A guide to interpreting economic studies in infectious diseases.

Healthcare providers continue to seek improved methods for preventing, detecting and treating diseases that affect human survival and quality of life. At the same time, there will always be financial constraints because of limited societal resources. Many of the discussions on how to provide economically sound solutions to this challenge have not fully engaged the input of clinicians in the field. The purpose of this review is to increase economic knowledge for clinicians. We cover healthcare cost elements and methods used to assign value to a health outcome. We outline the challenges in conducting economic studies in the field of infectious diseases. Finally, we discuss the meaning of efficiency from multiple perspectives, and how the concept of economic externalities applies to infectious diseases.

Association of educational attainment with HIV risk in African American active injection drug users.

This study explored the association between educational attainment and HIV/AIDS risk among African American active injection drug users (IDUs) in Chicago, US. Using snowball sampling techniques, 813 African American active IDUs were recruited for semi-structured interviewing and HIV counseling, testing and partner notification. Logistic regression examined the relationship between level of education attained (three categories: less than high school; equivalent to high school; and greater than high school) and HIV risk behaviors (12 unsafe sex and drug-related practices) and HIV serostatus (positive or negative). Compared with the reference category (less than high school education), those with education equal to high school were less likely to share water, p = 0.044, OR = 0.70 (95%CI: 0.50-0.99). Compared with the reference category, those with education greater than high school were less likely to receive money for sex, p = 0.048, OR = 0.62 (95%CI: 0.38-0.99); share needles with person having HIV or AIDS, p = 0.015, OR = 0.58 (95%CI: 0.37-0.90); and test positive for HIV, p = 0.027, OR = 0.58 (95%CI: 0.36-0.94). The significant associations found between educational attainment and certain HIV risk behaviors and HIV serostatus have implications for tailoring HIV prevention efforts for less educated African American IDUs.

Influence of religiosity on HIV risk behaviors in active injection drug users.

Previous studies have shown a positive relationship between religiosity and the practice or adoption of protective health behaviors, including reduction of illicit drug use among hard-core injecting drug users (IDUs). The purpose of this study was to examine the role of religiosity in predicting HIV high-risk drug and sexual practices among a sample of IDUs in Chicago, USA. We hypothesized that high religiosity would be associated with a lower likelihood of IDUs engaging in risky behaviors for HIV transmission. Snowball sampling techniques were used to recruit 1,095 active IDUs for HIV testing, counseling and partner notification. Data were analyzed from 880 subjects who self-identified with one of three religions, Christianity, Islam or Judaism. Logistic regression was used to examine the relationship between religiosity (based on self-reports of personal strength of religious belief: very strong; somewhat strong; not at all), independent of specific religion, and HIV risk behaviors (defined as 12 unsafe sex- and drug-related practices) as well as HIV serostatus. Contrary to our hypothesis, subjects with stronger religiosity were more likely to engage in four risk behaviors related to sharing injection paraphernalia. Compared to those who self-reported having no religiosity, subjects who stated that their lives were strongly influenced by religious beliefs were significantly more likely to share injection outfits, cookers, cotton and water. The association of certain HIV risk behaviors with higher religiosity has implications for HIV prevention and warrants further research to explore IDUs' interpretation of religious teachings and the role of religious education in HIV prevention programs.

Distribution of variable vs fixed costs of hospital care.

CONTEXT: Most strategies proposed to control the rising cost of health care are aimed at reducing medical resource consumption rates. These approaches may be limited in effectiveness because of the relatively low variable cost of medical care. Variable costs (for medication and supplies) are saved if a facility does not provide a service while fixed costs (for salaried labor, buildings, and equipment) are not saved over the short term when a health care facility reduces service. OBJECTIVE: To determine the relative variable and fixed costs of inpatient and outpatient care for a large urban public teaching hospital. DESIGN: Cost analysis. SETTING: A large urban public teaching hospital. MAIN OUTCOME MEASURES: All expenditures for the institution during 1993 and for each service were categorized as either variable or fixed. Fixed costs included capital expenditures, employee salaries and benefits, building maintenance, and utilities. Variable costs included health care worker supplies, patient care supplies, diagnostic and therapeutic supplies, and medications. RESULTS: In 1993, the hospital had nearly 114000 emergency department visits, 40000 hospital admissions, 240000 inpatient days, and more than 500000 outpatient clinic visits. The total budget for 1993 was $429.2 million, of which $360.3 million (84%) was fixed and $68.8 million (16%) was variable. Overall, 31.5% of total costs were for support expenses such as utilities, employee benefits, and housekeeping salaries, and 52.4% included direct costs of salary for service center personnel who provide services to individual patients. CONCLUSIONS: The majority of cost in providing hospital service is related to buildings, equipment, salaried labor, and overhead, which are fixed over the short term. The high fixed costs emphasize the importance of adjusting fixed costs to patient consumption to maintain efficiency.

