressive symptoms.

Measuring the necessity of medical procedures.

Abstract: This is a report on the extension of the concept of the appropriateness of a procedure to the necessity, or crucial importance, of that procedure. To state that a procedure is crucial means that withholding the procedure would be deleterious to the patient's health. Appropriateness and necessity ratings for six procedures were obtained using a modified Delphi panel process developed in earlier work. Panels were composed of practicing clinicians who were recognized leaders in their fields. The panels included both performers and nonperformers of the procedure under discussion. For most procedures and panelists, necessity was related to appropriateness, but was distinct from it. The proportion of indications for which the procedure was crucial varied in clinically consistent ways both among and within procedures. However, panelists did not achieve a consensus on necessity. Further research is suggested to refine the method to promote consensus and to validate further the ratings of necessity. In conclusion, necessity ratings can be used together with appropriateness ratings to address not only the overuse of procedures, but also to indicate limited access to care through underuse of procedures.

Perceptions of punishment : inmates and staff rank the severity of prison versus intermediate sanctions

Abstract: Proponents of the newer intermediate sanctions argue that there are “equivalencies” of punishment between community-based and prison sentences and that, at some level of intensity, community-based programs have roughly the same punitive “bite.” There is little research, however, on the relative severity of intensive supervision in comparison to other sanctions. This study was designed to examine how offenders and staff in Minnesota rank the severity of various criminal sanctions and which particular sanctions they judge equivalent in punitiveness. In addition, we explored how both groups rank the difficulty of commonly imposed probation conditions and which offender background characteristics are associated with perceptions of sanction severity. Our results suggest that there are intermediate sanctions that equate, in terms of punitiveness, with prison. For example, inmates viewed 1 year in prison as “equivalent” in severity to 3 years of intensive probation supervision or 1 year in jail, and they viewed ...

Costing Medical Care: Using Medicare Administrative Data

Abstract: This paper describes how the PORTS are using data from the Medicare administrative records systems to study the medical care costs of specific conditions. The general strengths and weaknesses of the Medicare databases for studying cost related issues are discussed, and the relevant data elements are examined in detail. Changes in the nature of the data collected over time are noted. Information is provided on how the PORTS are using these data to estimate the cost to Medicare of treating Medicare beneficiaries with specific conditions and the social (opportunity) cost of treating these patients. Furthermore, information is provided on how data from the Medicare administrative records system can be used to determine the cost of services for patients who have been identified through other large databases (i.e., state hospital discharge tapes) or who have been enrolled in prospective cohort studies.

Comparison of the appropriateness of coronary angiography and coronary artery bypass graft surgery between Canada and New York State.

Abstract: Objective. —To compare the appropriateness of coronary angiography and coronary artery bypass graft (CABG) use between the United States and Canada. Design. —Retrospective randomized medical record review. Setting. —All hospitals performing coronary angiography and/or CABG surgery in two Canadian provinces (Ontario and British Columbia); in New York State, 15 randomly selected hospitals that provide coronary angiography and 15 randomly selected hospitals that provide CABG surgery. Patients. —All patients were randomly selected. For coronary angiography, 533 patients in Canada and 1333 patients in New York were selected; for CABG, 556 patients in Canada and 1336 patients in New York were selected. Main Outcome Measures. —Percentage of patients in each country who had coronary angiography or CABG for necessary, appropriate, uncertain, or inappropriate indications as rated by criteria developed separately in each country and the complications of those procedures. Results. —For coronary angiography, 9% of Canadian cases and 10% of New York cases were rated inappropriate using Canadian criteria compared with 5% and 4%, respectively, using US criteria. For CABG, 4% of Canadian cases and 6% of New York cases were rated inappropriate by Canadian criteria compared with 3% and 2%, respectively, using US criteria. A lower proportion of procedures were performed on persons aged 75 years or older in Canada than in New York for both coronary angiography (5% vs 11%;P Conclusions. —Rates of inappropriate use of cardiac procedures were low in Canada and New York, which suggests that the regionalization of cardiac procedures that characterizes both health care systems contributes to better clinical decision making. Differences in the use of cardiac procedures among the elderly in the two countries merits further comparative examination. (JAMA. 1994;272:934-940)

First Images of Asteroid 243 Ida

Abstract: The first images of the asteroid 243 Ida from Galileo show an irregular object measuring 56-kilometers by 24 kilometers by 21 kilometers. Its surface is rich in geologic features, including systems of grooves, blocks, chutes, albedo features, crater chains, and a full range of crater morphologies. The largest blocks may be distributed nonuniformly across the surface; lineaments and dark-floored craters also have preferential locations. Ida is interpreted to have a substantial regolith. The high crater density and size-frequency distribution (–3 differential power-law index) indicate a surface in equilibrium with saturated cratering. A minimum model crater age for Ida—and therefore for the Koronis family to which Ida belongs—is estimated at 1 billion years, older than expected.

