Strategies for primary and secondary prevention of Lyme disease.

Lyme disease (borreliosis) incidence continues to increase despite a growing knowledge of primary and secondary prevention strategies. Primary prevention aims to reduce the risk of tick exposure and thereby decrease the incidence of new Lyme disease cases. Secondary prevention targets the development of disease or reduces disease severity among people who have been bitten by infected ticks. Numerous prevention strategies are available, and although they vary in cost, acceptability and effectiveness, uptake has been universally poor. Research in areas where Lyme disease is endemic has demonstrated that despite adequate knowledge about its symptoms and transmission, many people do not perform behaviors to reduce their risk of infection. New prevention strategies should aim to increase people's confidence in their ability to carry out preventive behaviors, raise awareness of desirable outcomes, and aid in the realization that the necessary skills and resources are available for preventive measures to be taken. In this article we evaluate the prevention and treatment strategies for Lyme disease, and discuss how these strategies can be implemented effectively. As many patients with Lyme disease develop arthritis and are referred to rheumatologists it is important that these health-care providers can educate patients about disease-prevention strategies.

Determinants of discharge destination following elective total hip replacement.

OBJECTIVE: To identify the factors associated with discharge to an inpatient rehabilitation facility versus discharge directly to home after elective total hip replacement (THR). METHODS: Data were obtained from a medical record review and a cross-sectional survey of a population-based cohort of patients who received elective primary or revision THR in 1995. Postoperative functional status was measured as the ability to walk independently prior to discharge. A multivariate regression model was developed with discharge to an inpatient rehabilitation facility versus directly to home as the dependent variable. The model adjusted for demographic characteristics, socioeconomic features, and several preoperative and postoperative clinical factors. RESULTS: We included 1,276 patients age 65-94 years in the analysis. Of these, 58% were discharged from the acute care hospital to a rehabilitation facility. The cohort had mean age of 73 years; 96% were white; 62% were female; 32% were living alone; 38% had an annual income less than $20,000; and 78% were unable to walk independently in the hospital before discharge. For primary THR patients, multivariate analysis showed a significant association between being discharged to a rehabilitation facility and being unable to walk at discharge, older age, obesity, and living alone. For revision THR patients, multivariate analysis also showed a significant association between being discharged to a rehabilitation facility and being unable to walk at discharge. CONCLUSION: In a large population-based sample, postoperative functional status, age, obesity, and social support all influenced the discharge destination following elective THR.

Utilization of low-volume hospitals for total hip replacement.

OBJECTIVE: To identify factors associated with utilization of low-volume hospitals for total hip replacement (THR) and to estimate differences in the distances that Medicare beneficiaries had to travel to reach low- or high-volume hospitals. METHODS: We studied a population-based sample of 1,146 Medicare beneficiaries who underwent elective THR in 1995. Using multiple data sources including medical record review, Medicare claims data, 1990 Census data, and a patient survey, we examined factors independently associated with utilization of low-volume hospitals for elective THR. We estimated the magnitude of difference in distances for patients undergoing THR in low- and high-volume hospitals. We determined the distance between each patient's residence and the treating hospital using MapQuest. RESULTS: Rural residency, low income, and low educational attainment, as well as belief in the importance of convenient location in the choice of hospital, were associated with higher utilization of low-volume hospitals. Rural and suburban patients who went to low-volume hospitals traveled much less than patients operated upon in high-volume centers. CONCLUSION: Policies aimed at restricting THR to high-volume centers would differentially affect poor, less educated, and rural patients. Voluntary efforts to shift THR to high-volume centers should involve educating these patients and their referring physicians about differences in both short-term and longer-term outcomes between high- and low-volume centers.

Association of hospital and surgeon volume of total hip replacement with functional status and satisfaction three years following surgery.

OBJECTIVE: To evaluate whether hospital volume and surgeon volume of total hip replacements (THRs) are associated with patient-reported functional status and satisfaction with surgery 3 years postoperatively. METHODS: We performed a population-based cohort study of a stratified random sample of Medicare beneficiaries who underwent elective primary or revision THR in Ohio, Pennsylvania, or Colorado in 1995. The primary outcomes were the self-reported Harris hip score and a validated scale measuring satisfaction with the results of surgery. Both outcomes were assessed 3 years postoperatively. Hospital volume was defined as the aggregate number of elective primary and revision THRs performed on Medicare beneficiaries in the hospital in 1995. High-volume hospitals were defined as those in which >100 such procedures are performed annually, and low-volume centers were defined as those in which 12 procedures per year. CONCLUSION: Hospital volume and surgeon volume have little effect on 3-year functional outcome following THR, after adjusting for patient sociodemographic and select clinical characteristics. However, satisfaction with primary THR is greater among patients who underwent surgery in high-volume centers, and satisfaction with revisions is greater among patients whose operations were performed by higher-volume surgeons. Referring clinicians should incorporate these findings into their discussion of referral choices with patients considering THR. Conclusions regarding the effect of volume on longevity of the implants must await longer-term followup studies. Finally, further research is warranted to better understand the association between hospital and surgeon procedure volume and patient satisfaction with surgery.

