David K. Blough

Modeling risk using generalized linear models

Traditionally, linear regression has been the technique of choice for predicting medical risk. This paper presents a new approach to modeling the second part of two-part models utilizing extensions of the generalized linear model. The primary method of estimation for this model is maximum likelihood. This method as well as the generalizations quasi-likelihood and extended quasi-likelihood are discussed. An example using medical expense data from Washington State employees is used to illustrate the methods. The model includes demographic variables as well as an Ambulatory. Care Group variable to account for prior health status.

Treatment With Tissue Plasminogen Activator and Inpatient Mortality Rates for Patients With Ischemic Stroke Treated in Community Hospitals

Background and Purpose— Most analyses of intravenous tissue plasminogen activator (IV tPA) use for acute stroke in routine practice have been limited by sample size and generally restricted to patients treated in large academic medical facilities. In the present study, we sought to estimate among community hospitals the use of IV tPA and to identify factors associated with the use of IV tPA and inpatient mortality. Methods— We evaluated a retrospective cohort of 23 058 patients with ischemic stroke from 137 community hospitals. Results— Three hundred sixty-two (1.6%) patients were treated with IV tPA, and 9.9% of those patients died during the hospitalization period. In 35.0% of the hospitals, no patients were treated with IV tPA, whereas 14.6% of hospitals treated ≈3.0% with IV tPA. After control for multiple factors, younger patients, more severely ill patients (OR 2.02, 95% CI 1.36 to 3.01), and patients treated in rural hospitals (OR 1.80, 95% CI 0.99 to 3.26) were more likely to receive IV tPA, whereas black patients were less likely (OR 0.54, 95% CI 0.31 to 0.95). There also was a trend showing that women were less likely to receive IV tPA (OR 0.84, 95% CI 0.69 to 1.03). Factors associated with an increased odds of inpatient mortality included receipt of IV tPA among men (OR 2.81, 95% CI 1.72 to 4.58) and increased age. Black patients were 27% less likely to die during hospitalization (95% CI 0.60 to 0.90). Conclusions— In this large, retrospective evaluation of community hospital practice, the use IV tPA and inpatient mortality rates among IV tPA–treated patients were consistent with those of other studies. The likelihood of receiving IV tPA varies by race, age, disease severity, and possibly gender. These factors may influence mortality rates.

Washington State Cancer Patients Found To Be At Greater Risk For Bankruptcy Than People Without A Cancer Diagnosis

Much has been written about the relationship between high medical expenses and the likelihood of filing for bankruptcy, but the relationship between receiving a cancer diagnosis and filing for bankruptcy is less well understood. We estimated the incidence and relative risk of bankruptcy for people age twenty-one or older diagnosed with cancer compared to people the same age without cancer by conducting a retrospective cohort analysis that used a variety of medical, personal, legal, and bankruptcy sources covering the Western District of Washington State in US Bankruptcy Court for the period 1995-2009. We found that cancer patients were 2.65 times more likely to go bankrupt than people without cancer. Younger cancer patients had 2-5 times higher rates of bankruptcy than cancer patients age sixty-five or older, which indicates that Medicare and Social Security may mitigate bankruptcy risk for the older group. The findings suggest that employers and governments may have a policy role to play in creating programs and incentives that could help people cover expenses in the first year following a cancer diagnosis.

Are We Optimizing Gestational Diabetes Treatment With Glyburide? The Pharmacologic Basis for Better Clinical Practice

Glyburides pharmacokinetics (PK) and pharmacodynamics have not been studied in women with gestational diabetes mellitus (GDM). The objective of this study was to assess steady‐state PK of glyburide, as well as insulin sensitivity, β‐cell responsivity, and overall disposition indices after a mixed‐meal tolerance test (MMTT) in women with GDM (n = 40), nonpregnant women with type 2 diabetes mellitus (T2DM) (n = 26), and healthy pregnant women (n = 40, MMTT only). At equivalent doses, glyburide plasma concentrations were ~50% lower in pregnant women than in nonpregnant subjects. The average umbilical cord/maternal plasma glyburide concentration ratio at the time of delivery was 0.7 ± 0.4. Insulin sensitivity was approximately fivefold lower in women with GDM as compared with healthy pregnant women. Despite comparable β‐cell responsivity indices, the average β‐cell function corrected for insulin resistance was more than 3.5‐fold lower in women with glyburide‐treated GDM than in healthy pregnant women. Women with GDM in whom glyburide treatment has failed may benefit from alternative medication or dosage escalation; however, fetal safety should be kept in mind.

Using Generalized Linear Models to Assess Medical Care Costs

Medical expenditure data typically exhibit certain characteristics that must be accounted for when deriving cost estimates. First, it is common for a small percentage of patients to incur extremely high costs compared to other patients, resulting in a distribution of expenses that is highly skewed to the right. Second, the assumption of homoscedasticity (constant variance) is often violated because expense data exhibit variability that increases as the mean expense increases. In this paper, we describe the use of the generalized linear model for estimating costs, and discuss several advantages that this technique has over traditional methods of cost analysis. We provide an example, applying this technique to the problem of determining an incidence-based estimate of the cost of care for patients with diabetes who suffer a stroke.

