Examining Differences in Recovery Outcomes between Male and Female Hip Fracture Patients: Design and Baseline Results of a Prospective Cohort Study from the Baltimore Hip Studies.

BACKGROUND: Incidence of hip fractures in men is expected to increase, yet little is known about consequences of hip fracture in men compared to women. It is important to investigate differences at time of fracture using the newest technologies and methodology regarding metabolic, physiologic, neuromuscular, functional, and clinical outcomes, with attention to design issues for recruiting frail older adults across numerous settings. OBJECTIVES: To determine whether at least moderately-sized sex differences exist across several key outcomes after a hip fracture. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study (Baltimore Hip Studies 7th cohort [BHS-7]) was designed to include equal numbers of male and female hip fracture patients to assess sex differences across various outcomes post-hip fracture. Participants were recruited from eight hospitals in the Baltimore metropolitan area within 15 days of admission and were assessed at baseline, 2, 6 and 12 months post-admission. MEASUREMENTS: Assessments included questionnaire, functional performance evaluation, cognitive testing, measures of body composition, and phlebotomy. RESULTS: Of 1709 hip fracture patients screened from May 2006 through June 2011, 917 (54%) were eligible and 39% (n=362) provided informed consent. The final analytic sample was 339 (168 men and 171 women). At time of fracture, men were sicker (mean Charlson score= 2.4 vs. 1.6; p<0.001) and had worse cognition (3MS score= 82.3 vs. 86.2; p<0.05), and prior to fracture were less likely to be on bisphosphonates (8% vs. 39%; p<0.001) and less physically active (2426 kilocalories/week vs. 3625; p<0.001). CONCLUSIONS: This paper provides the study design and methodology for recruiting and assessing hip fracture patients and evidence of baseline and pre-injury sex differences which may affect eventual recovery one year later.

An approach to treating a patient with a HeartMate II™ left ventricularassist device in a multiplace hyperbaric chamber: a case report.

INTRODUCTION: Left-ventricular assist devices (LVAD) are becoming a common therapy for end-stage heart failure. These devicesare not tested for pressurization in a hyperbaricchamber by the manufacturer. In this article, we present an approach to modify the power supply in order to safely treat a patient with an LVAD. MATERIALS AND METHODS: Our patient had a HeartMateII™ LVAD and presented for hyperbaric oxygen treatments for severe radiation cystitis. In order to modify this patient's equipment to be compliant with NFPA6 safety standards we made several modifications. In brief, this included eliminating the usage of lithium-ion batteries, modifying the cord to be compatible with Fink chamber outlets, and enclosing the power module in a nitrogen purge. We then used a mock circulatory system to test our modifications and make sure the LVAD continued to have appropriate flow rates. We then conducted training for staff and developed a disaster plan should the LVAD fail at any point. RESULTS: Once we felt comfortable with the modifications and had a plan developed should any problems arise, we then proceeded to treat our patient in the hyperbaric chamber. He successfully underwent 44 hyperbaric treatments for radiation cystitis without complications. CONCLUSION: This case is the second reported patient in the literature with an LVAD that was successfully treated in a multiplace hyperbaric chamber. As LVADs become increasingly popular to manage heart failure, more patients with these devices will present for hyperbaric treatments. With a few modifications, an LVAD patient can be safely and successfully treated in a hyperbaric chamber.

The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA.

Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock (Tsuga canadensis) canopy health affected by an invasive insect, the hemlock woolly adelgid (Adelges tsugae). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study.

Older men who sustain a hip fracture experience greater declines in bone mineral density at the contralateral hip than non-fractured comparators.

