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Biomedical subjects

James C Torner

Publications and source records attributed to James C Torner.

At least 19 recordsLinked to original sources

Effects of intraoperative hypothermia on neuropsychological outcomes after intracranial aneurysm surgery.

OBJECTIVE: Subarachnoid hemorrhage and surgical obliteration of ruptured intracranial aneurysms are frequently associated with neurological and neuropsychological abnormalities. We reported that intraoperative cooling did not improve neurological outcome in good-grade surgical subarachnoid hemorrhage patients, as assessed by the Glasgow Outcome Scale score or other neurological and functional measures (National Institutes of Health Stroke Scale, Rankin Disability Scale, Barthel Activities of Daily Living). We now report the results of neuropsychological testing in these patients. METHODS: A total of 1,001 patients who bled < or = 14 days before surgery were randomly assigned to intraoperative hypothermia (t = 33 degrees C) or normothermia (37 degrees C). Outcome was assessed approximately 3 months after surgery. Patients underwent the Benton Visual Retention, Controlled Oral Word Association, Rey-Osterrieth Complex Figure, Grooved Pegboard, and the Trail Making tests. T-scores for each test were calculated from normative data. T-scores were averaged to calculate a Composite Score. A test result (or the Composite Score) was considered "impaired" if the T-score was two or more standard deviations below the norm. A Mini-Mental State Examination was also performed. RESULTS: Neurological outcome data were available in 1,000 patients. Sixty-one patients died. Of the 939 survivors, 873 completed 3 or more tests (exclusive of the Mini-Mental State Examination). Patients with poor neurological outcomes were less likely to complete testing; only 3.9% of Good Outcome (Glasgow Outcome Scale score = 1) patients were untested, compared with 38.6% of patients with Glasgow Outcome Scale scores of 3 and 4. There were no prerandomization demographic differences between the two treatment groups. For hypothermic patients, 16.8% were impaired from their Composite Score versus 20.0% of patients in the normothermic group (p = 0.317). For patients in the hypothermic group, 54.5% were impaired on at least one test, compared with 55.5% of patients in the normothermic group (p = 0.865). Similar results were seen in patients with baseline WFNS scores = I. Mini-Mental State Examination scores in the hypothermic and normothermic groups were 27.4 +/- 3.8 and 26.8 +/- 4.5, respectively. INTERPRETATION: This is the largest prospective evaluation of neuropsychological function after subarachnoid hemorrhage to date. Testing was completed in a high fraction of patients, demonstrating the feasibility of such testing in a large trial. However, the frequent inability to complete testing in poor-outcome patients suggests that testing may be best used to refine outcome assessments in good-grade patients. Many patients showed impairment on at least one test, with global impairment present in 17 to 20% of patients (18-21% of survivors). This was true even among the patients with the best preoperative condition (WFNS = 1). There was no difference in the incidence of impairment between hypothermic and normothermic groups.

Aged↗

Physical activity augments bone mineral accrual in young children: The Iowa Bone Development study.

OBJECTIVES: This 3-year follow-up study examined associations between physical activity and bone mineral content (BMC) and whether physical activity augments BMC accrual. STUDY DESIGN: Participants were 370 children (mean age baseline 5.3 years, follow-up 8.6 years). Physical activity was measured using 4-day accelerometry. BMC was measured using dual energy x-ray absorptiometry. RESULTS: After adjustment for baseline BMC, age, and body size, mean physical activity predicted follow-up BMC at the hip, trochanter, spine, and whole body in boys and at the trochanter and whole body in girls. The variability in BMC explained by physical activity was modest (1% to 2%). However, based on a general linear model with adjustment for baseline BMC and body size, children who maintained high levels of physical activity accrued, on average, 14% more trochanteric BMC and 5% more whole-body BMC relative to peers maintaining low levels of physical activity. CONCLUSIONS: This study suggests that maintaining high levels of everyday physical activity contributes to increases in BMC in young children, particularly at the trochanter.

Bone Density↗

Nonadherence to depression treatment guidelines among veterans with diabetes mellitus.