Costs of an emergency department-based accelerated diagnostic protocol vs hospitalization in patients with chest pain: a randomized controlled trial.

CONTEXT: More than 3 million patients are hospitalized yearly in the United States for chest pain. The cost is over $3 billion just for those found to be free of acute disease. New rapid diagnostic tests for acute myocardial infarction (AMI) have resulted in the proliferation of accelerated diagnostic protocols (ADPs) and chest pain observation units. OBJECTIVE: To determine whether use of an emergency department (ED)-based ADP can reduce hospital admission rate, total cost, and length of stay (LOS) for patients needing admission for evaluation of chest pain. DESIGN: Prospective randomized controlled trial comparing admission rate, total cost, and LOS for patients treated using ADP vs inpatient controls. Total costs were determined using empirically measured resource utilization and microcosting techniques. SETTING: A large urban public teaching hospital serving a predominantly African American and Hispanic population. PATIENTS: A sample of 165 patients was randomly selected from a larger consecutive sample of 429 patients with chest pain concurrently enrolled in an ADP diagnostic cohort trial. Eligible patients presented to the ED with clinical findings suggestive of AMI or acute cardiac ischemia (ACI) but at low risk using a validated predictive algorithm. MAIN OUTCOME MEASURES: Primary outcomes measured for each subject were LOS and total cost of treatment. RESULTS: The hospital admission rate for ADP vs control patients was 45.2% vs 100% (P<.001). The mean total cost per patient for ADP vs control patients was $1528 vs $2095 (P<.001). The mean LOS measured in hours for ADP vs control patients was 33.1 hours vs 44.8 hours (P<.01). CONCLUSIONS: In this trial, ADP saved $567 in total hospital costs per patient treated. Use of ED-based ADPs can reduce hospitalization rates, LOS, and total cost for low-risk patients with chest pain needing evaluation for possible AMI or ACI.

Feasibility of a rapid diagnostic protocol for an emergency department chest pain unit.

STUDY OBJECTIVE: To evaluate the applicability of a short-stay protocol for exclusion of acute ischemic heart disease without hospital admission and to analyze these results in the context of a conceptual model. METHODS: An observational study of patients who presented with chest pain to the emergency department of an 886-bed inner-city municipal hospital and who needed hospital admission to rule out acute myocardial infarction (AMI). Patients were assessed by ED attending physicians to determine eligibility for an alternative, 12-hour protocol in an ED chest pain observation unit (CPOU) followed by immediate exercise testing. Outcome measures were proportion of patients eligible for the short-stay protocol, risk factor profile, and reasons for exclusion. RESULTS: Of 500 patients screened, 446 had sufficient data points to determine protocol eligibility. Of these, 238 (53.3%; 95% confidence interval [CI], 48.7% to 57.9%) were found to have low probability for AMI. After study exclusion criteria were applied to the patient cohort, 63 patients (14.1%; 95% CI, 10.9% to 17.3%) were eligible for the protocol. The most common reasons for exclusion were history of coronary artery disease (46%) and inability to perform an interpretable exercise tolerance test (42%). CONCLUSION: Although most admitted patients with chest pain (53%) were at low probability for AMI, only a minority (14%) were eligible for a short-stay protocol that required patients to be free of known coronary artery disease and able to perform an exercise tolerance test. Factors affecting the operations and efficiency of a CPOU include clinical characteristics of the target patient population, protocol tests used, and hospital occupancy and reimbursement patterns.

An Indicator of Solid Waste Generation Potential for Illinois Using Principal Components Analysis and Geographic Information Systems.

An indicator of solid waste generation potential (SWGP) is proposed as a versatile means to assist the development of integrated solid waste (SW) management plans. The proposed indicator is based on key sodoeconomic variables for the State of Illinois which were found to be highly correlated with variables describing the SW stream of the State. The proposed indicator was derived by applying the principal components analysis (PCA) technique. The technique is used to merge the rank transformed socioeconomic variables into a single variable, the SWGP indicator, while maintaining the regional information of the original variables. An innovative aspect of this indicator approach is the use of the ordinal scale for all these diverse variables. The validity of this approach was assessed and the proposed indicator was found to be directly proportional to a composite variable describing the SW stream for the State of Illinois. The use of Geographic Information Systems (GIS) to depict the spatial distribution of the SWGP will help planners visualize the expected overall refuse generation pattern and to identify critical regions. In addition, the proposed indicator could be used as an instrument to validate the solid waste generation (SWG) quantities reported by counties to state agencies.