Men experience declining bone mineral density (BMD) after hip fracture; however, changes attributable to fracture are unknown. This study evaluated the excess BMD decline attributable to hip fracture among older men. Older men with hip fracture experienced accelerated BMD declines and are at an increased risk of secondary fractures. INTRODUCTION: The objective was to determine whether bone mineral density (BMD) changes in men after hip fracture exceed that expected with aging. METHODS: Two cohorts were used: Baltimore Hip Studies 7th cohort (BHS-7) and Baltimore Men's Osteoporosis Study (MOST). BHS-7 recruited older adults (N = 339) hospitalized for hip fracture; assessments occurred within 22 days of admission and at 2, 6, and 12 months follow-up. MOST enrolled age-eligible men (N = 694) from population-based listings; data were collected at a baseline visit and a second visit that occurred between 10 and 31 months later. The combined sample (n = 452) consisted of Caucasian men from BHS-7 (n = 89) and MOST (n = 363) with ≥ 2 dual-energy X-ray absorptiometry scans and overlapping ranges of age, height, and weight. Mixed-effect models estimated rates of BMD change, and generalized linear models evaluated differences in annual bone loss at the total hip and femoral neck between cohorts. RESULTS: Adjusted changes in total hip and femoral neck BMD were - 4.16% (95% CI, - 4.87 to - 3.46%) and - 4.90% (95% CI, - 5.88 to - 3.92%) in BHS-7 participants; - 1.57% (95% CI, - 2.19 to - 0.96%) and - 0.99% (95% CI, - 1.88 to - 0.10%) in MOST participants; and statistically significant (P < 0.001) between-group differences in change were - 2.59% (95% CI, - 3.26 to - 1.91%) and - 3.91% (95% CI, - 4.83 to - 2.98%), respectively. CONCLUSION: Hip fracture in older men is associated with accelerated BMD declines at the non-fractured hip that are greater than those expected during aging, and pharmacological interventions in this population to prevent secondary fractures may be warranted.

Improving community ambulation after hip fracture: protocol for a randomised, controlled trial.

INTRODUCTION: After a hip fracture in older persons, significant disability often remains; dependency in functional activities commonly persists beyond 3 months after surgery. Endurance, dynamic balance, quadriceps strength, and function are compromised, and contribute to an inability to walk independently in the community. In the United States, people aged 65 years and older are eligible to receive Medicare funding for physiotherapy for a limited time after a hip fracture. A goal of outpatient physiotherapy is independent and safe household ambulation 2 to 3 months after surgery. Current Medicare-reimbursed post-hip-fracture rehabilitation fails to return many patients to pre-fracture levels of function. Interventions delivered in the home after usual hip fracture physiotherapy has ended could promote higher levels of functional independence in these frail and older adult patients. PRIMARY OBJECTIVE: To evaluate the effect of a specific multi-component physiotherapy intervention (PUSH), compared with a non-specific multi-component control physiotherapy intervention (PULSE), on the ability to ambulate independently in the community 16 weeks after randomisation. DESIGN: Parallel, two-group randomised multicentre trial of 210 older adults with a hip fracture assessed at baseline and 16 weeks after randomisation, and at 40 weeks after randomisation for a subset of approximately 150 participants. PARTICIPANTS AND SETTING: A total of 210 hip fracture patients are being enrolled at three clinical sites and randomised up to 26 weeks after admission. Study inclusion criteria are: closed, non-pathologic, minimal trauma hip fracture with surgical fixation; aged ≥ 60 years at the time of randomisation; community residing at the time of fracture and randomisation; ambulating without human assistance 2 months prior to fracture; and being unable to walk at least 300 m in 6minutes at baseline. Participants are ineligible if the interventions are deemed to be unsafe or unfeasible, or if the participant has low potential to benefit from the interventions. INTERVENTIONS: Participants are randomly assigned to one of two multi-component treatment groups: PUSH or PULSE. PUSH is based on aerobic conditioning, specificity of training, and muscle overload, while PULSE includes transcutaneous electrical nerve stimulation, flexibility activities, and active range of motion exercises. Participants in both groups receive 32 visits in their place of residence from a study physiotherapist (two visits per week on non-consecutive days for 16 weeks). The physiotherapists' adherence to the treatment protocol, and the participants' receipt of the prescribed activities are assessed. Participants also receive counselling from a registered dietician and vitamin D, calcium and multivitamin supplements during the 16-week intervention period. MEASUREMENTS: The primary outcome (community ambulation) is the ability to walk 300 m or more in 6minutes, as assessed by the 6-minute walk test, at 16 weeks after randomisation. Other measures at 16 and 40 weeks include cost-effectiveness, endurance, dynamic balance, walking speed, quadriceps strength, lower extremity function, activities of daily living, balance confidence, quality of life, physical activity, depressive symptoms, increase of ≥ 50 m in distance walked in 6minutes, cognitive status, and nutritional status. ANALYSIS: Analyses for all aims will be performed according to the intention-to-treat paradigm. Except for testing of the primary hypothesis, all statistical tests will be two-sided and not adjusted for multiple comparisons. The test of the primary hypothesis (comparing groups on the proportion who are community ambulators at 16 weeks after randomisation) will be based on a one-sided 0.025-level hypothesis test using a procedure consisting of four interim analyses and one final analysis with critical values chosen by a Hwang-Shih-Decani alpha-spending function. Analyses will be performed to test group differences on other outcome measures and to examine the differential impact of PUSH relative to PULSE in subgroups defined by pre-selected participant characteristics. Generalised estimating equations will be used to explore possible delayed or sustained effects in a subset of participants by comparing the difference between PUSH and PULSE in the proportion of community ambulators at 16 weeks with the difference at 40 weeks. DISCUSSION: This multicentre randomised study will be the first to test whether a home-based multi-component physiotherapy intervention targeting specific precursors of community ambulation (PUSH) is more likely to lead to community ambulation than a home-based non-specific multi-component physiotherapy intervention (PULSE) in older adults after hip fracture. The study will also estimate the potential economic value of the interventions.