Risk Factors for Financial Hardship in Patients Receiving Adjuvant Chemotherapy for Colon Cancer: A Population-Based Exploratory Analysis

PURPOSE Characteristics that predispose patients to financial hardship during cancer treatment are poorly understood. We therefore conducted a population-based exploratory analysis of potential factors associated with financial hardship and treatment nonadherence during and following adjuvant chemotherapy for colon cancer. PATIENTS AND METHODS Patients diagnosed with stage III colon cancer between 2008 and 2010 were identified from a population-based cancer registry representing 13 counties in Washington state. Patients were asked to complete a comprehensive survey on treatment-related costs. Patients were considered to have experienced financial hardship if they accrued debt, sold or refinanced their home, borrowed money from friends or family, or experienced a 20% or greater decline in their annual income as a result of treatment-related expenses. Logistic regression analysis was used to investigate factors associated with financial hardship and treatment nonadherence. RESULTS A total of 284 responses were obtained from 555 eligible patients (response rate, 51.2%). Nearly all patients in the final sample were insured during treatment. In this sample, 38% of patients reported one or more financial hardships as a result of treatment. The factors most closely associated with treatment-related financial hardship were younger age and lower annual household income. Younger age, lower income, and unemployment or disability (which occurred in most instances following diagnosis) were most closely associated with treatment nonadherence. CONCLUSION A significant proportion of patients undergoing adjuvant chemotherapy for stage III colon cancer may experience financial hardship, despite having health insurance coverage. Interventions to help at-risk patients early on during therapy may prevent long-term financial adverse effects.

The impact of computerized provider order entry on medication errors in a multispecialty group practice

OBJECTIVE Computerized provider order entry (CPOE) has been shown to improve patient safety by reducing medication errors and subsequent adverse drug events (ADEs). Studies demonstrating these benefits have been conducted primarily in the inpatient setting, with fewer in the ambulatory setting. The objective was to evaluate the effect of a basic, ambulatory CPOE system on medication errors and associated ADEs. DESIGN This quasiexperimental, pretest-post-test study was conducted in a community-based, multispecialty health system not affiliated with an academic medical center. The intervention was a basic CPOE system with limited clinical decision support capabilities. MEASUREMENT Comparison of prescriptions written before (n=5016 handwritten) to after (n=5153 electronically prescribed) implementation of the CPOE system. The primary outcome was the occurrence of error(s); secondary outcomes were types and severity of errors. RESULTS Frequency of errors declined from 18.2% to 8.2%-a reduction in adjusted odds of 70% (OR: 0.30; 95% CI 0.23 to 0.40). The largest reductions were seen in adjusted odds of errors of illegibility (97%), use of inappropriate abbreviations (94%) and missing information (85%). There was a 57% reduction in adjusted odds of errors that did not cause harm (potential ADEs) (OR 0.43; 95% CI 0.38 to 0.49). The reduction in the number of errors that caused harm (preventable ADEs) was not statistically significant, perhaps due to few errors in this category. CONCLUSIONS A basic CPOE system in a community setting was associated with a significant reduction in medication errors of most types and severity levels.

Financial Insolvency as a Risk Factor for Early Mortality Among Patients With Cancer

PURPOSE Patients with cancer are more likely to file for bankruptcy than the general population, but the impact of severe financial distress on health outcomes among patients with cancer is not known. METHODS We linked Western Washington SEER Cancer Registry records with federal bankruptcy records for the region. By using propensity score matching to account for differences in several demographic and clinical factors between patients who did and did not file for bankruptcy, we then fit Cox proportional hazards models to examine the relationship between bankruptcy filing and survival. RESULTS Between 1995 and 2009, 231,596 persons were diagnosed with cancer. Patients who filed for bankruptcy (n = 4,728) were more likely to be younger, female, and nonwhite, to have local- or regional- (v distant-) stage disease at diagnosis, and have received treatment. After propensity score matching, 3,841 patients remained in each group (bankruptcy v no bankruptcy). In the matched sample, mean age was 53.0 years, 54% were men, mean income was

The association between 3-hydroxy-3-methylglutaryl conenzyme a inhibitor use and breast carcinoma risk among postmenopausal women: A case-control study

49,000, and majorities were white (86%), married (60%), and urban (91%) and had local- or regional-stage disease at diagnosis (84%). Both groups received similar initial treatments. The adjusted hazard ratio for mortality among patients with cancer who filed for bankruptcy versus those who did not was 1.79 (95% CI, 1.64 to 1.96). Hazard ratios varied by cancer type: colorectal, prostate, and thyroid cancers had the highest hazard ratios. Excluding patients with distant-stage disease from the models did not have an effect on results. CONCLUSION Severe financial distress requiring bankruptcy protection after cancer diagnosis appears to be a risk factor for mortality. Further research is needed to understand the process by which extreme financial distress influences survival after cancer diagnosis and to find strategies that could mitigate this risk.

Adverse Drug Events in Elderly Patients Receiving Home Health Services following Hospital Discharge

Statin use has increased dramatically in the U.S. in the past decade. Animal and mechanistic studies suggested that statins may have an inhibitory effect on cancer proliferation, including breast carcinoma. However, statins have been found to be carcinogenic in rodents and one clinical trial found an excess of breast carcinoma cases in the treatment group.