OBJECTIVE: To assess the adequacy of antidepressant dosage and duration among veterans with and without diabetes mellitus (DM), as well as provider-level and patient-level predictors of depression care quality, based on Veterans Health Administration (VHA) evidence-based clinical practice guidelines. STUDY DESIGN: Retrospective (1997-2005) cohort study of administrative, clinical, and pharmacy data from a midwestern VHA facility. METHODS: The sample included 2332 subjects (773 with DM) who had a new episode of depression, received antidepressant therapy, and had neither schizophrenia nor bipolar disorder. Antidepressant dosage and duration were evaluated in the acute and continuation phases. Dosage was adequate if the treatment dosage met the minimum therapeutic dosage specified in VHA guidelines. Treatment duration was adequate if the medication possession ratio was at least 80%. Multivariate logistic regression analysis was used to calculate odds ratios (ORs), adjusted for demographic, clinical, and healthcare utilization characteristics. RESULTS: Most subjects received an adequate dosage during the acute (88%) and continuation (58%) phases. Subjects with DM were 1.51-fold more likely to receive adequate dosage during the acute phase but were similarly likely (OR, 1.15) to receive adequate dosage during the continuation phase. Few subjects (<10%) received adequate treatment duration. Diabetes mellitus was not associated with less adequate duration during the acute phase (OR, 1.14). Few factors were identified as significant predictors of both antidepressant dosage and duration. CONCLUSIONS: Diabetes mellitus did not adversely affect depression care quality. Adequate antidepressant dosages were prescribed, but treatment duration fell short of guideline recommendations. Strategies to more effectively manage depression treatment are needed.

Adult↗

Mild intraoperative hypothermia during surgery for intracranial aneurysm.

BACKGROUND: Surgery for intracranial aneurysm often results in postoperative neurologic deficits. We conducted a randomized trial at 30 centers to determine whether intraoperative cooling during open craniotomy would improve the outcome among patients with acute aneurysmal subarachnoid hemorrhage. METHODS: A total of 1001 patients with a preoperative World Federation of Neurological Surgeons score of I, II, or III ("good-grade patients"), who had had a subarachnoid hemorrhage no more than 14 days before planned surgical aneurysm clipping, were randomly assigned to intraoperative hypothermia (target temperature, 33 degrees C, with the use of surface cooling techniques) or normothermia (target temperature, 36.5 degrees C). Patients were followed closely postoperatively and examined approximately 90 days after surgery, at which time a Glasgow Outcome Score was assigned. RESULTS: There were no significant differences between the group assigned to intraoperative hypothermia and the group assigned to normothermia in the duration of stay in the intensive care unit, the total length of hospitalization, the rates of death at follow-up (6 percent in both groups), or the destination at discharge (home or another hospital, among surviving patients). At the final follow-up, 329 of 499 patients in the hypothermia group had a Glasgow Outcome Score of 1 (good outcome), as compared with 314 of 501 patients in the normothermia group (66 percent vs. 63 percent; odds ratio, 1.14; 95 percent confidence interval, 0.88 to 1.48; P=0.32). Postoperative bacteremia was more common in the hypothermia group than in the normothermia group (5 percent vs. 3 percent, P=0.05). CONCLUSIONS: Intraoperative hypothermia did not improve the neurologic outcome after craniotomy among good-grade patients with aneurysmal subarachnoid hemorrhage.

Bacteremia↗

Vulvar disease: a pelvic floor pain disorder?

OBJECTIVE: The purpose of this study was to compare the rates of painful bladder syndrome and functional bowel disorders in women with vulvar disease and control subjects. STUDY DESIGN: In this cross-sectional survey, a questionnaire that contained validated outcome measures was administered to women who were seeking care in a vulvar disease clinic and in general gynecology clinics. RESULTS: Women who were seen at a vulvar disease clinic were 2.18 (95% CI, 1.19, 3.97) times more likely to have painful bladder syndrome and 2.13 (95% CI, 1.35, 3.35) times more likely to have functional bowel disorders than general gynecology clinic control subjects after multivariable analyses. CONCLUSION: Painful bladder syndrome and functional bowel disorders are more prevalent in women who are seen at a vulvar disease clinic than gynecology clinics control subjects. These associations may reflect a common origin for these disorders in certain women. These findings lay the groundwork for future research to investigate a potential "pelvic floor pain disorder," which is a disease entity that would combine the diagnostic criteria for vulvar, bladder, and bowel pain disorders.

Adult↗

Complications after therapeutic trauma laparotomy.

