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Dive into the research topics where Mark C. Hornbrook is active.

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Featured researches published by Mark C. Hornbrook.


JAMA | 1995

The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of Intervention Techniques

Province Ma; Evan C. Hadley; Mark C. Hornbrook; Lewis A. Lipsitz; Jessica Miller; Cynthia D. Mulrow; Marcia G. Ory; Richard W. Sattin; Mary E. Tinetti; Steven L. Wolf

OBJECTIVE To determine if short-term exercise reduces falls and fall-related injuries in the elderly. DESIGN A preplanned meta-analysis of the seven Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT)--independent, randomized, controlled clinical trials that assessed intervention efficacy in reducing falls and frailty in elderly patients. All included an exercise component for 10 to 36 weeks. Fall and injury follow-up was obtained for up to 2 to 4 years. SETTING Two nursing home and five community-dwelling (three health maintenance organizations) sites. Six were group and center based; one was conducted at home. PARTICIPANTS Numbers of participants ranged from 100 to 1323 per study. Subjects were mostly ambulatory and cognitively intact, with minimum ages of 60 to 75 years, although some studies required additional deficits, such as functionally dependent in two or more activities of daily living, balance deficits or lower extremity weakness, or high risk of falling. INTERVENTIONS Exercise components varied across studies in character, duration, frequency, and intensity. Training was performed in one area or more of endurance, flexibility, balance platform, Tai Chi (dynamic balance), and resistance. Several treatment arms included additional nonexercise components, such as behavioral components, medication changes, education, functional activity, or nutritional supplements. MAIN OUTCOME MEASURES Time to each fall (fall-related injury) by self-report and/or medical records. RESULTS Using the Andersen-Gill extension of the Cox model that allows multiple fall outcomes per patient, the adjusted fall incidence ratio for treatment arms including general exercise was 0.90 (95% confidence limits [CL], 0.81, 0.99) and for those including balance was 0.83 (95% CL, 0.70, 0.98). No exercise component was significant for injurious falls, but power was low to detect this outcome. CONCLUSIONS Treatments including exercise for elderly adults reduce the risk of falls.


JAMA | 2012

Use of diagnostic imaging studies and associated radiation exposure for patients enrolled in large integrated health care systems, 1996-2010

Rebecca Smith-Bindman; Diana L. Miglioretti; Eric Johnson; Choonsik Lee; Heather Spencer Feigelson; Michael J. Flynn; Robert T. Greenlee; Randell Kruger; Mark C. Hornbrook; Douglas W. Roblin; Leif I. Solberg; Nicholas Vanneman; Sheila Weinmann; Andrew E. Williams

CONTEXT Use of diagnostic imaging has increased significantly within fee-for-service models of care. Little is known about patterns of imaging among members of integrated health care systems. OBJECTIVE To estimate trends in imaging utilization and associated radiation exposure among members of integrated health care systems. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of electronic records of members of 6 large integrated health systems from different regions of the United States. Review of medical records allowed direct estimation of radiation exposure from selected tests. Between 1 million and 2 million member-patients were included each year from 1996 to 2010. MAIN OUTCOME MEASURE Advanced diagnostic imaging rates and cumulative annual radiation exposure from medical imaging. RESULTS During the 15-year study period, enrollees underwent a total of 30.9 million imaging examinations (25.8 million person-years), reflecting 1.18 tests (95% CI, 1.17-1.19) per person per year, of which 35% were for advanced diagnostic imaging (computed tomography [CT], magnetic resonance imaging [MRI], nuclear medicine, and ultrasound). Use of advanced diagnostic imaging increased from 1996 to 2010; CT examinations increased from 52 per 1000 enrollees in 1996 to 149 per 1000 in 2010, 7.8% annual increase (95% CI, 5.8%-9.8%); MRI use increased from 17 to 65 per 1000 enrollees, 10% annual growth (95% CI, 3.3%-16.5%); and ultrasound rates increased from 134 to 230 per 1000 enrollees, 3.9% annual growth (95% CI, 3.0%-4.9%). Although nuclear medicine use decreased from 32 to 21 per 1000 enrollees, 3% annual decline (95% CI, 7.7% decline to 1.3% increase), PET imaging rates increased after 2004 from 0.24 to 3.6 per 1000 enrollees, 57% annual growth. Although imaging use increased within all health systems, the adoption of different modalities for anatomic area assessment varied. Increased use of CT between 1996 and 2010 resulted in increased radiation exposure for enrollees, with a doubling in the mean per capita effective dose (1.2 mSv vs 2.3 mSv) and the proportion of enrollees who received high (>20-50 mSv) exposure (1.2% vs 2.5%) and very high (>50 mSv) annual radiation exposure (0.6% vs 1.4%). By 2010, 6.8% of enrollees who underwent imaging received high annual radiation exposure (>20-50 mSv) and 3.9% received very high annual exposure (>50 mSv). CONCLUSION Within integrated health care systems, there was a large increase in the rate of advanced diagnostic imaging and associated radiation exposure between 1996 and 2010.


