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Biomedical subjects

David A Ganz

Publications and source records attributed to David A Ganz.

11 recordsLinked to original sources

Will my patient fall?

CONTEXT: Effective multifactorial interventions reduce the frequent falling rate of older patients by 30% to 40%. However, clinical consensus suggests reserving these interventions for high-risk patients. Limiting fall prevention programs to high-risk patients implies that clinicians must recognize features that predict future falls. OBJECTIVE: To identify the prognostic value of risk factors for future falls among older patients. DATA SOURCES AND STUDY SELECTION: Search of MEDLINE (1966-September 2004), CINAHL (1982-September 2004), and authors' own files to identify prospective cohort studies of risk factors for falls that performed a multivariate analysis of such factors. DATA EXTRACTION: Two reviewers independently determined inclusion of articles and assessed study quality. Disagreements were resolved by consensus. Included studies were those identifying the prognostic value of risk factors for future falls among community-dwelling persons 65 years and older. Clinically identifiable risk factors were identified across 6 domains: orthostatic hypotension, visual impairment, impairment of gait or balance, medication use, limitations in basic or instrumental activities of daily living, and cognitive impairment. DATA SYNTHESIS: Eighteen studies met inclusion criteria and provided a multivariate analysis including at least 1 of the risk factor domains. The estimated pretest probability of falling at least once in any given year for individuals 65 years and older was 27% (95% confidence interval, 19%-36%). Patients who have fallen in the past year are more likely to fall again [likelihood ratio range, 2.3-2.8]. The most consistent predictors of future falls are clinically detected abnormalities of gait or balance (likelihood ratio range, 1.7-2.4). Visual impairment, medication variables, decreased activities of daily living, and impaired cognition did not consistently predict falls across studies. Orthostatic hypotension did not predict falls after controlling for other factors. CONCLUSIONS: Screening for risk of falling during the clinical examination begins with determining if the patient has fallen in the past year. For patients who have not previously fallen, screening consists of an assessment of gait and balance. Patients who have fallen or who have a gait or balance problem are at higher risk of future falls.

Accidental Falls↗

Quality of osteoarthritis care for community-dwelling older adults.

OBJECTIVE: To describe the quality of osteoarthritis care provided to community-dwelling elderly patients and to characterize arthritis-related function in these patients. METHODS: Two medical groups in the western United States participated in a practice-redesign intervention targeted at falls and mobility disorders, incontinence, and cognitive impairment, but not osteoarthritis. From 339 individuals reporting a diagnosis of arthritis, we collected information on demographics, functional status, and quality of care via patient interviews and mailed questionnaires. Eight quality indicators measured osteoarthritis care: 4 indicators measuring the provision of effective osteoarthritis care (osteoarthritis treatment indicators) and 4 measuring the provision of safe osteoarthritis care (medication safety indicators). RESULTS: The mean +/- SD Short Form 12 physical component summary score was 35 +/- 11 points, indicating a physically frail population. The overall indicator pass rate was 57.0% (95% confidence interval [95% CI] 53.9-60.2). Pass rates were higher for indicators of osteoarthritis treatment (63.5%, 95% CI 59.8-67.2) than for indicators of medication safety (43.8%, 95% CI 38.2-49.4). Patients with hip or knee pain had mean +/- SD Western Ontario and McMaster Universities Osteoarthritis Index pain, stiffness, and function scores of 6.0 +/- 4.0, 3.1 +/- 1.7, and 25 +/- 12 points, respectively. CONCLUSION: Quality of osteoarthritis care for older adults is suboptimal, particularly with regard to medication safety. Given the high prevalence of osteoarthritis in older age groups, the population impact of any improvement in quality would be substantial. Quality improvement efforts for osteoarthritis should target appropriate use of and counseling regarding medications, as well as underuse of efficacious therapy for osteoarthritis.

Aged, 80 and over↗

Cost-effectiveness of recommended nurse staffing levels for short-stay skilled nursing facility patients.

