Feasibility and safety of early combined cognitive and physical therapy for critically ill medical and surgical patients: the Activity and Cognitive Therapy in ICU (ACT-ICU) trial.

PURPOSE: Cognitive impairment after critical illness is common and debilitating. We developed a cognitive therapy program for critically ill patients and assessed the feasibility and safety of administering combined cognitive and physical therapy early during a critical illness. METHODS: We randomized 87 medical and surgical ICU patients with respiratory failure and/or shock in a 1:1:2 manner to three groups: usual care, early once-daily physical therapy, or early once-daily physical therapy plus a novel, progressive, twice-daily cognitive therapy protocol. Cognitive therapy included orientation, memory, attention, and problem-solving exercises, and other activities. We assessed feasibility outcomes of the early cognitive plus physical therapy intervention. At 3 months, we also assessed cognitive, functional, and health-related quality of life outcomes. Data are presented as median (interquartile range) or frequency (%). RESULTS: Early cognitive therapy was a delivered to 41/43 (95%) of cognitive plus physical therapy patients on 100% (92-100%) of study days beginning 1.0 (1.0-1.0) day following enrollment. Physical therapy was received by 17/22 (77%) of usual care patients, by 21/22 (95%) of physical therapy only patients, and 42/43 (98%) of cognitive plus physical therapy patients on 17% (10-26%), 67% (46-87%), and 75% (59-88%) of study days, respectively. Cognitive, functional, and health-related quality of life outcomes did not differ between groups at 3-month follow-up. CONCLUSIONS: This pilot study demonstrates that early rehabilitation can be extended beyond physical therapy to include cognitive therapy. Future work to determine optimal patient selection, intensity of treatment, and benefits of cognitive therapy in the critically ill is needed.

Long-term cognitive impairment after critical illness.

BACKGROUND: Survivors of critical illness often have a prolonged and disabling form of cognitive impairment that remains inadequately characterized. METHODS: We enrolled adults with respiratory failure or shock in the medical or surgical intensive care unit (ICU), evaluated them for in-hospital delirium, and assessed global cognition and executive function 3 and 12 months after discharge with the use of the Repeatable Battery for the Assessment of Neuropsychological Status (population age-adjusted mean [±SD] score, 100±15, with lower values indicating worse global cognition) and the Trail Making Test, Part B (population age-, sex-, and education-adjusted mean score, 50±10, with lower scores indicating worse executive function). Associations of the duration of delirium and the use of sedative or analgesic agents with the outcomes were assessed with the use of linear regression, with adjustment for potential confounders. RESULTS: Of the 821 patients enrolled, 6% had cognitive impairment at baseline, and delirium developed in 74% during the hospital stay. At 3 months, 40% of the patients had global cognition scores that were 1.5 SD below the population means (similar to scores for patients with moderate traumatic brain injury), and 26% had scores 2 SD below the population means (similar to scores for patients with mild Alzheimer's disease). Deficits occurred in both older and younger patients and persisted, with 34% and 24% of all patients with assessments at 12 months that were similar to scores for patients with moderate traumatic brain injury and scores for patients with mild Alzheimer's disease, respectively. A longer duration of delirium was independently associated with worse global cognition at 3 and 12 months (P=0.001 and P=0.04, respectively) and worse executive function at 3 and 12 months (P=0.004 and P=0.007, respectively). Use of sedative or analgesic medications was not consistently associated with cognitive impairment at 3 and 12 months. CONCLUSIONS: Patients in medical and surgical ICUs are at high risk for long-term cognitive impairment. A longer duration of delirium in the hospital was associated with worse global cognition and executive function scores at 3 and 12 months. (Funded by the National Institutes of Health and others; BRAIN-ICU ClinicalTrials.gov number, NCT00392795.).

Organisational culture: variation across hospitals and connection to patient safety climate.

