Biomedical subjects

John L Adams

Publications and source records attributed to John L Adams.

23 records · Page 2Linked to original sources

PubMed2003

Methodological challenges associated with patient responses to follow-up longitudinal surveys regarding quality of care.

OBJECTIVE: To illustrate, using empirical data, methodological challenges associated with patient responses to longitudinal surveys regarding the quality of process of care and health status, including overall response rate, differential response rate, and stability of responses with time. DATA SOURCES/STUDY SETTING: Primary patient self-report data were collected from 30,308 patients in 1996 and 13,438 patients in 1998 as part of a two-year longitudinal study of quality of care and health status of patients receiving care delivered by 63 physician organizations (physician groups) across three West Coast states. STUDY DESIGN: We analyzed longitudinal, observational data collected by Pacific Business Group on Health (PBGH) from patients aged 18-70 using a four-page survey in 1996 and a similar survey in 1998 to assess health status, satisfaction, use of services, and self-reported process of care. A subset of patients with self-reported chronic disease in the 1996 study received an enriched survey in 1998 to more fully detail processes of care for patients with chronic disease. DATA COLLECTION/EXTRACTION METHODS: We measured response rate overall and separately for patients with chronic disease. Logistic regression was used to assess the impact of 1996 predictors on response to the follow-up 1998 survey. We compared process of care scores without and with nonresponse weights. Additionally, we measured stability of patient responses over time using percent agreement and kappa statistics, and examined rates of gender inconsistencies reported across the 1996 and 1998 surveys. PRINCIPAL FINDINGS: In 1998, response rates were 54 percent overall and 63 percent for patients with chronic disease. Patient demographics, health status, use of services, and satisfaction with care in 1996 were all significant predictors of response in 1998, highlighting the importance of analytic strategies (i.e., application of nonresponse weights) to minimize bias in estimates of care and outcomes associated with longitudinal quality of care and health outcome analyses. Process of care scores weighted for nonresponse differed from unweighted scores (p<.001). Stability of responses across time was moderate, but varied by survey item from fair to excellent. CONCLUSIONS: Longitudinal analyses involving the collection of data from the same patients at two points in time provide opportunities for analysis of relationships between process and outcomes of care that cannot occur with cross-sectional data. We present empirical results documenting the scope of the problems and discuss options for responding to these challenges. With increasing emphasis in the United States on quality reporting and use of financial incentives for quality in the health care market, it is important to identify and address methodological challenges that potentially threaten the validity of quality-of-care assessments.

Adult↗

PubMed2003

Sampling patients within physician practices and health plans: multistage cluster samples in health services research.

OBJECTIVE: To better inform study design decisions when sampling patients within health plans and physician practices with multiple analysis goals. STUDY SETTING: Chronic eye care patients within six health plans across the United States. STUDY DESIGN: We developed a simulation-based approach for designing multistage samples. We created a range of candidate designs, evaluated them with respect to multiple sampling goals, investigated their tradeoffs, and identified the design that is the best compromise among all goals. This approach recognizes that most data collection efforts have multiple competing goals. DATA COLLECTION: We constructed a sample frame from all diabetic patients in six health plans with evidence of chronic eye disease (glaucoma and retinopathy). PRINCIPAL FINDINGS: Simulations of different study designs can uncover efficiency gains as well as inform potential tradeoffs among study goals. Simulations enable us to quantify these efficiency gains and to draw tradeoff curves. CONCLUSIONS: When designing a complex multistage sample it is desirable to explore the tradeoffs between competing sampling goals via simulation. Simulations enable us to investigate a larger number of candidate designs and are therefore likely to identify more efficient designs.

Cluster Analysis↗

PubMed2002

Increased risk of serious injury following an initial prescription for diphenhydramine.

BACKGROUND: Diphenhydramine may be associated with excess risk of injury relative to nonsedating H1-receptor antagonists. OBJECTIVE: This study sought to compare the risk of injury in patients exposed to diphenhydramine with the risk of injury in patients exposed to loratadine. METHODS: A retrospective cohort study of injury was carried out in 12,106 patients whose initial antihistamine prescription was for diphenhydramine and in 24,968 patients whose initial antihistamine prescription was for loratadine. Data were taken from a health care claims database that included employees, dependents, and retirees who filed claims from January 1991 through December 1998. Rates of six serious injuries in the diphenhydramine cohort after and before the first prescription were compared with rates in the loratadine cohort after and before the first prescription. RESULTS: In the 30 days after the first antihistamine prescription, the rate of all injuries was 308 per 1,000 person-years in the diphenhydramine cohort versus 137 per 1,000 person-years in the loratadine cohort. The rate ratio estimate adjusted for age and gender using Poisson regression was 2.27 (95% confidence limits [CL] 1.93, 2.66). In the corresponding 30 days of the preceding year, the injury rates in the diphenhydramine and loratadine cohorts were 128 and 125 per 1,000 person-years, and the adjusted rate ratio was 1.02 (CL 0.83, 1.26). Thus, the cohorts appeared to have similar preprescription injury rates. The differences between the cohorts declined with time from prescription: For all injuries, the estimated percentage decline in the rate ratio was 4.1% per day (CL 3.3, 4.9), and the estimated time from the initial prescription until the diphenhydramine cohort returned to baseline risk was 32.3 days (CL 26.9, 37.6). CONCLUSIONS: If these associations are causal, the percentage of the injuries attributable to diphenhydramine was 55% (CL 41, 65), implying a substantial number of excess injuries and costs incurred as the result of diphenhydramine use. The high use rates of this drug and the high incidence of injury suggest that further study of the association between injury and type of antihistamine is needed.