BACKGROUND: Among patients in skilled nursing facilities for post-acute care, increased registered nurse, total licensed staff, and nurse assistant staffing is associated with a decreased rate of hospital transfer for selected diagnoses. However, the cost-effectiveness of increasing staffing to recommended levels is unknown. METHODS: Using a Markov cohort simulation, we estimated the incremental cost-effectiveness of recommended staffing versus median staffing in patients admitted to skilled nursing facilities for post-acute care. The outcomes of interest were life expectancy, quality-adjusted life expectancy, and incremental cost-effectiveness. RESULTS: The incremental cost-effectiveness of recommended staffing versus median staffing was $321,000 per discounted quality-adjusted life year gained. One-way sensitivity analyses demonstrated that the cost-effectiveness ratio was most sensitive to the likelihood of acute hospitalization from the nursing home. The cost-effectiveness ratio was also sensitive to the rapidity with which patients in the recommended staffing scenario recovered health-related quality of life as compared to the median staffing scenario. The cost-effectiveness ratio was not sensitive to other parameters. CONCLUSION: Adopting recommended nurse staffing for short-stay nursing home patients cannot be justified on the basis of decreased hospital transfer rates alone, except in facilities with high baseline hospital transfer rates. Increasing nurse staffing would be justified if health-related quality of life of nursing home patients improved substantially from greater nurse and nurse assistant presence.

Computer Simulation↗

Pharmacogenetic testing in the clinical management of schizophrenia: a decision-analytic model.

Clinical application of pharmacogenetic testing has been proposed as a means of improving treatment outcomes in psychiatry. The identification of a putative genetic test for better clozapine response in schizophrenia offers an opportunity to evaluate the cost-effectiveness of such testing. The authors performed a cost-effectiveness analysis of a genetic test that may identify individuals with greater likelihood of responding to clozapine treatment. We modeled a target population of schizophrenia patients in an acute psychotic episode, using a lifetime time horizon and societal perspective. Outcome measures included life expectancy, quality-adjusted life expectancy, costs, and incremental cost-effectiveness. Effects of variations in testing parameters were also examined. For a 30-year-old with schizophrenia, applying the pharmacogenetic test and treating those predicted to respond to clozapine with clozapine-first cost US $47,705 per additional quality-adjusted life-year, compared with treating all patients with conventional agents and reserving clozapine for treatment-resistant patients. In 1-way sensitivity analyses, test sensitivity and cost had the greatest impact on the incremental cost-effectiveness. We conclude that pharmacogenetic tests may achieve utility in clinical psychiatry, although their cost-effectiveness depends on several clinical parameters. More consistent reporting of test parameters such as sensitivity and specificity would greatly facilitate assessment of future pharmacogenetic studies.

Antipsychotic Agents↗

Monitoring falls in cohort studies of community-dwelling older people: effect of the recall interval.

OBJECTIVES: To determine whether the interval over which patients are asked to remember their falls affects fall reporting. DESIGN: Systematic literature review. SETTING: Community. PARTICIPANTS: Individuals being monitored for falls in prospective studies that asked participants to recall falls over varying intervals. MEASUREMENTS: Sensitivity and specificity of retrospective recall compared with a criterion-standard prospective assessment using some form of ongoing fall monitoring. RESULTS: Six studies met the inclusion criteria. Recall of falls in the previous year was specific (specificity 91-95%) but less sensitive (sensitivity 80-89%) than the criterion standard of ongoing prospective collection of fall data using fall calendars or postcards. Patients with injurious falls were more likely to recall their falls. Lower Mini-Mental State Examination score was associated with poorer recall of falls in the one study addressing this issue. CONCLUSION: Whenever accurate data on all falls are critical, such as with interventions to decrease the rate of falls, researchers should gather information on falls every week or every month from study participants. The optimal method of fall monitoring--postcard, calendar, diary, telephone, or some combination of these--remains unknown.

Accidental Falls↗

Therapeutic delay and reduced functional status six months after thrombolysis for acute myocardial infarction.