CONTEXT: Bureaucratic organisational culture is less favourable to quality improvement, whereas organisations with group (teamwork) culture are better aligned for quality improvement. OBJECTIVE: To determine if an organisational group culture shows better alignment with patient safety climate. DESIGN: Cross-sectional administration of questionnaires. Setting 40 Hospital Corporation of America hospitals. PARTICIPANTS: 1406 nurses, ancillary staff, allied staff and physicians. MAIN OUTCOME MEASURES: Competing Values Measure of Organisational Culture, Safety Attitudes Questionnaire (SAQ), Safety Climate Survey (SCSc) and Information and Analysis (IA). RESULTS: The Cronbach alpha was 0.81 for the group culture scale and 0.72 for the hierarchical culture scale. Group culture was positively correlated with SAQ and its subscales (from correlation coefficient r = 0.44 to 0.55, except situational recognition), ScSc (r = 0.47) and IA (r = 0.33). Hierarchical culture was negatively correlated with the SAQ scales, SCSc and IA. Among the 40 hospitals, 37.5% had a hierarchical dominant culture, 37.5% a dominant group culture and 25% a balanced culture. Group culture hospitals had significantly higher safety climate scores than hierarchical culture hospitals. The magnitude of these relationships was not affected after adjusting for provider job type and hospital characteristics. CONCLUSIONS: Hospitals vary in organisational culture, and the type of culture relates to the safety climate within the hospital. In combination with prior studies, these results suggest that a healthcare organisation's culture is a critical factor in the development of its patient safety climate and in the successful implementation of quality improvement initiatives.

Using real time process measurements to reduce catheter related bloodstream infections in the intensive care unit.

PROBLEM: Measuring a process of care in real time is essential for continuous quality improvement (CQI). Our inability to measure the process of central venous catheter (CVC) care in real time prevented CQI efforts aimed at reducing catheter related bloodstream infections (CR-BSIs) from these devices. DESIGN: A system was developed for measuring the process of CVC care in real time. We used these new process measurements to continuously monitor the system, guide CQI activities, and deliver performance feedback to providers. SETTING: Adult medical intensive care unit (MICU). KEY MEASURES FOR IMPROVEMENT: Measured process of CVC care in real time; CR-BSI rate and time between CR-BSI events; and performance feedback to staff. STRATEGIES FOR CHANGE: An interdisciplinary team developed a standardized, user friendly nursing checklist for CVC insertion. Infection control practitioners scanned the completed checklists into a computerized database, thereby generating real time measurements for the process of CVC insertion. Armed with these new process measurements, the team optimized the impact of a multifaceted intervention aimed at reducing CR-BSIs. EFFECTS OF CHANGE: The new checklist immediately provided real time measurements for the process of CVC insertion. These process measures allowed the team to directly monitor adherence to evidence-based guidelines. Through continuous process measurement, the team successfully overcame barriers to change, reduced the CR-BSI rate, and improved patient safety. Two years after the introduction of the checklist the CR-BSI rate remained at a historic low. LESSONS LEARNT: Measuring the process of CVC care in real time is feasible in the ICU. When trying to improve care, real time process measurements are an excellent tool for overcoming barriers to change and enhancing the sustainability of efforts. To continually improve patient safety, healthcare organizations should continually measure their key clinical processes in real time.

The hemochromatosis C282Y allele: a risk factor for hepatic veno-occlusive disease after hematopoietic stem cell transplantation.

Hepatic veno-occlusive disease (HVOD) is a serious complication of hematopoietic stem cell transplantation (HSCT). Since the liver is a major site of iron deposition in HFE-associated hemochromatosis, and iron has oxidative toxicity, we hypothesized that HFE genotype might influence the risk of HVOD after myeloablative HSCT. We determined HFE genotypes in 166 HSCT recipients who were evaluated prospectively for HVOD. We also tested whether a common variant of the rate-limiting urea cycle enzyme, carbamyl-phosphate synthetase (CPS), previously observed to protect against HVOD in this cohort, modified the effect of HFE genotype. Risk of HVOD was significantly higher in carriers of at least one C282Y allele (RR=3.7, 95% CI 1.2-12.1) and increased progressively with C282Y allelic dose (RR=1.7, 95% CI 0.4-6.8 in heterozygotes; RR=8.6, 95% CI 1.5-48.5 in homozygotes). The CPS A allele, which encodes a more efficient urea cycle enzyme, reduced the risk of HVOD associated with HFE C282Y. We conclude that HFE C282Y is a risk factor for HVOD and that CPS polymorphisms may counteract its adverse effects. Knowledge of these genotypes and monitoring of iron stores may facilitate risk-stratification and testing of strategies to prevent HVOD, such as iron chelation and pharmacologic support of the urea cycle.

Predictors of influenza virus vaccination status in hospitalized children.

