Biomedical subjects

Dana Goldman

Publications and source records attributed to Dana Goldman.

4 recordsLinked to original sources

PubMed2006

Estimating probit models with self-selected treatments.

Outcomes research often requires estimating the impact of a binary treatment on a binary outcome in a non-randomized setting, such as the effect of taking a drug on mortality. The data often come from self-selected samples, leading to a spurious correlation between the treatment and outcome when standard binary dependent variable techniques, like logit or probit, are used. Intuition suggests that a two-step procedure (analogous to two-stage least squares) might be sufficient to deal with this problem if variables are available that are correlated with the treatment choice but not the outcome. This paper demonstrates the limitations of such a two-step procedure. We show that such estimators will not generally be consistent. We conduct a Monte Carlo exercise to compare the performance of the two-step probit estimator, the two-stage least squares linear probability model estimator, and the multivariate probit. The results from this exercise argue in favour of using the multivariate probit rather than the two-step or linear probability model estimators, especially when there is more than one treatment, when the average probability of the dependent variable is close to 0 or 1, or when the data generating process is not normal. We demonstrate how these different methods perform in an empirical example examining the effect of private and public insurance coverage on the mortality of HIV+ patients.

Anti-HIV Agents↗

PubMed2004

Effect of an imaging-based streamlined electronic healthcare process on quality and costs.

RATIONALE AND OBJECTIVES: A streamlined process of care supported by technology and imaging may be effective in managing the overall healthcare process and costs. This study examined the effect of an imaging-based electronic process of care on costs and rates of hospitalization, emergency room (ER) visits, specialist diagnostic referrals, and patient satisfaction. MATERIALS AND METHODS: A healthcare process was implemented for an employer group, highlighting improved patient access to primary care plus routine use of imaging and teleconsultation with diagnostic specialists. An electronic infrastructure supported patient access to physicians and communication among healthcare providers. The employer group, a self-insured company, manages a healthcare plan for its employees and their dependents: 4,072 employees were enrolled in the test group, and 7,639 in the control group. Outcome measures for expenses and frequency of hospitalizations, ER visits, traditional specialist referrals, primary care visits, and imaging utilization rates were measured using claims data over 1 year. Homogeneity tests of proportions were performed with a chi-square statistic, mean differences were tested by two-sample t-tests. Patient satisfaction with access to healthcare was gauged using results from an independent firm. RESULTS: Overall per member/per month costs post-implementation were lower in the enrolled population (126 dollars vs 160 dollars), even though occurrence of chronic/expensive diseases was higher in the enrolled group (18.8% vs 12.2%). Lower per member/per month costs were seen for inpatient (33.29 dollars vs 35.59 dollars); specialist referrals (21.36 dollars vs 26.84 dollars); and ER visits (3.68 dollars vs 5.22 dollars). Moreover, the utilization rate for hospital admissions, ER visits, and traditional specialist referrals were significantly lower in the enrolled group, although primary care and imaging utilization were higher. Comparison to similar employer groups showed that the company's costs were lower than national averages (119.24 dollars vs 146.32 dollars), indicating that the observed result was not attributable to normalization effects. Patient satisfaction with access to healthcare ranked in the top 21st percentile. CONCLUSION: A streamlined healthcare process supported by technology resulted in higher patient satisfaction and cost savings despite improved access to primary care and higher utilization of imaging.

Electronics, Medical↗

PubMed2004

Increased Medicare expenditures for physicians' services: what are the causes?

In light of rising expenditures for physicians' services and the scheduled decreases in the amounts Medicare pays for such services, we identified the sources of change in the volume and intensity of Medicare physicians' services. We found that the per capita volume and intensity of physicians services used by Medicare beneficiaries increased more than 30% between 1993 and 1998. Our analyses indicated that, at most, half of this increase was due to measurable changes in the demographic composition, places of residence, prevalence of health conditions, and managed care enrollment of beneficiaries. The other half was due to a general increase in the use of care across beneficiary categories.

Aged↗

PubMed2003

The link between public and private insurance and HIV-related mortality.

As policymakers consider expanding insurance coverage for the human immunodeficiency virus (HIV+) population, it is useful to ask whether insurance has any effect on health outcomes, and, if so, whether public insurance is as efficacious as private insurance in preventing premature death. Using data from a nationally representative cohort of HIV-infected persons receiving regular medical care, we estimate the impact of different types of insurance on mortality in this population. Our main findings are that (1) ignoring observed and unobserved health status misleads one to conclude that insurance may not be protective for HIV patients, (2) after accounting for observed and unobserved heterogeneity, insurance does protect against premature death, and (3) private insurance is more effective than public insurance. The better performance of private insurance can be explained in part by more restrictive Medicaid prescription drug policies that limit access to highly efficacious treatment.

Adolescent↗