Skip Navigation U.S. Department of Health and Human Services
Agency for Healthcare Research Quality
Archive print banner

Research Briefs

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to for current information.

Asplin, B.R., Flottemesch, T.J., and Gordon, B.D. (2006). "Developing models for patient flow and daily surge capacity research." (AHRQ grant HS13007). Academic Emergency Medicine 13, pp. 1109-1113.

Between 1993 and 2003, visits to U.S. emergency departments (EDs) jumped 26 percent to a total of 114 million visits a year. At the same time, the number of U.S. EDs decreased by more than 400 and nearly 200,000 inpatient hospital beds were taken out of service. This clearly diminished the capacity of U.S. EDs to handle a daily surge of patients. Examining the daily surge capacity of U.S. EDs is a new area of research. The authors of this paper propose two models that have potential applications for both daily surge capacity and hospital-wide patient flow research. The first model quantitatively describes the dynamic nature of ED census to enable short-term forecasts of ED census, and illustrates the effect of unexpected surges in patient demand. The second model describes a theoretical approach for understanding the relationship between ED length of stay and the quality of patient care.

Burke, L.E., Kim, Y., Senuzun, F., and others (2006). "Evaluation of the shortened cholesterol-lowering diet self-efficacy scale." (AHRQ grant HS08891). European Journal of Cardiovascular Nursing 5, pp. 264-274.

Less than half of adults with elevated cholesterol levels follow the recommended dietary guidelines to reduce their serum cholesterol levels. Persons who expect personal achievement or mastery (self-efficacy) and successful outcomes are more likely to initiate a behavior such as improved diet. The authors of this study reexamined and shortened the original 57-item Cholesterol-Lowering Diet Self-Efficacy Scale (CLDSES). A sample of 238 patients being treated for high cholesterol completed the CLDSES, the Connor Diet Habit Survey, and a 3-day food record. Sensitivity (76 percent) and specificity (63 percent) for the CLDSES short form were good, with 88 percent positive predictive value for patient adherence to a cholesterol-lowering diet.

Chen, Y-H. and Zhou, X-H. (2006). "Interval estimates for the ratio and differences of two lognormal means." (AHRQ grant HS13105). Statistics in Medicine 25, pp. 4099-4113.

Health research often gives rise to data that follow lognormal distributions. For example, researchers are likely to be interested in estimating the difference or ratio of the population means. Several methods have been proposed for providing confidence intervals for these parameters; however, it is not clear which techniques are most appropriate, or how their performance might vary. Methods for the difference of means have not been adequately explored, note the authors of this paper. They discuss five methods of analysis, including two methods based on the long-likelihood ratio statistic and a generalized pivotal approach. They also discuss the results of a series of computer simulations. Finally, they apply the techniques to a real example.

Chretien, J-P., Coresh, J., Berthier-Schaad, Y., and others (2006). "Three single-nucleotide polymorphism in LPA account for most of the increase in lipoprotein(a) level elevation in African Americans compared with European Americans." (AHRQ grant HS08365). Journal of Medical Genetics 43, pp. 917-923.

These researchers used the heritable coronary heart disease risk factor lipoprotein (Lp(a)) level as a useful case study of between-population variation. They examined serum Lp(a) and isoform measurements in 534 European Americans and 249 African Americans who participated in an end-stage renal disease study. They also genotyped 12 Lp(a) sequence variants. Isoform-adjusted Lp(a) level was over two-fold higher among African Americans than European Americans. Three single-nucleotide polymorphisms were independently associated with Lp(a) level; however, all had a frequency of less than 20 percent in one or both populations. The authors conclude that multiple low-prevalence alleles in Lp(a) can account for the large between-population difference in serum Lp(a) levels between European Americans and African Americans.

Cooper, W.O., Arbogast, P.G., Ding, H., and others (2006, March). "Trends in prescribing of antipsychotic medications for U.S. children." (AHRQ grant HS10384). Ambulatory Pediatrics 6, pp. 79-83.