Changes in bone mineral density over time by body mass index in the health ABC study.

UNLABELLED: Obesity appears protective against osteoporosis in cross-sectional studies. However, results from this longitudinal study found that obesity was associated with bone loss over time. Findings underscore the importance of looking at the longitudinal relationship, particularly given the increasing prevalence and duration of obesity among older adults. INTRODUCTION: Cross-sectional studies have found a positive association between body mass index (BMI) and bone mineral density (BMD), but little is known about the longitudinal relationship in US older adults. METHODS: We examined average annual rate of change in BMD by baseline BMI in the Health, Aging, and Body Composition Study. Repeated measurement of BMD was performed with dual-energy X-ray absorptiometry (DXA) at baseline and years 3, 5, 6, 8, and 10. Multivariate generalized estimating equations were used to predict mean BMD (femoral neck, total hip, and whole body) by baseline BMI (excluding underweight), adjusting for covariates. RESULTS: In the sample (n = 2570), 43 % were overweight and 24 % were obese with a mean baseline femoral neck BMD of 0.743 g/cm(2), hip BMD of 0.888 g/cm(2), and whole-body BMD of 1.09 g/cm(2). Change in total hip or whole-body BMD over time did not vary by BMI groups. However, obese older adults lost 0.003 g/cm(2) of femoral neck BMD per year more compared with normal weight older adults (p < 0.001). Femoral neck BMD change over time did not differ between the overweight and normal weight BMI groups (p = 0.74). In year 10, adjusted femoral neck BMD ranged from 0.696 g/cm(2) among obese, 0.709 g/cm(2) among normal weight, and 0.719 g/cm(2) among overweight older adults. CONCLUSIONS: Findings underscore the importance of looking at the longitudinal relationship between body composition and bone mineral density among older adults, indicating that high body mass may not be protective for bone loss over time.

The association between body mass index, weight loss and physical function in the year following a hip fracture.

OBJECTIVES: To determine whether body mass index (BMI) at the time of hospitalization or weight change in the period immediately following hospitalization predict physical function in the year after hip fracture. DESIGN: Prospective observational study. SETTING: Two hospitals in Baltimore, Maryland. PARTICIPANTS: Female hip fracture patients age 65 years or older (N=136 for BMI analysis, N=41 for analysis of weight change). MEASUREMENTS: Body mass index was calculated based on weight and height from the medical chart. Weight change was based on DXA scans at 3 and 10 days post fracture. Physical function was assessed at 2, 6 and 12 months following fracture using the lower extremity gain scale (LEGS), walking speed and grip strength. RESULTS: LEGS score and walking speed did not differ across BMI tertiles. However, grip strength differed significantly across BMI tertiles (p=0.029), with underweight women having lower grip strength than normal weight women at all time points. Women experiencing the most weight loss (>4.8%) had significantly lower LEGS scores at all time points, slower walking speed at 6 months, and weaker grip strength at 12 months post-fracture relative to women with more modest weight loss. In adjusted models, overall differences in function and functional change across all time points were not significant. However, at 12 months post fracture,women with the most weight loss had an average grip strength 7.0 kg lower than women with modest weight loss (p=0.030). CONCLUSIONS: Adjustment for confounders accounts for much of the relationships between BMI and function and weight change and function in the year after fracture. However, weight loss is associated with weakness during hip fracture recovery. Weight loss during and immediately after hospitalization appears to identify women at risk of poor function and may represent an important target for future interventions.