Thrombolytic therapy decreases the mortality rate in patients with acute myocardial infarction (AMI), and the timing of thrombolysis has proved to be critical for decreasing the short-term mortality rate. Much less is known about the longer term consequences of delays in thrombolysis, particularly for outcomes other than the mortality rate. We assessed the effect of time to thrombolysis and other clinical predictors on cardiac functional status 6 months after AMI. We used InTIME II, a multicenter trial, to test the efficacy of alteplase and lanoteplase. This component of the trial was conducted in 147 North American centers. Patients were > or =18 years of age with ST-elevated AMI. Functional status was measured by the Duke Activity Status Index, which was administered 6 months after AMI. After multivariate adjustment for baseline characteristics, delay in presentation to hospital and delay in initiation of thrombolysis were significantly and independently associated with decreased cardiac functional status 6 months later. Each additional hour from symptom onset to hospital presentation was associated with a 16% increase (95% confidence interval 3% to 31%) in the likelihood of functional impairment (Duke Activity Status Index score < or =30). In addition, each additional delay of 1 hour from hospital presentation to thrombolysis independently increased the probability of functional impairment by 38% (12% to 71%). Thus, in patients with AMI, earlier presentation to the hospital and more rapid initiation of thrombolysis could prevent significant decreases in functional status months after the initial infarct.

Activities of Daily Living↗

Should clozapine continue to be restricted to third-line status for schizophrenia?: a decision-analytic model.

BACKGROUND: Clozapine is currently restricted to patients who have failed at least two trials of other antipsychotic medications because of concerns that its use as a first-line agent would lead to greater mortality, mainly through agranulocytosis. AIMS OF THE STUDY: We sought to determine the cost-effectiveness of allowing clozapine to be a first-line treatment versus the current policy of restricting clozapine to third-line status. METHODS: We performed a cost-effectiveness analysis using published data from randomized controlled trials and epidemiologic studies. The target population was patients with schizophrenia in an acute psychotic episode, with a lifetime time horizon and societal perspective. Outcome measures included life expectancy, quality-adjusted life expectancy, costs, and cost-effectiveness ratios. RESULTS: Using clozapine as a first agent would lead to modest gains in life-expectancy as well as quality-adjusted life expectancy, relative to restricting its use to patients who failed 2 conventional antipsychotics. The cost-effectiveness ratio of using clozapine first vs. using clozapine third would be $24,100 per quality-adjusted life year (QALY). In 1-way and probabilistic sensitivity analyses, these findings were robust to a variety of assumptions. DISCUSSION: Allowing clozapine to be a first-line agent may lead to small gains in life expectancy at moderate but acceptable costs. IMPLICATIONS: While these results do not shed light on whether clozapine should be the preferred first-line strategy, they do suggest that clozapine should be added to the armamentarium of possible treatments for treatment-sensitive as well as treatment-resistant schizophrenia.

Adult↗

Measuring the cost-effectiveness of lipid-lowering drugs in the elderly: the outcomes research and economic analysis components of the PROSPER trial.

Little information exists to quantify the functional status and economic consequences of lipid-lowering therapy in elderly patients. We describe the design of the cost-effectiveness component of the first large, randomized, placebo-controlled trial of lipid-lowering therapy in subjects aged 70 years or older. The PROspective Study of Pravastatin in the Elderly at Risk has randomized 5804 men and women 70-82 years old, with existing vascular disease or related risk factors, to receive 40 mg/d of pravastatin or placebo. The cost-effectiveness study will be based on within-trial observations of differences between the two study arms in rates of myocardial infarction, stroke and related vascular disease outcomes (including vascular dementia). In addition to comparing within-trial clinical outcomes, we will model the projected changes in life expectancy and cardiovascular outcome rates that would be seen with lifelong use of the drug, based on the risk reduction rates seen in the trial as well as baseline observational data from the three countries where the trial is being conducted (Scotland, Ireland and the Netherlands). A state transition (Markov) model will be constructed to estimate the likely states of health, functional status and health care resource utilization (including lipid-lowering drug costs) in a cohort of elderly patients with versus without pravastatin therapy over a series of 1-year cycles until death. In addition, a standard measure of utility (the Health Utilities Index) will be administered to all study subjects to permit calculation of quality-adjusted life-years gained with this regimen. This approach will make it possible to go beyond the calculation of a single endpoint for each subject, and to translate the trial findings into definitions of effectiveness and outcomes that will be relevant to the ongoing debate concerning how best to relate the benefits of such medications to their costs.