Journal of Health Economics | 1999

Modeling risk using generalized linear models

David K. Blough; Carolyn W. Madden; Mark C. Hornbrook

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.


The New England Journal of Medicine | 2008

Association between Obesity during Pregnancy and Increased Use of Health Care

Susan Y. Chu; Donald J. Bachman; William M. Callaghan; Evelyn P. Whitlock; Patricia M. Dietz; Cynthia J. Berg; Maureen O'Keeffe-Rosetti; F. Carol Bruce; Mark C. Hornbrook

BACKGROUND In the United States, obesity during pregnancy is common and increases obstetrical risks. An estimate of the increase in use of health care services associated with obesity during pregnancy is needed. METHODS We used electronic data systems of a large U.S. group-practice health maintenance organization to identify 13,442 pregnancies among women 18 years of age or older at the time of conception that resulted in live births or stillbirths. The study period was between January 1, 2000, and December 31, 2004. We assessed associations between measures of use of health care services and body-mass index (BMI, defined as the weight in kilograms divided by the square of the height in meters) before pregnancy or in early pregnancy. The women were categorized as underweight (BMI <18.5), normal (BMI 18.5 to 24.9), overweight (BMI 25.0 to 29.9), obese (BMI 30.0 to 34.9), very obese (BMI 35.0 to 39.9), or extremely obese (BMI > or =40.0). The primary outcome was the mean length of hospital stay for delivery. RESULTS After adjustment for age, race or ethnic group, level of education, and parity, the mean (+/-SE) length of hospital stay for delivery was significantly (P<0.05) greater among women who were overweight (3.7+/-0.1 days), obese (4.0+/-0.1 days), very obese (4.1+/-0.1 days), and extremely obese (4.4+/-0.1 days) than among women with normal BMI (3.6+/-0.1 days). A higher-than-normal BMI was associated with significantly more prenatal fetal tests, obstetrical ultrasonographic examinations, medications dispensed from the outpatient pharmacy, telephone calls to the department of obstetrics and gynecology, and prenatal visits with physicians. A higher-than-normal BMI was also associated with significantly fewer prenatal visits with nurse practitioners and physician assistants. Most of the increase in length of stay associated with higher BMI was related to increased rates of cesarean delivery and obesity-related high-risk conditions. CONCLUSIONS Obesity during pregnancy is associated with increased use of health care services.


Medical Care | 2002

Surveying physicians: do components of the "Total Design Approach" to optimizing survey response rates apply to physicians?

Terry S. Field; Cynthia A. Cadoret; Martin L. Brown; Marvella E. Ford; Sarah M. Greene; Deanna D. Hill; Mark C. Hornbrook; Richard T. Meenan; Mary Jo White; Jane Zapka

Background. Surveys serve essential roles in clinical epidemiology and health services research. However, physician surveys frequently encounter problems achieving adequate response rates. Research on enhancing response rates to surveys of the general public has led to the development of Dillman’s “Total Design Approach“ to the design and conduct of surveys. The impact of this approach on response rates among physicians is uncertain. Objective. To determine the extent to which the components of the total design approach have been found to be effective in physician surveys. Design. A systematic review. Results. The effectiveness of prepaid financial incentives, special contacts, and personalization to enhance response rates in surveys of physicians have been confirmed by the existing research. There is suggestive evidence supporting the use of first class stamps on return envelopes and multiple contacts. The optimum amount for incentives and the number of contacts necessary have not been established. Details of questionnaire design and their impact on response rates have received almost no attention from researchers. Few studies have assessed the usefulness of combinations of components of the total design approach. Conclusions. Despite the number of surveys conducted among physicians, their cost, the level of interest in their findings, and in spite of inadequate response rates, there have been few randomized trials conducted on important aspects of enhancing response in this population. Until this gap has been filled, researchers conducting surveys of physicians should consider including all components of the total design approach whenever feasible.