The hormonal profile of hip fracture female patients differs from community-dwelling peers over a 1-year follow-up period.

UNLABELLED: Hormone levels were compared over a 1-year period between elderly women who had sustained a hip fracture and women of similar age and functional ability. Our study suggests progressive hormonal changes that may contribute to severe bone loss during the year following hip fracture. INTRODUCTION: Alterations in hormones affecting the musculoskeletal system may increase risk of hip fracture or poor post-fracture recovery in postmenopausal women. Most studies lack appropriate reference groups, and thus cannot assess the extent to which these alterations are attributable to hip fracture. METHODS: Women aged ≥65 years hospitalized for an acute hip fracture (Baltimore Hip Studies, BHS-3; n = 162) were age-matched to 324 women enrolled in the Women's Health and Aging Study I, a Baltimore-based cohort with similar functional status to the pre-fracture status of BHS-3 women. Both studies enrolled participants from 1992 to 1995. Insulin-like growth hormone-1 (IGF-1), parathyroid hormone (PTH), 1,25 dihydroxyvitamin D [1,25(OH)2D], and osteocalcin were evaluated at baseline and 2, 6, and 12 months post-fracture, and at baseline and 12 months in the comparison group. Between-group differences in trajectories of each hormone were examined. RESULTS: Baseline mean IGF-1 levels were significantly lower in hip fracture patients than the comparison group (75.0 vs. 110.5 µg/dL; p < 0.001). Levels increased by 2 months post-fracture, but remained significantly lower than those in the comparison group throughout the 12-month follow-up (p < 0.01). Levels of PTH and osteocalcin were similar between groups at baseline, but rose during the year post-fracture to significantly differ from the comparison women (p < 0.001). 1,25(OH)2D levels did not differ between the hip fracture and comparison women at any time. CONCLUSIONS: Older women who have sustained a hip fracture have progressive changes in hormonal milieu that exceed those of women of similar health status during the year following fracture.

Women with hip fracture experience greater loss of geometric strength in the contralateral hip during the year following fracture than age-matched controls.

UNLABELLED: This study examined femur geometry underlying previously observed decline in BMD of the contralateral hip in older women the year following hip fracture compared to non-fractured controls. Compared to controls, these women experienced a greater decline in indices of bone structural strength, potentially increasing the risk of a second fracture. INTRODUCTION: This study examined the femur geometry underlying previously observed decline in BMD of the contralateral hip in the year following hip fracture compared to non-fractured controls. METHODS: Geometry was derived from dual-energy X-ray absorptiometry scan images using hip structural analysis from women in the third cohort of the Baltimore Hip Studies and from women in the Study of Osteoporotic Fractures. Change in BMD, section modulus (SM), cross-sectional area (CSA), outer diameter, and buckling ratio (BR) at the narrow neck (NN), intertrochanteric (IT), and shaft (S) regions of the hip were compared. RESULTS: Wider bones and reduced CSA underlie the significantly lower BMD observed in women who fractured their hip resulting in more fragile bones expressed by a lower SM and higher BR. Compared to controls, these women experienced a significantly greater decline in CSA (-2.3% vs. -0.2%NN, -3.2% vs. -0.5%IT), SM (-2.1% vs. -0.2%NN, -3.9% vs. -0.6%IT), and BMD (-3.0% vs. -0.8%NN, -3.3% vs. -0.6%IT, -2.3% vs. -0.2%S) and a greater increase in BR (5.0% vs. 2.1%NN, 6.0% vs. 1.3%IT, 4.4% vs. 1.0%S) and shaft outer diameter (0.9% vs. 0.1%). CONCLUSION: The contralateral femur continued to weaken during the year following fracture, potentially increasing the risk of a second fracture.