OBJECTIVE: To determine predictors of influenza virus vaccination status in children who are hospitalized during the influenza season. METHODS: A cross-sectional study was conducted among children who were hospitalized with fever between 6 months and 3 years of age or with respiratory symptoms between 6 months and 18 years of age. The 1999 to 2000 influenza vaccination status of hospitalized children and potential factors that influence decisions to vaccinate were obtained from a questionnaire administered to parents/guardians. RESULTS: Influenza vaccination rates for hospitalized children with and without high-risk medical conditions were 31% and 14%, respectively. For both groups of children, the vaccination status was strongly influenced by recommendations from physicians. More than 70% of children were vaccinated if a physician had recommended the influenza vaccine, whereas only 3% were vaccinated if a physician had not. Lack of awareness that children can receive the influenza vaccine was a commonly cited reason for nonvaccination. CONCLUSIONS: A minority of hospitalized children with high-risk conditions had received the influenza vaccine. However, parents' recalling that a clinician had recommended the vaccine had a positive impact on the vaccination status of children.

Protocol-driven care in the intensive care unit: a tool for quality.

Advances in organization and patient management in the intensive care unit (ICU) have led to reductions in the morbidity and mortality suffered by critically ill patients. Two such advances include multidisciplinary teams (MDTs) and the development of clinical protocols. The use of protocols and MDTs does not necessarily guarantee instant improvement in the quality of care, but it does offer useful tools for the pursuit of such objectives. As ICU physicians increasingly assume leadership roles in the pursuit of higher quality ICU care, their knowledge and skills in the discipline of quality improvement will become essential.

Using an improvement model to reduce adverse drug events in VA facilities.

BACKGROUND: Adverse drug events cause significant morbidity and mortality in health care. Many adverse drug events are due to medication errors and are preventable. In 1999 and 2000 the Patient Safety Center of Inquiry collaborated with the Institute for Healthcare Improvement (IHI) to implement a quality improvement (QI) project designed to reduce medication errors within the Veterans Administration system. METHODS: During a 6- to 9-month period, interdisciplinary teams that want to achieve much higher levels of performance work on a common aim, under the guidance of faculty, and come together for three 2-day educational and planning sessions. Between these sessions, teams implement some of the suggested changes, measure the results of those changes, and report back to the larger group. RESULTS: During the formal project, teams collected allergy information on more than 20,000 veterans and averted 1,833 medication errors that had the potential to cause adverse events. At 6-month follow-up, the majority of teams remained intact, continued to collect data, and maintained their gains, approximately doubling the results obtained during the formal project. Half of the teams expanded their efforts to other settings, and one-third of the teams expanded beyond their original topics. Returns on investment in the QI effort were substantial. CONCLUSIONS: The results suggest that gains made in organized QI efforts can be maintained for 6 months without additional external support or coaching if team structure and leadership support remain intact. Facilitators of QI efforts should focus on teams that are having difficulty learning new techniques. Finally, this effort appeared to generate cost savings.

Physician enthusiasm as an explanation for area variation in the utilization of knee replacement surgery.

BACKGROUND: Explanations for regional variation in the use of many medical and surgical treatments is controversial. OBJECTIVES: To identify factors that might be amenable to intervention, we investigated the determinants of regional variation in the use of knee replacement surgery. RESEARCH DESIGN: We examined the effect of the following factors: characteristics and opinions of surgeons; family physicians and rheumatologists; patients' severity of disease before knee replacement; access to knee-replacement surgery; surgeons' use of other surgical treatment; and county population characteristics. OUTCOMES MEASURE: County utilization rates of knee replacement in Ontario, Canada. RESULTS: Counties that had higher rates of knee replacement had older patients (P = 0.0001), higher percentage of medical school affiliated hospital beds (P = 0.04), with more male (P = 0.02) non-North American trained referring physicians (P = 0.002) and orthopedic surgeons who had higher propensities to operate and better perceptions of outcome (P = 0.0001). CONCLUSIONS: After controlling for population characteristics and access to care (including the number of hospital beds, and the density of orthopaedic and referring physicians), orthopaedic surgeons' opinions or enthusiasm for the procedure was the dominant modifiable determinant of area variation. Thus, research needs to focus on the opinions of surgeons which may be important in reducing regional variation for knee replacement.

Management of osteoarthritis of the knee by primary care physicians.