Pediatric prescriptions for antipsychotics jumped five-fold from 1995 to 2002. Based on analysis of data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey, researchers found that antipsychotic prescribing increased from 8.6 per 1,000 U.S. children in 1995-1996 to 39.4 per 1,000 in 2001-2002. Rates were similar for children age 2 to 12 years and 13 to 18 years; however, overall prescribing rates were higher for children age 13 to 18 years. Two-thirds of prescriptions were for males.

Attention deficit/hyperactivity disorder and conduct disorder accounted for 29 percent, and affective disorders (bipolar disorder/depression) accounted for an additional 23.6 percent of medical visits in which an antipsychotic was prescribed. These are conditions for which antipsychotics have not been carefully studied in children. Conditions for which antipsychotics have been studied in children (schizophrenia/psychosis, Tourette's syndrome, and autism/mental retardation) accounted for 26 percent of all antipsychotic prescriptions. Nearly one-third (32.4 percent) of antipsychotic prescriptions were associated with visits to clinicians who were not mental health specialists.

Johansson, P., Jacobsen, C., and Buchwald, D. (2006, Autumn). "Perceived discrimination in health care among American Indians/Alaska Natives." (AHRQ grant 10854). Ethnicity & Disease 16, pp. 766-771.

This study found that American Indian and Alaska Native (AI/AN) were the racial group most likely to report discrimination in health care. AI/AN who identified as both AI/AN and white were twice as likely to perceive discrimination as whites. A telephone survey of adults in the 2001 California Health Interview Survey found that overall 7.1 percent of the AI/AN group, 8.8 percent of the AI/AN plus white group, 5.6 percent of blacks, 4.3 percent of whites, and 2.6 percent of Asian Americans felt discriminated against at some point during the past year of care.

After adjusting for demographic and insurance-related factors, which can also affect discrimination, the AI/AN plus white group was twice as likely and Asian Americans were half as likely to perceive discrimination as whites. More than 20 percent of AI/AN, black, and Asian American respondents reporting discrimination cited race as the sole reason compared with less than 10 percent of AI/AN plus white and white respondents. AI/AN plus white (27 percent) and white (32 percent) groups were more likely to cite insurance as the sole reason for discrimination than were AI/AN (15 percent), blacks (19 percent), and Asian Americans (20 percent).

Lautenbach, E., Tolomeo, P., Mao, X., and others (2006, November). "Duration of outpatient fecal colonization due to Escherichia coli isolated with decreased susceptibility to fluoroquinolones: Longitudinal study of patients recently discharged from the hospital." (AHRQ grant HS10399). Antimicrobial Agents and Chemotherapy 50(11), pp. 3939-3943.

A growing number of infections due to Escherichia coli have become resistant to fluroquinolone antibiotics in recent years. This study examined the duration of outpatient fecal colonization due to E. coli with decreased susceptibility to fluorquinolones among 10 patients. The median duration of colonization following hospital discharge was 80 days. Colonization was longer for isolates demonstrating organic-solvent tolerance than for isolates that were not organic-solvent tolerant (151 vs. 29 days). Colonization was not associated with other resistance mechanisms, demographics, or antibiotic use.

Leape, L.L., Rogers, G., Hanna, D., and others (2006, August). "Developing and implementing safe practices: Voluntary adoption through statewide collaboratives." (ARHQ grant HS11928). Quality and Safety in Health Care 15, 289-295.

Researchers found that if clinical teams of frontline caregivers receive support from hospital leadership, they can develop creative methods for improving teamwork and communication that are critical to patient safety. Hospitals participating in 2 voluntary State collaboratives improved safety by developing multiple subpractices for 2 of the 30 safe practices required by the Joint Commission for the Accreditation of Healthcare Organizations (JCAHO). The State of Massachusetts selected two safe practices to be implemented in hospitals before they were mandated by JCAHO—reconciling medications and timely and reliable communication of critical test results.

A multistakeholder advisory group selected the two practices, and developed the operational details and strategies for implementation, with the advice of content experts. A Statewide collaborative model of hospitals with hospital CEO "buy-in" was used to facilitate implementation of the practices. Each hospital team had access to experts, a toolkit containing recommendations, a change package, and implementation strategies. Fifty percent of reconciling medication teams and 65 percent of communicating critical test result teams achieved partial implementation of the practices. Twenty percent of teams from each achieved full implementation. The prior development of subpractices, recommendations, and implementation strategies was essential for the hospital teams.