Women with hip fracture have a greater rate of decline in bone mineral density than expected: another significant consequence of a common geriatric problem.

INTRODUCTION: Hip fracture is a major public health problem, annually affecting over 350,000 persons in the United States and 1.6 million worldwide. Consequences include decreased survival, loss of independence, and increased risk of subsequent fractures. A substantial decline in bone mineral density (BMD) also occurs, yet the magnitude of the decline specifically attributable to hip fracture has not been documented. METHODS: To determine the amount of BMD decline attributable to hip fracture, the rate of decline in BMD in a cohort of hip fracture patients was compared with that in a cohort of women of similar age and BMD but without hip fracture. All subjects were community dwelling when enrolled. Hip fracture patients in the Baltimore Hip Studies (BHS) came from two hospitals in Baltimore, Maryland, from 1992 through 1995; comparison subjects came from the Study of Osteoporotic Fracture (SOF) enrolled in four areas of the United States during the same period. Eighty-four white, female hip fracture patients 65 years and older from the BHS were compared with 168 SOF participants matched on age, race, and BMD at baseline. BMD of the femoral neck and total hip was measured by dual-energy x-ray absorptiometry. RESULTS: Hip fracture patients had a greater decline in BMD during the 12-month postfracture follow-up than that expected on the basis of the nonfracture cohort: 4.9% vs. 0.4% at the femoral neck and 3.5% vs. 0.7% for the total hip. The decline in BMD in hip fracture patients was 11.8 times the amount expected at the femoral neck (matched on age and baseline BMD and adjusted for between-cohort differences in smoking prevalence) and 4.9 times that expected for the total hip at the end of 1 year after the hip fracture. CONCLUSION: In this sample of older women, bone loss over the year following hip fracture far exceeded that expected and is an important clinical management concern.

A clinically meaningful difference was generated for a performance measure of recovery from hip fracture.

BACKGROUND AND OBJECTIVE: The Lower Extremity Gain Scale (LEGS) is a performance measure of tasks that are often impaired in hip fracture patients. This study was designed to determine a clinically meaningful difference in LEGS. METHODS: The population was 139 female patients (age >65 years) admitted to Baltimore hospitals. Recovery levels were estimated by fitting trajectory curves for the cohort for the 12 months post fracture. The clinically meaningful difference was evaluated using an anchor-based approach, examining the relationship between the LEGS recovery level and age. A second, distribution-based method used an effect size of .20. RESULTS: According to our model, a difference of 5 years in age corresponded to a difference of 1.6-3.6 points in LEGS scores. The standard deviation for LEGS at 12 months was 8.0; thus, Cohen's effect size of 0.2 would equate to a difference of 1.6 points. CONCLUSION: This suggests that a clinically meaningful difference in the LEGS scores for a population in this age range would be 2-3 points.

Model testing for reliability and validity of the Outcome Expectations for Exercise Scale.

BACKGROUND: Development of a reliable and valid measure of outcome expectations for exercise appropriate for older adults will help establish the relationship between outcome expectations and exercise. Once established, this measure can be used to facilitate the development of interventions to strengthen outcome expectations and improve adherence to regular exercise in older adults. OBJECTIVES: Building on initial psychometrics of the Outcome Expectation for Exercise (OEE) Scale, the purpose of the current study was to use structural equation modeling to provide additional support for the reliability and validity of this measure. METHODS: The OEE scale is a 9-item measure specifically focusing on the perceived consequences of exercise for older adults. The OEE scale was given to 191 residents in a continuing care retirement community. The mean age of the participants was 85 +/- 6.1 and the majority were female (76%), White (99%), and unmarried (76%). Using structural equation modeling, reliability was based on R2 values, and validity was based on a confirmatory factor analysis and path coefficients. RESULTS: There was continued evidence for reliability of the OEE based on R2 values ranging from .42 to .77, and validity with path coefficients ranging from .69 to .87, and evidence of model fit (X2 of 69, df = 27, p < .05, NFI = .98, RMSEA = .07). CONCLUSION: The evidence of reliability and validity of this measure has important implications for clinical work and research. The OEE scale can be used to identify older adults who have low outcome expectations for exercise, and interventions can then be implemented to strengthen these expectations and thereby improve exercise behavior.