BACKGROUND: Most patients with osteoarthritis (OA) are treated by primary care physicians (in this article, primary care physicians are family physicians and general internists). OBJECTIVE: To describe and compare the self-reported practice patterns of family physicians and general internists for the evaluation and management of severe OA of the knee, including factors that might influence referral for total knee replacement. DESIGN, SETTING, AND PARTICIPANTS: A survey was developed and mailed to randomly selected community family physicians and general internists practicing in Indiana. MAIN OUTCOME MEASURE: Self-reported physician practice patterns regarding OA of the knee. RESULTS: Physical examination was the most common method of evaluating OA of the knee. Family physicians were more likely to examine for crepitation, joint stability, and quadriceps muscle strength than were general internists (P<.05). Patients with OA of the knee treated by family physicians were more likely to receive nonsteroidal anti-inflammatory drugs or oral corticosteroids and were less likely to receive aspirin, acetaminophen, or narcotics compared with patients treated by general internists. Six patient characteristics were rated as positive factors favoring a referral for possible total knee replacement, 8 characteristics were rated as negative, and 5 were rated as not a factor in the decision about referral. CONCLUSIONS: Results from this study suggest that additional research is needed to determine the evaluative techniques for OA of the knee that provide the most useful information for management decisions, the management techniques that maximize patient outcomes, and the criteria that should be used to select patients who would benefit most from referral for possible total knee replacement.

Revision rates after knee replacement in the United States.

OBJECTIVES: Each year approximately 100,000 Medicare patients undergo knee replacement surgery. Patients, referring physicians, and surgeons must consider a variety of factors when deciding if knee replacement is indicated. One factor in this decision process is the likelihood of revision knee replacement after the initial surgery. This study determined the chance that a revision knee replacement will occur and which factors were associated with revision. METHODS: Data on all primary and revision knee replacements that were performed on Medicare patients during the years 1985 through 1990 were obtained. The probability that a revision knee replacement occurred was modeled from data for all patients for whom 2 full years of follow-up data were available. Two strategies for linking revisions to a particular primary knee replacement for each patient were developed. Predictive models were developed for each linking strategy. ICD-9-CM codes were used to determine hospitalizations for primary knee replacement and revision knee replacement. RESULTS: More than 200,000 hospitalizations for primary knee replacements were performed, with fewer than 3% of them requiring revision within 2 years. The following factors increase the chance of revision within 2 years of primary knee replacement: (1) male gender, (2) younger age, (3) longer length of hospital stay for the primary knee replacement, (4) more diagnoses at the primary knee replacement hospitalization, (5) unspecified arthritis type, (6) surgical complications during the primary knee replacement hospitalization, and (7) primary knee replacement performed at an urban hospital. CONCLUSIONS: Revision knee replacement is uncommon. Demographic, clinical, and process factors were related to the probability of revision knee replacement.

Use of the rectal examination on children with acute abdominal pain.

The purpose of this study was to determine the frequency with which general pediatricians perform a rectal examination on children with a complaint of acute abdominal pain and to determine factors associated with performing a rectal examination. Children were eligible for the study if they were 2 to 12 years of age and presented to the clinic or emergency department of a municipal teaching hospital with a complaint of abdominal pain of less than or equal to three days' duration. Measured variables included demographic characteristics and presenting signs and symptoms. For each patient, a clinical reviewer (1) assigned a final diagnosis, (2) determined whether a rectal examination had been performed, and (3) assessed the clinical contribution of the rectal examination findings. For 1,140 children presenting for a nonscheduled visit with acute abdominal pain, a rectal examination was performed on 4.9% (56/1,140). Using multiple logistic regression, children were more likely to have a rectal examination performed if they had abdominal tenderness (odds ratio [OR] = 3.3 and 95% confidence interval [CI], 1.8 to 6.0), a history of constipation (OR = 6.0 and 95% CI, 2.3 to 15.3), or a history of rectal bleeding (OR = 9.1 and 95% CI, 2.9 to 29). Children were less likely to have had a rectal examination performed if they presented with associated symptoms of cough (OR = 0.32 and 95% CI, 0.14 to 0.74), headache (OR = 0.15 and 95% CI, 0.05 to 0.46), or sore throat (OR = 0.28 and 95% CI, 0.08 to 0.91). The final diagnoses of 12 children who had clinically contributory findings on rectal examination included: constipation (5), gastroenteritis (3), appendicitis (2), abdominal adhesions (1), and abdominal pain of unclear etiology (1). General pediatricians infrequently perform a rectal examination on children who present with a complaint of acute abdominal pain. Clinical factors affect the likelihood of whether a rectal examination is performed.

Comparison of general internists, family physicians, and rheumatologists managing patients with symptoms of osteoarthritis of the knee.