Incidence rates of dislocation, pulmonary embolism, and deep infection during the first six months after elective total hip replacement.

BACKGROUND: The lengths of acute hospital stays following total hip replacement have diminished substantially in recent years. As a result, a greater proportion of complications occurs following discharge. Data on the incidence trends of major complications of total hip replacement would facilitate recognition and management of these adverse events. METHODS: We used Medicare claims data on beneficiaries sixty-five years and older who had had elective, primary total hip replacement for a reason other than a fracture (58,521 patients) or had had revision total hip replacement (12,956 patients) between July 1, 1995, and June 30, 1996. We calculated incidence rates of dislocation, pulmonary embolism, and deep hip infection per 10,000 person-weeks for four time-periods following the admission for the surgery (during the index hospitalization, from discharge to four weeks postoperatively, from five to thirteen weeks postoperatively, and from fourteen to twenty-six weeks postoperatively). We then used life-table methods to estimate the cumulative incidence of each complication over the first six postoperative months. RESULTS: Of the patients who had had a primary total hip replacement, 3.9% had a dislocation, 0.9% had a pulmonary embolism, and 0.2% had a deep infection in the first twenty-six postoperative weeks. In the revision total hip replacement cohort, the proportions with dislocation, pulmonary embolism, and deep infection were 14.4%, 0.8%, and 1.1%, respectively. The rates of these adverse outcomes were highest during the index hospitalization, diminished considerably in the period from discharge to four weeks postoperatively, and continued to drop in the periods from five to thirteen and fourteen to twenty-six weeks postoperatively. CONCLUSIONS: The incidence rates of dislocation, pulmonary embolism, and deep infection are highest immediately after total hip replacement, but they continue to be elevated throughout the first three postoperative months. With the lengths of hospital stays continuing to diminish, an increasing proportion of complications will occur in outpatients. These findings provide a basis for developing strategies to prevent these complications in the postdischarge management of patients who have had elective total hip replacement. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See p. 2 for complete description of levels of evidence.

Rates and outcomes of primary and revision total hip replacement in the United States medicare population.

BACKGROUND: Information on the epidemiology of primary total hip replacement is limited, and we are not aware of any reports on the epidemiology of revision total hip replacement. The objective of this study was to characterize the rates and immediate postoperative outcomes of primary and revision total hip replacement in persons sixty-five years of age and older residing in the United States. METHODS: We used Medicare claims submitted by hospitals, physicians, and outpatient facilities between July 1, 1995, and June 30, 1996, to identify individuals who had undergone elective primary total hip replacement for a reason other than a fracture (61,568 patients) or had had revision total hip replacement (13,483 patients). Annual incidence rates of primary and revision total hip replacement were calculated, and multivariate modeling was used to evaluate the association between patient characteristics and surgical rates. The rates of occurrence of five complications within ninety days postoperatively were also evaluated, and relationships between those outcomes and patient characteristics were assessed with use of multivariate models adjusted for hospital and surgeon volume. RESULTS: The rates of primary total hip replacement were three to six times higher than the rates of revision total hip replacement. Women had higher rates than men, and whites had higher rates than blacks. The rates of primary and revision total hip replacement increased with age until the age of seventy-five to seventy-nine years and then declined. The rates of complications occurring within ninety days after primary total hip replacement were 1.0% for mortality, 0.9% for pulmonary embolus, 0.2% for wound infection, 4.6% for hospital readmission, and 3.1% for hip dislocation. The rates after revision total hip replacement were 2.6%, 0.8%, 0.95%, 10.0%, and 8.4%, respectively. Factors associated with an increased risk of an adverse outcome included increased age, gender (men were at higher risk than women), race (blacks were at higher risk than whites), a medical comorbidity, and a low income. CONCLUSIONS: Analysis of United States Medicare population data showed that the rates of total hip replacement increased with age up to the age of seventy-five to seventy-nine years and that blacks had a significantly lower rate of total hip replacement than whites. The overall rates of adverse outcomes were relatively low, but they were significantly higher after revision than after primary total hip replacement. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See p. 2 for complete description of levels of evidence.

Timing of total joint replacement affects clinical outcomes among patients with osteoarthritis of the hip or knee.

OBJECTIVE: To determine the predictors of outcome in patients with osteoarthritis 2 years after receiving total hip or knee replacement. METHODS: A prospective cohort study of 222 osteoarthritis patients undergoing total hip or knee replacement in Boston and Montreal was done. Their postoperative outcomes at 6 months were previously reported. This followup reports on the outcomes after 2 years among the 165 patients (74%) who remained. The subjects were divided into 2 groups according to the median value of their preoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score. The Short Form 36-item physical function subscale and the WOMAC pain and function subscale scores were collected at baseline and at 3, 6, and 24 months postoperatively. Clinical outcomes were analyzed at 2 years, using descriptive and multiple regression analyses. RESULTS: Improvements in pain and function at 2 years were similar to those observed at 6 months. Those subjects with the worst function and pain at the time of surgery (baseline) had comparatively worse function 2 years after surgery. CONCLUSION: In this comparison, the poor outcomes observed at 6 months following total joint replacement in patients with worse baseline functional status persisted after 2 years. Although there are no validated indications for when a patient should optimally have total joint replacement, these data suggest that timing of surgery may be more important than previously realized and, specifically, that performing surgery earlier in the course of functional decline may be associated with better outcome.