Measurement of activity in older adults: reliability and validity of the Step Activity Monitor.

The purpose of this study was to test the reliability and validity of the Step Activity Monitor (SAM) when used with older adults. A total of 30 subjects with a mean age of 86 +/- 6.1 participated in the study. Sixty one-minute walks were measured with the SAM, and two observers visually counted steps. Four participants wore the SAM for 6 to 48 hours and maintained activity diaries. The intraclass correlation for the SAM recordings was R = .84. There was an overall step counting accuracy of 96%. The diaries supported the SAM data for those who wore the SAM for extended periods. The SAM is an easy to use, comfortable, valid, and reliable measure of activity in older adults and particularly may be useful to triangulate measurement of activity in these individuals.

Outcome expectations for exercise scale: utility and psychometrics.

OBJECTIVES: The purpose of this study was to develop a measure of outcome expectations for exercise specifically for the older adult (The Outcome Expectations for Exercise [OEE] Scale), and to test the reliability and validity of this measure in a sample of older individuals. This scale was developed based on Bandura's theory of self-efficacy and the work of prior researchers in the development of measures of outcome expectations. METHODS: The OEE scale, which was completed during a face-to-face interview, was tested in a sample of 175 residents in a continuing care retirement community. RESULTS: There was support for the internal consistency of the OEE scale (alpha coefficient of .89), and some support for reliability based on a structural equation modeling approach that used R2 estimates, although less than half of these were greater than 0.5. There was evidence of validity of the measure based on: (a) a confirmatory factor analysis in which the model fit the data (normed fit index [NFI] = .99, root mean square error of approximation [RMSEA] - .07, chi2/df = 2.8); (b) support for the hypothesis that those who exercised regularly had higher OEE scores than those who did not (F = 31.3, p < .05, eta squared = .15); and (c) a statistically significant relationship between outcome expectations and self-efficacy expectations (r = .66). DISCUSSION: This study provides some initial support for the reliability and validity of the OEE scale. Outcome expectations for exercise were related to exercise behavior in the older adult, and the OEE scale can help identify older adults with low outcome expectations for exercise. Interventions can then be implemented to help these individuals strengthen their outcome expectations, which may subsequently improve exercise behavior.

Postdischarge medication use of elderly cardiac patients from urban and rural locations.

BACKGROUND: After discharge from an acute care setting, elderly cardiac patients take a variety of medications in the home setting. Their pharmacologic regimens are often quite complex, and may involve drugs from several therapeutic categories. Patterns of medication use can be one measure of patient status after discharge because they can indicate whether medical conditions are stabilized. A problem related to medications during the postdischarge period is residence of the patient. For persons discharged to rural settings, access to health care resources and follow-up monitoring of medications may be problematic. METHODS: This longitudinal study followed postdischarge medication use over a 5-month period. Thirty-two elderly persons admitted to a large tertiary care center for treatment of cardiac conditions were recruited. Baseline information was collected on demographics and health status, and subjects were then interviewed by telephone at 2, 4, 12, and 20 weeks postdischarge. Analysis of functional health complaints assessed by the Medical Outcomes Short Form (SF-36) and cardiac symptom scores were correlated with new and standing prescriptions over time and across geographic locations. Potential confounders such as age, gender, and severity of illness were controlled for. RESULTS: Statistical analyses on continuity of medication use and changes in the category of medication prescribed revealed that urban subjects were prescribed more drugs and experienced significantly more alterations in their drug regimens. CONCLUSIONS: Contrary to expectations, urban subjects appeared to do worse over the postdischarge period with greater drug utilization that directly predicted the number of hospital readmissions and number of emergency room visits, even though their severity of illness was no different from their rural counterparts at the time of discharge.

Structure, radial growth dynamics and recent climatic variations of a 320-year-old Pinus rigida rock outcrop community.