Adolescent↗

PubMed2002

Antimicrobial prophylaxis for urinary tract infection in persons with spinal cord dysfunction.

OBJECTIVE: To assess the benefits and harms of antimicrobial prophylaxis to prevent urinary tract infections (UTIs) in persons with neurogenic bladders caused by spinal cord dysfunction. DATA SOURCES: A broad search strategy with no language restriction was conducted of MEDLINE (1966-January 1998), EMBASE (1974-January 1998), and CINAHL (1982-July 1998) using the general search terms urinary tract, urinary tract infections, bacteriuria, paraplegia, quadriplegia, spinal cord injuries, multiple sclerosis, neurogenic bladder, and neuropathic bladder. Additional articles were identified by experts and by reviewing reference lists of articles obtained from searches. STUDY SELECTION: Criteria included human studies of adults and adolescents who had neurogenic bladder due to spinal cord dysfunction; the studies had to address antimicrobial prophylaxis of UTI and include bacteriuria or UTI as an outcome. We excluded any study that was clearly not a controlled trial or that only included children under the age of 13 years. Two reviewers independently abstracted data, and disagreements were resolved by consensus. DATA EXTRACTION: Two reviewers independently abstracted data, and disagreements were resolved by consensus. Studies were graded by 1 project investigator according to quality criteria developed by Jadad and Schulz. DATA SYNTHESIS: The sizes of the effect of antimicrobial prophylaxis on weekly infection rates from 15 trials that met the inclusion criteria were pooled by using a random effects model. Antimicrobial prophylaxis did not significantly decrease symptomatic infections. Prophylaxis was associated with a reduction in asymptomatic bacteriuria among acute patients (<90d after spinal cord injury; P <.05); 1 patient would require 3.7 weeks of treatment on average to prevent 1 asymptomatic infection. For nonacute patients, the reduction approached statistical significance (P =.06). Prophylaxis resulted in an approximately twofold increase in antimicrobial-resistant bacteria. CONCLUSIONS: The regular use of antimicrobial prophylaxis for most patients who have neurogenic bladder caused by spinal cord dysfunction is not supported. A clinically important effect, however, has not been excluded. Future research should focus on randomized trials in those patients who have recurrent UTIs that limit their daily functioning and well-being.

Antibiotic Prophylaxis↗

PubMed2002

Characteristics of eye care practices with managed care contracts.

OBJECTIVES: To describe the variation in practice structure, financial arrangements, and utilization and quality management systems for eye care practices with managed care contracts. STUDY DESIGN: Cross-sectional survey of 88 group and 56 solo eye care practices that contract with 6 health plans affiliated with a national managed care organization. The survey contained modules on practice structure, financial arrangements, utilization management, and quality management. The survey response rate was 85%. RESULTS: Group practices with both ophthalmologists and optometrists were triple the size of ophthalmology-only groups, and 5 times the size of optometry-only groups. Fee-for-service payments were the primary source of group practice revenues, although 60% of groups derived some revenues from capitation payments. Group practices paid their physicians almost exclusively with fee-for-service payments or salary arrangements, with minimal capitation at the individual level. Almost no practices used both capitation and bonuses to compensate providers. Most practices received practice profiles and three fourths were subject to utilization review, which mainly consisted of preauthorization for procedures, tests, or referrals. Nearly all practices used clinical guidelines, protocols, or pathways in managing patients with diabetic retinopathy or glaucoma. Further, nearly all group practices used computerized information systems to assist in delivering care, and most had provider education programs. CONCLUSIONS: Managed care has affected the way eye care providers organize, finance, and deliver healthcare. In general, our findings paint an optimistic picture of eye care practices that contract with managed care organizations. Few practices bear substantial financial risk, and nearly all practices use quality management tools that could help to improve the quality of care.

Capitation Fee↗