OBJECTIVE: To evaluate the nature, risks, and benefits of osteoarthritis (OA) management by primary care physicians and rheumatologists. METHODS: Subjects were 419 patients followed for symptoms of knee OA by either a specialist in family medicine (FM) or general internal medicine (GIM) or by a rheumatologist (RH). Management practices were characterized by in-home documentation by a visiting nurse of drugs taken to relieve OA pain or to prevent gastrointestinal side effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and by patient report (self-administered survey) of nonpharmacologic treatments. Changes in outcomes (knee pain and physical function) over 6 months were measured with the Western Ontario and McMaster Universities Osteoarthritis Index. RESULTS: Patients of RHs were 2-3 years older (P = 0.035) and tended to exhibit greater radiographic severity of OA (P = 0.064) and poorer physical function (P = 0.076) at baseline than the other 2 groups. In all 3 groups, knee pain and physical function improved slightly over 6 months; however, between-group differences were not significant. Compared to drug management of knee pain by FMs or RHs, that by the GIMs was distinguished by greater utilization of acetaminophen and nonacetylated salicylates (P = 0.008), lower prescribed doses of NSAIDs (P = 0.007), and, therefore, lower risk of iatrogenic gastroenteropathy (P < 0.001). In contrast, patients of RHs were more likely than those of FMs and GIMs to report that they had been instructed in use of isometric quadriceps and range-of-motion exercises (P < or = 0.001), application of heat (P = 0.051) and cold (P < 0.001) packs, and in the principles of joint protection (P = 0.016). Neither physician specialty nor specific management practices accounted for variations in patient outcomes. CONCLUSION: This observational study identified specialty-related variability in key aspects of the management of knee OA in the community (i.e., frequency and dosing of NSAIDs, use of nonpharmacologic modalities) that bear strong implications for long-term safety and cost. However, changes in knee pain and function over 6 months were unrelated to variations in management practices.

Effect of health care system factors on test ordering.

OBJECTIVE: To determine the effect of the emergency department (ED) environment and other health care system factors on test ordering for children with acute abdominal pain. METHODS: We reviewed the encounter records of 1140 consecutive children seen in either the pediatric clinic or ED of an inner-city teaching hospital with a complaint of acute abdominal pain (< 72 hours). In the ED and the clinic, patients were seen by medical students, pediatric residents, and general pediatric faculty members. Measured data on test ordering included the number of tests ordered and the type of tests ordered; specifically examined were the throat culture, urinalysis or urine culture, and chest radiograph. Measured health care system factors included (1) encounter location; (2) resident involvement and level of training; (3) student involvement; and (4) faculty member's years of experience and sex. RESULTS: Of the 1140 children, 117 (10.2%) were seen in the ED, 531 (47.1%) were seen by a resident, 344 (30.2%) were seen by a medical student, and 195 (17.1%) were seen by a faculty member with more than 10 years of clinical pediatric experience. After controlling for initial signs and symptoms in multiple logistic regression, a child treated in the ED was no more likely to have had tests ordered than one who was treated in the clinic. Neither resident involvement nor resident training level affected test ordering. Except for decreasing the likelihood of having a urinalysis or urine culture ordered (odds ratio [OR] = 0.30; 95% confidence interval [CI], 0.15-0.63), student involvement did not affect test ordering. Also, except for decreasing the likelihood of having a throat culture ordered (OR = 0.45; 95% CI, 0.25-0.83), being seen by a pediatrician with more than 10 years of experience did not affect test ordering. Children seen by female physicians were more likely (OR = 2.41; 95% CI, 1.57-3.70) to have at least 1 test ordered. CONCLUSIONS: For children seen for a complaint of acute abdominal pain, we found little evidence that test ordering is affected by encounter location, resident involvement, student involvement, or faculty member experience.

Clinical outcomes of children with acute abdominal pain.