BACKGROUND: Therapeutic trauma laparotomy (TTL) is a common emergency procedure after traumatic abdominal injury, but it can lead to complications and even death. We explored the role of the time from emergency department (ED) arrival to surgical intervention as a predictor of complications and mortality from TTL. STUDY DESIGN: This is a retrospective study of 175 patients receiving TTL between July 1997 and October 2003 in a Level I teaching hospital serving a primarily rural population. Mortality after TTL and complications, both general and abdominal, were the main outcomes. Time from ED arrival to operation was the primary exposure. Confounders, including time from injury to ED arrival, age, gender, injury severity, and patient status, were controlled in logistic models. RESULTS: Of the 175 TTL patients, 23 (13.1%) died, 102 (58.3%) had abdominal complications, and 119 (68.0%) had general complications. Controlling for confounders, patients whose operation began more than 1 hour after ED arrival were 11.3 (95% CI=2.2 to 58.8) times more likely to die and 3.1 (95% CI=1.44 to 6.60) times more likely to have complications. CONCLUSIONS: The traumatologist has little control over patient treatment and transfer before ED arrival. After arrival the traumatologist can reduce negative outcomes by reducing the time for patient assessment and start of TTL, when warranted.

Abdominal Injuries↗

Hospital volume-outcome relationships among medical admissions to ICUs.

BACKGROUND: Positive relationships between hospital volume and outcomes have been demonstrated for several surgeries and medical conditions. However, little is known about the volume-outcome relationship in patients admitted to medical ICUs. OBJECTIVE: To determine the relationship between hospital volume and risk-adjusted in-hospital mortality for patients admitted to ICUs with respiratory, neurologic, and GI disorders. DESIGN: Retrospective cohort study. SETTING: Twenty-nine hospitals in a single metropolitan area. PATIENTS: Adult ICU admissions from 1991 through 1997. METHODS: Using Cox proportional hazards models, we compared in-hospital mortality between tertiles of hospital volume (high, medium, and low) for respiratory (n = 16,949), neurologic (n = 13,805), and GI (n = 12,881) diseases after adjusting for age, gender, admission severity of illness, admitting diagnosis, and source. Severity of illness was measured using the APACHE (acute physiology and chronic health evaluation) III methodology. RESULTS: Among respiratory and neurologic ICU admissions, hazard ratios were similar (p > or = 0.05) in patients in low-, medium-, and high-volume hospitals. However, among GI diagnoses, risk of mortality was lower in high-volume hospitals, relative to low-volume hospitals (hazard ratio, 0.68; 95% confidence interval [CI], 0.54 to 0.85; p < 0.001), and was somewhat lower in medium-volume hospitals (hazard ratio, 0.83; 95% CI, 0.68 to 1.01; p = 0.06). Among subgroups based on severity of illness, high-volume hospitals had lower mortality, relative to low-volume hospitals, among sicker patients (APACHE III score > 57) in the respiratory cohort (hazard ratio, 0.77; 95% CI, 0.59 to 0.99) and the GI cohort (hazard ratio, 0.67; 95% CI, 0.53 to 0.85). CONCLUSIONS: Associations between ICU volume and risk-adjusted mortality were significant for patients with GI diagnoses and for sicker patients with respiratory diagnoses. However, associations were not significant for patients with neurologic diagnoses. The lack of a consistent volume-outcome relationship may reflect unmeasured patient complexity in higher-volume hospitals, relative standardization of care across ICUs, or lack of efficacy of some accepted ICU processes of care.

APACHE↗

Percentile distributions of bone measurements in Iowa children: the Iowa Bone Development Study.