Aged↗

Which patients with unstable angina or non-Q-wave myocardial infarction should have immediate cardiac catheterization? A clinical decision rule for predicting who will fail medical therapy.

Unstable angina and non-Q-wave myocardial infarction (MI) are common and costly clinical events, but there is considerable uncertainty about optimal clinical management of these syndromes. We developed a prediction rule to help clinicians determine which patients with unstable angina or non-Q-wave MI are likely to "fail" medical therapy and ultimately require cardiac catheterization within 6 weeks of presentation. Subjects were 733 patients presenting with unstable angina or non-Q-wave MI enrolled in the TIMI IIIB trial and randomized to initial medical management. We developed a prediction rule based on logistic regression analysis of baseline data from history, physical examination, electrocardiogram, and blood studies. The outcome of interest was "failure" of medical therapy, defined as need for coronary catheterization within 42 days. Significant predictors of "failing" medical therapy included ST segment depression >or= .1 mV (odds ratio, OR, = 2.7, 95% confidence interval, CI, 1.8-4.1), accelerated angina in the prior 2 months (OR = 1.8, 95% CI 1.2-2.6), nitrate use in the prior week (OR = 1.6, 95% CI 1.1-2.2), exertional angina in the prior 2 months (OR = 1.6, 95% CI 1.1-2.2), and cardiac troponin I (cTnI) >or= 0.4 ng/mL (OR = 1.4, 95% CI 1.1-1.9). We used these variables to build a risk score by assigning point values based on these ORs. The risk score had a moderate ability to predict which patients would subsequently fail medical therapy and undergo cardiac catheterization (c = 0.682). Out of a total risk score of 13, failure of medical therapy occurred in 86% of patients who had a risk score >or= 8 (n = 111), 78% of patients who had a risk score >or= 6 (n = 240), and 72% of patients who had a risk score >or= 4 (n = 438). At scores of < 2 (n = 88), 40% of patients failed medical therapy. Although the management of unstable angina is in constant evolution, clinicians will always be faced with determining which patients should be managed most invasively. The simple prediction rule we present can be applied to patients with unstable angina or non-Q-wave MI at the time of presentation to predict which patients have a high probability of failing medical therapy. Such a rule may be useful for identifying patients who should be considered for early cardiac catheterization.

Adult↗

Clozapine use and risk of diabetes mellitus.

Recent reports have raised the concern that clozapine increases the risk for diabetes mellitus. Accurate pharmacoepidemiologic data on whether such a hazard exists and its magnitude are needed to enable clinicians and patients to make proper treatment decisions about clozapine. The authors performed a case-control study involving 7,227 cases of newly treated diabetes and 6,780 controls, all with psychiatric disorders. Cases and controls were older than 20 years and enrolled in government-sponsored drug benefit programs in New Jersey. The authors measured the use of clozapine or other antipsychotic medications and additional covariates. They developed logistic regression models adjusted for demographic, clinical, and health care use characteristics to identify whether clozapine users were at increased risk to begin treatment for diabetes. Clozapine use was not significantly associated with developing diabetes (adjusted odds ratio [OR], 0.98; 95% confidence interval [CI], 0.74-1.31). There was no suggestion of relationships between larger dosages or longer durations of clozapine use and increasing risks of diabetes. On the other hand, nonclozapine antipsychotic medication use was associated with a modest but significantly increased risk of developing diabetes (adjusted OR, 1.13; 95% CI, 1.05-1.22). Among individual nonclozapine antipsychotics, significantly elevated risks were observed for two phenothiazine agents: chlorpromazine (adjusted OR, 1.31; 95% CI, 1.09-1.56) and perphenazine (adjusted OR, 1.34; 95% CI, 1.11- 1.62). In contrast to earlier reports, these results provide some reassurance that clozapine does not increase the risk of developing diabetes. Additional data from pharmacoepidemiologic studies and randomized controlled trials are needed to exclude the possibility of residual confounding and ensure the appropriate use of this agent.

Adult↗