Empirical Bayes methods for estimating hospital‐specific mortality rates

Abstract: We present alternative methods for estimating hospital-level mortality rates to those used by the Health Care Finance Administration for Medicare patients. We use an empirical Bayes model to represent the different sources of variation in observed hospital-specific mortality rates and we use a logistic regression model to adjust for severity differences (in patient mix) across hospitals. In addition to providing a principled derivation of a standard error for the commonly used estimator, our fully model-based formulation produces much more accurate estimates and resolves the severe problem of multiple comparisons that arises when extreme estimates are used to identify exceptional hospitals. We estimate models for each of four disease conditions using the national Medicare mortality data base which does not contain patient severity descriptors, and mortality data from national samples which do include patient severity descriptors. We find substantial between-hospital variation in the unadjusted death rates from the national data base. Mortality rates differ substantially with patient severity in our models, but the sample sizes are too small to yield reliable estimates of the between-hospital variation in adjusted mortality rates.

Distorting Tendencies in Research on the Homeless

Abstract: The authors argue that the most common research strategy used to study homeless individuals unwittingly presents a distorted picture of the very phenomenon it seeks to illuminate and understand

Management of Heart Failure: IV. Anticoagulation for Patients With Heart Failure Due to Left Ventricular Systolic Dysfunction

Abstract: Objective. —This article reviews the incidence of arterial thromboembolism in patients with heart failure who are not receiving anticoagulants. We also examine whether more severe ventricular dysfunction increases this incidence and the efficacy and risks of anticoagulation for patients in sinus rhythm. Data Sources. —English-language studies referenced in MEDLINE or EMBASE (January 1966 to September 1993) were reviewed. We used the search terms heart failure, congestive; congestive heart failure; heart failure; cardiac failure ; and dilated cardiomyopathy in conjunction with the terms anticoagulation, cerebrovascular disorders, stroke , and thromboembolism . Study Selection. —All studies with separate data for patients with chronic heart failure not receiving anticoagulants were included. Articles addressing valvular heart disease or heart failure secondary to acute myocardial infarction or Chagas' disease were excluded. Studies of the occurrence of left ventricular mural thrombi were also reviewed. Data Extraction and Synthesis. —Inclusion and exclusion criteria, prevalence of atrial fibrillation, mean follow-up, and the occurrence of arterial thromboembolic events were extracted. If the incidence was not given, this was estimated using the proportion of patients with events divided by the mean follow-up. Conclusion. —The incidence of arterial thromboembolism ranged from 0.9 to 5.5 events per 100 patient-years, with the largest studies reporting incidence of 2.0% and 2.4%. Findings regarding the relationship between ventricular function and thromboembolic events are contradictory. No controlled trial has assessed the efficacy or risks of anticoagulation for patients with heart failure and sinus rhythm, and reported efficacy in case series ranged from 0% to 100%. Until adequate studies are performed, anticoagulation should be discouraged for patients with heart failure who are in sinus rhythm. ( JAMA . 1994;272:1614-1618)

Compressed gas energy storage system with cooling capability

Abstract: One aspect of the present invention relates to a process of cogeneration utilizing a compressed gas energy storage system which includes a gas storage area, a compression train for pressurizing a gas to be stored in the gas storage area, and an expansion train for depressurizing high pressure gas released from the gas storage area. The process includes operating the compression train during off-peak electricity utilization periods to produce a compressed gas. The compressed gas is stored in the gas storage area and later released during peak electricity utilization periods through the expansion train to generate electricity. This reduces the compressed gas pressure and temperature. The gas can then be used for refrigeration by contacting it with a material to be chilled with that gas. One aspect of this invention involves generating electricity and effecting refrigeration by depressurization of natural gas from high pipeline transmission pressures to lower distribution pressures. A procedure for energy recovery is also disclosed.

Sociodemographic and health factors in driving patterns after 50 years of age.

Abstract: Data from the 1990 Panel Study of Income Dynamics were used to predict, by means of logistic regression, the likelihood that people who had previously driven would continue to drive and to drive after dark after 50 years of age. The results support the conclusion that driving patterns appear to be explained partly by a combination of sociodemographic factors and health status. Furthermore, it is shown that those reported to drive for nondrivers appear to be the same individuals known to provide most informal support for functionally impaired elderly people.

Gender Differences in Adult Health: An International Comparison

Abstract: This article uses data from the United States, Jamaica, Malaysia, and Bangladesh to explore gender differences in adult health. The results show that women fare worse than men across a variety of self-reported health measures in all four countries studies. These health status disparities between men and women persist even after appropriate corrections are made for the impact of (a) differential mortality selection by gender and (b) sociodemographic factors. Data from Jamaica indicate that gender disparities in adult health arise early and persist throughout the life cycle, with different age profiles for different measures.