Four hundred twenty-eight white children (200 boys and 228 girls) ages 4.5-6.5 yr had spine, hip, and whole-body bone mineral density (BMD) and bone mineral content (BMC) measured by dual-energy X-ray absorptiometry(DXA) as part of the Iowa Bone Development Study. Anthropometric measurements, including height, weight, and body mass index (BMI) were determined for each child at the time the bone measurements were made. The age- and gender-specific height percentile based on the 2000 CDC Growth Charts (www.cdc.gov/growthcharts/) was determined for each child. These percentiles were used to classify children into four groups as defined by the 25th, 50th,and 75th percentile cutpoints. Percentile distributions were determined within each height quartile group to delineate percentiles (5th, 25th, 50th, 75th, 95th) for BMD and BMC. Gender differences in BMD and BMC were investigated before and after stratification into height groups. Boys had higher age-height-weight-adjusted means for most BMD and BMC measures except spine BMD. Bone measurements increased with height quartile, indicating that taller children have greater BMD and BMC compared to shorter children of the same age and gender. Within any given quartile,mean BMD and BMC measurements were similar for boys and girls, with the exception of hip BMD, for which values were consistently higher for boys (p < 0.05). In addition, whole-body BMC values were higher for boys in quartiles 1 and 3 (p < 0.05). These bone measures provide norms for young white children and serve as a reference for comparison with other racial and ethnic groups, as well as with childhood populations that are at risk for osteopenia because of chronic disease. Gender, age, and height are useful clinical predictors of BMD and BMC in young children.

Bone Density↗

Randomized trial of effect of alendronate continuation versus discontinuation in women with low BMD: results from the Fracture Intervention Trial long-term extension.

UNLABELLED: To determine the effects of continuation versus discontinuation of alendronate on BMD and markers of bone turnover, we conducted an extension trial in which 1099 older women who received alendronate in the FIT were re-randomized to alendronate or placebo. Compared with women who stopped alendronate, those continuing alendronate for 3 years maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued treatment. However, among women who discontinued alendronate and took placebo in the extension, BMD remained higher, and reduction in bone turnover was greater than values at FIT baseline, showing persistence of alendronate's effects on bone. INTRODUCTION: Prior trials including the Fracture Intervention Trial (FIT) have found that therapy with alendronate increases BMD and decreases fracture risk for up to 4 years in postmenopausal women with low BMD. However, it is uncertain whether further therapy with alendronate results in preservation or further gains in BMD and if skeletal effects of alendronate continue after treatment is stopped. MATERIALS AND METHODS: We conducted a follow-up placebo-controlled extension trial to FIT (FIT long-term extension [FLEX]) in which 1099 women 60-86 years of age who were assigned to alendronate in FIT with an average duration of use of 5 years were re-randomized for an additional 5 years to alendronate or placebo. The results of a preplanned interim analysis at 3 years are reported herein. Participants were re-randomized to alendronate 10 mg/day (30%), alendronate 5 mg/day (30%), or placebo (40%). All participants were encouraged to take a calcium (500 mg/day) and vitamin D (250 IU/day) supplement. The primary outcome was change in total hip BMD. Secondary endpoints included change in lumbar spine BMD and change in markers of bone turnover (bone-specific alkaline phosphatase and urinary type I collagen cross-linked N-telopeptide). RESULTS: Among the women who had prior alendronate therapy in FIT, further therapy with alendronate (5 and 10 mg groups combined) for 3 years compared with placebo maintained BMD at the hip (2.0% difference; 95% CI, 1.6-2.5%) and further increased BMD at the spine (2.5% difference; 95% CI, 1.9-3. 1%). Markers of bone turnover increased among women discontinuing alendronate, whereas they remained stable in women continuing alendronate. Cumulative increases in BMD at the hip and spine and reductions in bone turnover from 8.6 years earlier at FIT baseline were greater for women continuing alendronate compared with those discontinuing alendronate. However, among women discontinuing alendronate and taking placebo in the extension, BMD remained higher and reduction in bone turnover was greater than values at FIT baseline. CONCLUSIONS: Compared with women who stopped alendronate after an average of 5 years, those continuing alendronate maintained a higher BMD and greater reduction of bone turnover, showing benefit of continued alendronate treatment on BMD and bone turnover. On discontinuation of alendronate therapy, rates of change in BMD at the hip and spine resumed at the background rate, but discontinuation did not result in either accelerated bone loss or a marked increase in bone turnover, showing persistence of alendronate's effects on bone. Data on the effect of continuation versus discontinuation on fracture risk are needed before making definitive recommendations regarding the optimal length of alendronate treatment.

Aged↗

Evidence-based public health: an evolving concept.

Evidence-based public health (EBPH) has been proposed as a practice model that builds upon the success of evidence-based medicine (EBM). EBM has been described as a more scientific and systematic approach to the practice of medicine. It has enhanced medical training and practice in many settings. Both EBM and EBPH systematically use data, information, and scientific principles to enhance clinical care and population health, respectively. In this paper, we review the evolution of EBPH, propose a new definition for EBPH, and discuss developments that may support its further advancement.