The composition, structure and dendroecology of a 320-year-old Pinus rigida rock outcrop community was studied in the Shawangunk Mountains of southeastern New York. This represents one of the oldest known examples of this forest type and it is located on one of the most extreme sites in the northeastern United States. P. rigida represented 88% of all sampled trees, which typically grew on individual soil islands with soil depths of 8-35 cm surrounded by exposed bedrock. The forest was uneven-aged and P. rigida exhibited continuous recruitment into the tree size classes since the late 1600s, suggesting that it represents a physiographic climax for this species. However, a limited amount of Nyssa sylvatica and Quercus prinus recruitment started after 1830. Peak recruitment of P. rigida trees in 1720-1760 and 1860-1890 coincided with parabolic-shaped releases in their radial growth, possibly in response to disturbances. Tree ring growth was typically <0.4 mm/year since the 1850s and <0.3 mm/year during a prolonged and severe drought in the 1960s. However, large increases in precipitation and temperature from 1970 to 1993 were correlated with a dramatic post-drought growth response producing the highest ring width index values throughout the life of 260 to 280-year-old trees. Thus, we attribute certain moderate growth releases (>50%) lasting 10-15 years to climate, rather than disturbance. Tree growth and recruitment at the study site were influenced by a complex interaction of climate, soil and disturbance factors. Coupling of species recruitment, tree ring and climatic data in this study provided an improved technique for understanding forest growth and dynamics.

Localized clotted blood as evidence of visceral trauma on CT: the sentinel clot sign.

We retrospectively reviewed the CT scans of 116 patients with abdominal trauma who had visceral injuries to determine if identification on CT of focal high-density clotted blood (a "sentinel clot") was an accurate sign of injury to an adjacent organ. The sentinel clot sign was sensitive, present in 101 (84%) of 120 visceral injuries with only three false-positive cases. Whereas CT visualized the visceral injury itself in 86% of cases, the sentinel clot was the only clue as to the source of hemorrhage in 14% of the cases. Splenic and bowel/mesenteric injuries were frequently subtle, and the focal clot helped to focus attention on the traumatic lesion. In 9% of splenic trauma cases and 32% of bowel/mesenteric injuries, the sentinel clot was the only positive finding. Localized clot is a frequent and accurate sign of injury to an adjacent organ. By facilitating diagnosis of trauma to a specific organ, it may influence the management decision of surgical vs conservative therapy.

Staging of internal derangements of the TMJ with magnetic resonance imaging: preliminary observations.

Although MRI has been reported to be accurate in diagnosing displaced TMJ menisci, it has not been used to characterize the condition of the meniscus. A staging system of internal derangement of the TMJ using MRI signal characteristics and morphology of the meniscus is presented. A normal meniscus has the appearance of a small "drumstick" and is positioned superiorly on the mandibular condyle. It produces a small amount of intermediate signal on the MRI. A grade 1 displaced meniscus has normal shape and signal; a grade 2 meniscus has normal shape and absent signal; a grade 3 meniscus has abnormal shape and absent signal. There was a significant correlation between meniscus grade and chronicity of symptoms, severity of pain, and presence of degenerative joint disease in 62 joints (39 patients).

Optimal mouth position for magnetic resonance imaging of the temporomandibular joint disk.

Optimal mouth positioning for magnetic resonance imaging of the TMJ is controversial. This study evaluates the closed mouth position and partial-open mouth position for diagnostic accuracy of anterior displacement of the disk. Sixty-two joints were considered abnormal in at least one position. In the positive joints, the closed mouth position sequences were all abnormal and diagnostic, while 34% of partial-open mouth position sequences were falsely normal. It was found that the closed mouth position provides higher diagnostic accuracy for disk displacement, although optimal examinations include imaging in both positions.

CT of false-negative peritoneal lavage following blunt abdominal trauma.

The CT findings are presented in a patient with blunt trauma and a false-negative peritoneal lavage due to extraperitoneal insertion of the lavage catheter. Computed tomography correctly identified the presence of hemoperitoneum and the site of injury involving the small bowel mesentery. The diagnostic accuracy in peritoneal lavage and its relationship to abdominal CT is reviewed.