Contribution of hospital characteristics to the volume-outcome relationship: dislocation and infection following total hip replacement surgery.

OBJECTIVE: Mortality and complication rates after total hip replacement (THR) are inversely associated with the volume of THRs performed at hospitals and by individual surgeons. It is not clear, however, why a higher volume of such procedures is associated with better outcomes. We evaluated the contribution of hospital structural characteristics to the volume-outcome relationship in THR by examining the rates and predictors of postoperative complications. METHODS: We analyzed data pertaining to 5,211 Medicare patients who underwent primary THR in 1995 or 1996 at 167 hospitals in Colorado, Pennsylvania, and Ohio. Data were derived from several sources, including Medicare Part A and Part B claims, the American Board of Medical Specialties, a hospital survey regarding institution-specific characteristics and structural aspects of the care setting, and the American Hospital Association 1995 Annual Survey. Multivariate models were constructed to determine whether hospital structure or surgeon-associated factors may underlie the relationship between volume of THRs and the occurrence of perioperative orthopedic adverse events, defined as deep wound infection or hip dislocation within 90 days of surgery. RESULTS: Of the patients studied, 2.6% experienced an orthopedic adverse event after THR. Sixty-nine percent fewer events occurred in hospitals where >100 THRs in Medicare patients were performed annually, compared with hospitals where

The development, validation, and testing of a health outcomes burn questionnaire for infants and children 5 years of age and younger: American Burn Association/Shriners Hospitals for Children.

The 12-member American Burn Association/Shriners Hospitals for Children Outcomes Task Force was charged with developing a health outcomes questionnaire for use in children 5 years of age and younger that was clinically based and valid. A 55-item form was tested using a cross-sectional design on the basis of a range of 184 infants and children between 0 and 5 years of age at 8 burn centers, nationally. A total of 131 subjects completed a follow-up health outcomes questionnaire 6 months after the baseline assessment. A comparison group of 285 normal nonburn children was also obtained. Internal consistency reliability of the scales ranged from 0.74 to 0.94. Tests of clinical validity were significant in the hypothesized direction for the majority of scales for length of hospital stay, duration since the burn, percent of body surface area burned, overall clinician assessment of severity of burn injury, and number of comorbidities. The criterion validity of the instrument was supported using the Child Developmental Inventories for Burn Children in early childhood and preschool stages of development comparing normal vs abnormal children. The instrument was sensitive to changes over time following a clinical course observed by physicians in practice. The Health Outcomes Burn Questionnaire for Infants and Children 5 years of age and younger is a clinically based reliable and valid assessment tool that is sensitive to change over time for assessing burn outcomes in this age group.

Disparity in total hip replacement affecting Hispanic Medicare beneficiaries.

OBJECTIVE: To compare the utilization of total hip replacement (THR) between Hispanic persons and non-Hispanic persons in a sample with health insurance. RESEARCH DESIGN: Case-control study using Medicare claims data. PATIENTS: The cases were Medicare beneficiaries from Arizona, Illinois, New Mexico, or Texas who underwent a primary THR. The controls were Medicare beneficiaries who did not receive a THR, matched by age, sex, and county of residence. MEASURES: Beneficiary surnames and the race indicator in Medicare records were used to classify beneficiaries' probability of being Hispanic. Conditional logistic regression was used to estimate the odds of receiving of THR, adjusting for Medicaid eligibility. RESULTS: Six thousand four hundred thirty-seven recipients of a primary THR were matched to 12,874 controls. According to the Medicare race indicator, 1% of recipients of THR and 3.3% of controls were Hispanic (P < or =0.001). The odds of THR decreased as the probability of Hispanic ethnicity increased, from an odds ratio (OR) of 1.00 among beneficiaries with non-Hispanic surnames, to an OR of 0.36 among those with heavily Hispanic surnames (95% CI, 0.31, 0.43). Poverty, as reflected by eligibility for Medicaid, did not modify the low odds of THR among Hispanic persons (OR, 0.25 among Medicaid-eligible Hispanic persons; 95% CI, 0.19, 0.33; and OR, 0.30 among Hispanic persons not Medicaid eligible; 95% CI, 0.24, 0.38). CONCLUSION: Hispanic persons with Medicare receive THR at lower rates than do non-Hispanic persons. Because Medicare covers THR, our findings suggest that under utilization of THR by Hispanic persons cannot be attributed to lack of health insurance alone.