Journal of Clinical Oncology | 2009

Health-Related Quality of Life Among Long-Term Rectal Cancer Survivors With an Ostomy: Manifestations by Sex

Robert S. Krouse; Lisa J. Herrinton; Marcia Grant; Christopher S. Wendel; Sylvan B. Green; M. Jane Mohler; Carol M. Baldwin; Carmit K. McMullen; Susan M. Rawl; Eric Matayoshi; Stephen Joel Coons; Mark C. Hornbrook

PURPOSE Intestinal stomas can pose significant challenges for long-term (> or = 5 years) rectal cancer (RC) survivors. Specifying common challenges and sociodemographic or clinical differences will further the development of tailored interventions to improve health-related quality of life (HRQOL). PATIENTS AND METHODS This was a matched cross-sectional study of long-term RC survivors conducted in three Kaiser Permanente regions. The mailed questionnaire included the modified City of Hope Quality of Life-Ostomy (mCOH-QOL-Ostomy) and Medical Outcomes Study 36-Item Short-Form Health Survey, version 2 (SF-36v2). Groups surveyed were permanent ostomates (cases) and those who did not require an ostomy (controls). RC survivors were matched on sex, age, and time since diagnosis. Comparisons between groups used regression analysis with adjustment for age, comorbidity score, history of radiation therapy, income, and work status. RESULTS Response rate was 54% (491 of 909). Cases and controls had similar demographic characteristics. On the basis of the mCOH-QOL-Ostomy, both male and female cases had significantly worse social well-being compared with controls, while only female cases reported significantly worse overall HRQOL and psychological well-being. For younger females (< age 75 years), ostomy had a greater impact on physical well-being compared with older females. Based on the SF-36v2, statistically significant and meaningful differences between female cases and controls were observed for seven of the eight scales and on the physical and mental component summary scores. CONCLUSION Men and women report a different profile of challenges, suggesting the need for targeted or sex-specific interventions to improve HRQOL in this population. This may include focus on physical HRQOL for female ostomy survivors younger than age 75.


Medical Care | 1997

The Effect of Increased Prescription Drug Cost-sharing on Medical Care Utilization and Expenses of Elderly Health Maintenance Organization Members

Richard E. Johnson; Michael J. Goodman; Mark C. Hornbrook; Michael B. Eldredge

OBJECTIVES The nature and extent of prescription drug benefits for the elderly are a continuing concern for health-care managers and policy makers. This study examined the impact of increased prescription drug cost-sharing on the drug and medical care utilization and expenses of the elderly. METHODS Two groups of well-insured Medicare risk-based members of a large health maintenance organization (HMO) had their copayments increased in different years during a 3-year period. Four 2-year analysis periods were established for comparing these elderly groups. During one analysis period, copayments did not change in either group. RESULTS Moderate increases of from


Journal of Clinical Epidemiology | 1994

Replicating the chronic disease score (CDS) from automated pharmacy data

Richard E. Johnson; Mark C. Hornbrook; Gregory A. Nichols

1 to


Cancer | 2007

Racial differences in tumor stage and survival for colorectal cancer in an insured population

Chyke A. Doubeni; Terry S. Field; Diana S. M. Buist; Eli J. Korner; Carol Bigelow; Lois Lamerato; Lisa J. Herrinton; Virginia P. Quinn; Gene Hart; Mark C. Hornbrook; Jerry H. Gurwitz; Edward H. Wagner

3, from


eGEMs (Generating Evidence & Methods to improve patient outcomes) | 2014

The HMO Research Network Virtual Data Warehouse: A Public Data Model to Support Collaboration

Tyler R. Ross; Daniel Ng; Jeffrey S. Brown; Roy Pardee; Mark C. Hornbrook; Gene Hart; John F. Steiner

3 to

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Robert S. Krouse

University of Pennsylvania

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Marcia Grant

City of Hope National Medical Center

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