Marcantonio, E.R., O'Malley, A.J., Murkofsky, R.L., and others (2006, December). "Derivation and confirmation of scales measuring medical directors' attitudes about the hospitalization of nursing home residents." (AHRQ grant HS10645). Journal of Aging and Health 18(6), pp. 869-884.

These researchers sought to derive and confirm scales measuring medical directors' attitudes about hospitalization of nursing home residents. They surveyed nursing facility medical directors about the necessity of hospitalizing residents for eight clinical conditions. They then compared the ratings to those obtained from an expert panel to derive a relative hospitalization score. The score demonstrated that medical directors were slightly less likely to recommend hospitalization than expert panel physicians. The medical directors identified multiple determinants of hospitalization for nursing facility residents across several domains. Their hospitalization decisions were complex and involved clinical and nonclinical factors.

Moore, K., Roubideaux, Y., Noonan, C., and others (2006, Autumn). "Measuring the quality of diabetes care in urban and rural Indian health programs." (AHRQ grant 10854). Ethnicity & Disease 16, pp. 772-777.

The authors of this study reviewed medical record data as part of the Indian Health Service Diabetes Care and Outcomes Audit in 2002. They compared Indian health facilities' adherence to diabetes care guidelines when treating all 710 American Indian and Alaska Native (AI/AN) patients at 17 urban Indian health clinics and a random sample of 1,420 AI/AN patients from 225 rural Indian health facilities. They specifically examined urban and rural differences in adherence to nine indicators of diabetes care quality: annual eye, foot, and dental exams; annual urinalysis; annual blood glucose and cholesterol tests; and influenza and pneumonia immunizations.

Urban patients were more likely than rural patients to have received formal diabetes education in the past 12 months (76 vs. 62 percent). However, there were no significant differences in completion of laboratory tests and immunizations between patients at rural and urban clinics. Patients seen at rural facilities were significantly more likely to receive a dental exam (41 vs. 19 percent). After adjusting for other factors affecting outcomes, blood glucose levels, blood pressure, and cholesterol levels were similar for urban and rural patients. Overall, rates of adherence to nationally recommended care guidelines for AI/AN health programs were comparable to or surpassed rates described for the general population.

Mulkern, R.V., Barnes, A.S., Haker, S.J., and others (2006). "Biexponential characterization of prostate tissue water diffusion decay curves over an extended b-factor range." (AHRQ grant HS13234). Magnetic Resonance Imaging 24, pp. 563-568.

The authors of this study performed detailed measurements of water diffusion within the prostate over an extended b-factor range to assess whether the standard assumption of monoexponential signal delay was appropriate in the prostate. From nine men undergoing prostate magnetic resonance staging examinations, they scanned a 1.5 T, a single 10-mm-thick axial slice with a line scan diffusion imaging sequence in which 14 equally spaced b factors from 5 to 3,500 s/mm2 were sampled along 3 orthogonal diffusion sensitization directions in 6 minutes. They concluded that a monoexponential model for water diffusion decay in prostate tissue is inadequate when a large range of b factors is sampled, and that biexponential analyses are better suited for characterizing prostate diffusion decay curves.

Shechter, S.M., Schaefer, A.J., Braithwaite, R.S., and Roberts, M.S. (2006). "Increasing the efficiency of Monte Carlo cohort simulations with variance reduction techniques." (AHRQ grant HS09694). Medical Decision Making 26, pp. 550-553.

Monte Carlo (MC) cohort simulations are typically used in medical decisionmaking research, for example, to assess the mean costs and quality-adjusted life years for heart disease or HIV. The authors of this paper discuss techniques for MC cohort simulations that reduce the number of simulation replications required to achieve a given degree of precision for various output measures. Known as variance reduction techniques, they are often used in industrial engineering and operations research models, but they are seldom used in medical models. However, most MC cohort simulations are well suited to the implementation of these techniques, note the authors. They discuss the cost of implementing MC cohort simulations versus the benefit of reduced replications.