OBJECTIVE: To determine the prevalence, associated symptoms, and clinical outcomes of children presenting for a nonscheduled visit with acute abdominal pain. DESIGN: Historical cohort. SETTING: Inner-city teaching hospital. PARTICIPANTS: A total of 1141 consecutive children, ages 2 to 12, presenting for a nonscheduled visit (clinic or emergency department) with a complaint of nontraumatic abdominal pain of < or = 3 days' duration were identified through a manual chart review. MEASUREMENTS: Collected data included: 1) demographic characteristics, 2) presenting signs and symptoms, 3) records from the hospital record for all children who returned within 10 days for follow-up, 4) test results, and 5) telephone follow-up. A clinical reviewer used the data to assign a final diagnosis to each patient. RESULTS: The prevalence of children presenting with abdominal pain of < or = 3 days' duration was 5.1%. The most common associated symptoms were history of fever (64%), emesis (42.4%), decreased appetite (36.5%), cough (35.6%), headache (29.5%), and sore throat (27.0%). The six most prevalent final diagnoses, accounting for 84% of all final diagnoses, were upper respiratory infection and/or otitis (18.6%), pharyngitis (16.6%), viral syndrome (16.0%), abdominal pain of uncertain etiology (15.6%), gastroenteritis (10.9%), and acute febrile illness (7.8%). Approximately 1% of children required surgical intervention (10/12 for appendicitis). Approximately 7% of children returned within 10 days for reevaluation of their illness; on return, 11 had treatable medical diseases and 4 had diseases requiring surgical intervention. CONCLUSIONS: An acute complaint of abdominal pain in children occurs in 5.1% of nonscheduled visits, is frequently accompanied by multiple complaints, and is usually attributed to a self-limited disease. Close follow-up will identify the 1% to 2% who proceed to have a more serious disease process. This epidemiologic data will aid clinic-based physicians who manage children with acute abdominal pain.

Risk factors for delirium tremens development.

OBJECTIVE: To identify clinical characteristics associated with inpatient development of delirium tremens so that future treatment efforts can focus on patients most likely to benefit from aggressive therapy. DESIGN: Retrospective cohort study among patients discharged with diagnoses related to alcohol abuse. SETTING: University-affiliated inner-city hospital. PATIENTS/PARTICIPANTS: Two hundred consecutive patients discharged between June 1991 and August 1992 who underwent evaluation and treatment for alcohol withdrawal or detoxification. MEASUREMENTS AND MAIN RESULTS: Mean age was 41.9 years, 85% were male, 57% were white and 84% were unmarried. Forty-eight (24%) of the patients developed delirium tremens during hospitalization. Bivariate analysis indicated that those who developed delirium tremens were more likely to be African-American, unemployed, and homeless, and were more likely to have gone more days since their last drink, and to have concurrent acute medical illness, high admission blood urea nitrogen level and respiratory rate, and low admission albumin level and systolic blood pressure. In multiple logistic regression analyses, patients who developed delirium tremens were more likely to have gone more days since their last drink (odds ratio [OR] 1.3; 95% confidence interval [CI] 1.09, 1.61) and to have concurrent acute medical illness (OR 5.1; 95% CI 2.07, 12.55). These risk factors were combined for assessment of their ability to predict the occurrence of delirium tremens. If no factors were present, 9% developed delirium tremens; if one factor was present, 25% developed delirium tremens; and if two factors were present, 54% developed delirium tremens. CONCLUSIONS: Inpatient development of delirium tremens was common among patients treated for alcohol detoxification or withdrawal and correlated with several readily available clinical variables.

Demographic variation in the rate of knee replacement: a multi-year analysis.

OBJECTIVE: The aim of this study is to describe the practice variation of knee replacements (KRs) in the elderly ( > or = 65) over time from 1985-1990 in terms of the number of primary, bilateral, and revision KRs; the extent of large area variation in performance rates; and the degree to which demographic variables are the determinants of area rates. DATA SOURCES/STUDY SETTING: Data analyzed are from every hospital in the United States that performed a KR on a Medicare patient during the study period. Data were obtained from the MEDPAR, HISKEW, and denominator files of the Medicare Statistical System. STUDY DESIGN: This is a cohort study of all Medicare beneficiaries who received a KR between 1985 and 1990. The dependent variable in the analyses was the count of the KRs performed in each area. DATA COLLECTION/EXTRACTION METHODS: This is a population-based sample of Medicare enrollees in the United States. All hospitalizations for Medicare-reimbursed KRs were included in the initial data set. Exclusion criteria were used to identify the Medicare covered population with a definite KR. These criteria resulted in 7.3 percent exclusions and a final set of 414,079 KR hospitalizations. PRINCIPAL FINDINGS: The number of Medicare-funded KRs increased in each of the study years corresponding to an annual rate of increase of 18.45 percent. The likelihood of receiving a KR was a function of age, gender, and race. For each year, KRs were almost-twice as likely to be performed on women than on men. The odds of whites getting the surgery were over 1.5 times greater than for blacks. Even after adjusting for demographic factors, significant regional variation remained. CONCLUSIONS: Much about area variation and the rate of growth in KR rates remains unexplained. For answers to emerge, better data and different types of studies are required.