Evidence-Based Medicine↗

Factors promoting consistent adherence to safe needle precautions among hospital workers.

OBJECTIVE: To examine organizational factors and occupational characteristics associated with adherence to occupational safety guidelines recommending never recapping needles. DESIGN: Mail surveys were conducted with healthcare workers (HCWs) and infection control professionals (ICPs). SETTING: The surveys were conducted at all non-federal general hospitals in Iowa, except one tertiary-care hospital. Survey data were linked to annual survey data of the American Hospital Association (AHA). PARTICIPANTS: HCWs were sampled from statewide rosters of physicians, nurses, and laboratory workers in Iowa. Eligible HCWs worked in a setting and position in which they were likely to routinely handle needles. ICPs at all hospitals in the state were surveyed. RESULTS: Ninety-nine ICPs responded (79% response rate). AHA data were available for all variables from 84 (85%) of the hospitals. Analyses were based on 1,454 HCWs who identified one of these hospitals as their primary hospital (70% response rate). Analyses were conducted using multiple logistic regression. Positive predictors of consistent adherence included infection control personnel hours per full-time-equivalent employee (odds ratio [OR], 1.03), frequency of standard precautions education (OR, 1.11), facilities providing personal protective equipment (OR, 1.82), facilities using needleless intravenous systems (OR, 1.42), and management support for safety (OR, 1.05). Negative predictors were use of "blood and body fluid precautions" isolation category (OR, 0.74) and increased job demands (OR, 0.90). CONCLUSION: Healthcare organizations can improve staff safety by investing wisely in educational programs regarding approaches to minimize these risks, providing protective equipment, and eliminating the use of blood and body fluid precautions as an isolation policy.

Equipment Design↗

Everyday activity predicts bone geometry in children: the iowa bone development study.

PURPOSE: Bone adapts to changing mechanical loads by altering the structure appropriately. These adaptations should be evident in the bone cross-sectional area (CSA) and section modulus (Z), indices of axial and bending strength, respectively. In this cross-sectional study, we investigated associations between physical activity, CSA, and Z in 467 young children (mean age 5.2 yr). We also examined whether lean tissue mass, which is predominantly muscle, mediates the relationship between physical activity and bone structural measures. METHODS: Physical activity was assessed using accelerometry and questionnaire. Proximal femur measures of the neck, intertrochanteric, and shaft CSA (cm) and Z (cm) were derived from dual-energy x-ray absorptiometry (DXA) scans using the Hip Structure Analysis program. Total body lean mass (kg) was also measured using DXA. RESULTS: Boys were more physically active than girls. Boys also had greater CSA, Z, and lean mass than girls. At each region, time spent in vigorous activity was positively and consistently associated with CSA and Z in boys and girls (r = 0.19 to 0.32). After adjustment for age, body mass, and height, vigorous activity explained, on average, 6.9% of the variability in CSA and Z. With additional adjustment for lean mass, vigorous activity explained 3.7% of the remaining variability in CSA and Z. CONCLUSION: This study demonstrates that everyday amounts of physical activity in healthy, normal children are associated with bone geometry and that differences in lean mass explain some, but not all, of this association. This suggests that, even in young, nonathletic children, bone may adapt to physical activity by structurally remodeling.

Anthropometry↗

Percutaneous injury, blood exposure, and adherence to standard precautions: are hospital-based health care providers still at risk?

To examine factors associated with blood exposure and percutaneous injury among health care workers, we assessed occupational risk factors, compliance with standard precautions, frequency of exposure, and reporting in a stratified random sample of 5123 physicians, nurses, and medical technologists working in Iowa community hospitals. Of these, 3223 (63%) participated. Mean rates of hand washing (32%-54%), avoiding needle recapping (29%-70%), and underreporting sharps injuries (22%-62%; overall, 32%) varied by occupation (P<.01). Logistic regression was used to estimate the adjusted odds of percutaneous injury (aOR(injury)), which increased 2%-3% for each sharp handled in a typical week. The overall aOR(injury) for never recapping needles was 0.74 (95% CI, 0.60-0.91). Any recent blood contact, a measure of consistent use of barrier precautions, had an overall aOR(injury) of 1.57 (95% CI, 1.32-1.86); among physicians, the aOR(injury) was 2.18 (95% CI, 1.34-3.54). Adherence to standard precautions was found to be suboptimal. Underreporting was found to be common. Percutaneous injury and mucocutaneous blood exposure are related to frequency of sharps handling and inversely related to routine standard-precaution compliance. New strategies for preventing exposures, training, and monitoring adherence are needed.