Reade, M.C., and Angus, D.C. (2006). "PAC-Man: Game over for the pulmonary artery catheter?" (AHRQ grant HS11620). Critical Care 10(1), pp. 303-305, 2006.

The pulmonary artery catheter (PAC) has been used to monitor the hemodynamics (cardiac output) of critically ill patients for the past 30 years. Recently, doubts have been raised about its benefits and safety, but a new study found no clear evidence of benefit or harm in managing critically ill patients with a PAC. Until a superior alternative is found, the decision to insert a PAC should be much more selective than in the past and perhaps also involve discussion with the patient or family, suggest the authors.

A study of 1,014 patients at 65 British Intensive Care Units (ICUs) whose physicians said should be managed using invasive hemodynamic monitoring showed no difference in hospital mortality between patients managed with or without a PAC (68 vs. 66 percent). Complications associated with insertion of a PAC were noted in 10 percent of individuals in whom the device was placed, but none were considered fatal. Complications were not recorded in the non-PAC group, so no conclusions could be reached regarding the relative safety of the PAC.

Of patients randomized to receive either a PAC or no monitor of cardiac output, mortality was 71 percent vs. 66 percent. Of patients randomized in ICUs, allowing the possibility of an alternative monitor of cardiac output, mortality was 68 percent for PAC patients vs. 66 percent for those using alternative monitors. Despite no clear evidence of benefit or harm, PAC use continues, with no standardized agreement about what represents appropriate use.

Tsao, J.C., Dobalian, A., Wiens, B.A., and others (Winter 2006). "Posttraumatic stress disorder in rural primary care: Improving care for mental health following bioterrorism." (AHRQ grant HS14355). The Journal of Rural Health 22(1), pp. 78-82.

Bioterrorist attacks generate fear and uncertainty and contribute to postraumatic stress disorder (PTSD). The authors of this article emphasize the need to educate rural primary care providers on how to manage mental health needs in the event of bioterrorist attacks or other public health disasters. Prior experience with natural disasters suggests that first responders typically focus on immediate medical trauma or injury. After they leave the community, rural primary care providers continue to manage mental health care needs.

The researchers recommend that public health agencies work with rural primary care providers and mental health professionals to develop educational interventions focused on PTSD and other mental disorders, as well as algorithms for assessment, referral, and treatment of postevent psychological disorders or somatic complaints. This collaboration will help ensure the availability, continuity, and delivery of quality mental health care for rural residents following bioterrorism and other public health emergencies.

Westfall, J. M., Van Vorst,R.F., McGloin, J., and Selker, H.P. (2006, March). "Triage and diagnosis of chest pain in rural hospitals: Implementation of the ACI-TIPI in the High Plains Research Network." (AHRQ grant HS11003). Annals of Family Medicine 4(2), pp. 153-158.

This study found that rural emergency department (ED) physicians appropriately diagnose and triage chest pain patients with suspected heart attack even without the use of the Acute Cardiac Ischemia Time-Insensitive Predictive Instrument (ACI-TIPI). The ACI-TIPI prints the probability (0 to 100 percent) that the patient is truly suffering acute cardiac ischemia on the header of the standard electrocardiogram (ECG) interpretation report. The ACI-TIPI has been shown to improve the diagnostic accuracy and triage of chest pain patients in urban and suburban EDs.

The researchers taught ED staff at 10 rural hospitals in the High Plains Practice Research Network how to use new ECG machines over a 3-month period, and conducted the trial during the next 10 months. Each month the hospitals alternated between control (ACI-TIPI off, with just the standard ECG interpretation report produced) and intervention (ACI-TIPI on), when triaging ED patients with chest pain. The ACI-TIPI did not significantly change diagnostic accuracy (86.8 percent with it off and 89 percent with it on), hospitalization of patients with acute ischemia, or the transfer rate of heart attack patients to a tertiary care hospital. The researchers note that a larger rural study may provide a sample sufficient to detect significant changes in triage and diagnostic accuracy with the use of the ACI-TIPI.

Return to Contents

AHRQ Publication No. 07-0027
Current as of April 2007


The information on this page is archived and provided for reference purposes only.


AHRQ Advancing Excellence in Health Care