Blood-Borne Pathogens↗

Gene polymorphisms, bone mineral density and bone mineral content in young children: the Iowa Bone Development Study.

We examined the association of candidate gene polymorphisms with bone mineral density (BMD) and bone mineral content (BMC) in a cohort of 428 healthy non-Hispanic white children participating in the Iowa Bone Development Study, a longitudinal study of determinants of bone accrual in childhood. BMD and BMC measurements of the hip, spine and whole body were made using a Hologic 2000 Plus densitometer in 228 girls and 200 boys ages 4.5-6.5 years. Genotypes at 14 loci representing eight candidate genes [type I collagen genes (COL1A1 and COL1A2), osteocalcin, osteonectin, osteopontin, vitamin D receptor (VDR), estrogen receptor (ER), androgen receptor (AR)] were determined. Gender-specific and gender-combined prediction models for bone measures that included age, weight, height (and gender) were developed using multiple linear regression analysis. COL1A2 and osteocalcin genotypes were identified as having the strongest and most consistent association with BMD/BMC measures. Osteonectin, osteopontin and VDR translation initiation site polymorphisms were associated with some individual bone measures, but none of the associations was as consistent as those identified for the COL1A2 and osteocalcin genes. No association was identified with COL1A1 (RsaI and Sp1), VDR (BsmI) and ER polymorphisms (PvuII, XbaI, TA) and BMD/BMC. However, we identified significant gene-by-gene interaction effects involving the ER and both VDR and osteocalcin, which were associated with BMD/BMC. Our data suggest that genetic variation at multiple genetic loci is important in bone accrual in children. Moreover, the combination of genotypes as several loci may be as important as a single genotype for determining BMD and BMC.

Anthropometry↗

Factors affecting the pullout strength of self-drilling and self-tapping anterior cervical screws.

STUDY DESIGN: A biomechanical comparison of 12-, 14-, and 16-mm self-tapping and self-drilling screws in cadaveric cervical spines was performed. OBJECTIVE: This study compared self-drilling and self-tapping screw designs used in anterior cervical locking plates in terms of insertion torque and pullout strength. In addition to screw design, the effects of screw length (12, 14, and 16 mm) and bone mineral density were examined. METHODS: A total of 201 screws were implanted and tested. Nineteen cadaver spine specimens (C2 through C7) were radiographed and their bone mineral density measured. In each vertebral level, two screws of the same length were implanted and their insertion torque measured. One of each screw design (self-drilling or self-tapping) was randomly placed in each vertebra for side-by-side comparison. Vertebrae then were individually potted and mounted on an MTS machine for accurate measurement of maximum pullout strength. RESULTS: Pullout strength was strongly related to screw length ( = 0.0002). There was no significant difference in pullout strength between the self-drilling and self-tapping screw designs at any length ( = 0.9352). A significant correlation ( </= 0.0077) exists between insertion torque and bone mineral density for the self-drilling and self-tapping 14- and 16-mm screws. A significant correlation exists between pullout strength and bone mineral density for 14- and 16-mm screw lengths of both screw types ( < 0.0001). CONCLUSIONS: It would appear that the longest screw feasible should always be used clinically for maximum pullout strength. There is no difference in pullout strength between self-drilling and self-tapping screws. Bone mineral density significantly influences screw performance.

Adult↗

Factors associated with mode of transport to acute care hospitals in rural communities.

This study identifies factors associated with mode of transport to rural hospitals. We evaluated 11,541 trauma patient visits that came by ground ambulance or private vehicle to the Emergency Department of one of six northwest Iowa rural hospitals. We performed univariate analyses and logistic regression analyses to identify factors associated with mode of transport for each severity level (fatal, major and minor). For major/fatal injuries, we found that those aged 65 years and over were 3.6 (95% CI = 2.7-4.9) times more likely to use ambulances than those under 15. Motor vehicle traffic injuries and hip fractures were also associated with ambulance usage, while arm fractures and farm-related injuries were not. We conclude that for major/fatal injuries, older persons, those injured from high velocity causes, and those with hip fractures are more likely to use an ambulance. Emergency Medical Services may improve the community's ambulance utilization by providing public education (e.g., proper use of 911 and injury severity recognition), and by collaborating with dispatch, the local community and health care providers. Further study of the community's and individuals' decision-making factors determining mode of transportation is needed.

Adolescent↗

Prognostic factors for mortality following interhospital transfers to the medical intensive care unit of a tertiary referral center.

OBJECTIVE: To describe characteristics of patients transferred from outside hospitals to a tertiary medical intensive care unit and to identify patient-level and system-level prognostic factors. DESIGN: Retrospective cohort study. SETTING: Tertiary university hospital. PATIENTS: We studied 3,347 patients who were transferred to the medical intensive care unit from outside hospitals from January 1990 through September 1999. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data collected included patient demographics, insurance type, discharge diagnoses, length of stay, mortality, admitting service, and distance traveled. The Charlson Comorbidity Score was used to adjust for comorbidity and the diagnostic related group risk level for risk of adverse outcome. Multivariate logistic models of early mortality (<72 hrs) and overall hospital mortality rate were developed. The most common major diagnostic categories included neurologic (10%), respiratory (10%), digestive diseases (10%), and drug overdose (10%). Most patients (70%) were transferred from >60 miles away. Mean medical intensive care unit length of stay was 5.3 days vs. 3.9 days for nontransfer patients. Transfer patients accounted for 49% of medical intensive care unit admits and 56% of intensive care unit patient-days. The overall mortality rate for transfer patients to the medical intensive care unit was 25% (95% confidence interval, 23-26), significantly higher than the 21% (95% confidence interval, 19-22) mortality rate among those admitted directly. Independent prognostic factors for early death (<72 hrs) included male gender, summer season, admitting service, diagnostic related group level, Charlson Comorbidity Score, insurance type, and major diagnostic category. Independent prognostic factors for overall hospital mortality rate included length of stay, medical complication, distance traveled, insurance type, and major diagnostic category. CONCLUSIONS: Interhospital transfers to the medical intensive care unit are patients at high risk for mortality and other adverse outcomes. System-level and patient-level characteristics influence both early and overall hospital mortality rates. These variables should be considered when risk stratifying medical intensive care unit patients and in studying outcomes of care.

Adult↗

In vitro biomechanical comparison of pedicle screws, sublaminar hooks, and sublaminar cables.

OBJECT: Three types of posterior thoracolumbar implants are in use today: pedicle screws, sublaminar titaniumcables, and sublaminar hooks. The authors conducted a biomechanical comparison of these three implants in human cadaveric spines. METHODS: Spine specimens (T5-12) were harvested, radiographically assessed for fractures or metastases, and their bone mineral density (BMD) was measured. Individual vertebrae were disarticulated and fitted with either pedicle screws, sublaminar cables, or bilateral claw hooks. The longitudinal component of each construct consisted of bilateral 10-cm rods connected with two cross-connectors. The vertebral body was embedded in cement, and the rods were affixed to a ball-and-socket apparatus for the application of a distraction force. The authors analyzed 1) 20 vertebrae implanted with screws; 2) 20 with hooks, and 3) 20 with cables. The maximum pullout (MPO) forces prior to failure (mean +/- standard deviation) for the screw, hook, and cable implants were 972 +/- 330, 802 +/- 356, and 654 +/- 248 N, respectively (p = 0.0375). Cables allowed significantly greater displacement (6.80 +/- 3.95 mm) prior to reaching the MPO force than hooks (3.73 +/- 1.42 mm) and screws (4.42 +/- 2.15 mm [p = 0.0108]). Eleven screw-implanted vertebrae failed because of screw pullout. All hook-and-cable-implanted vertebrae failed because of pedicle, middle column, or laminar fracture. CONCLUSIONS: These findings suggest that screws possess the greatest pullout strength of the three fixation systems. Sublaminar cables are the least rigid of the three. When screw failure occurred, the mechanism was generally screw back-out, without vertebral fractures.

Adult↗