ABSTRACT
Three aquaporin water channel proteins, AQP3, AQP4 and AQP15 were localized to cells within the kidney of the spiny dogfish, Squalus acanthias, using an immunohistochemical approach. Dogfish kidney has two zones, the bundle zone (including five nephron segment bundles) and the sinus zone (with two major loops). In order to discriminate between the two loops, the cilia occurring in the first proximal/intermediate loop were labeled with two antibodies including an anti-acetylated tubulin antibody. The second late distal tubule loop (LDT) was identified, as the nephron in that region has no luminal cilia. Strong staining of the rabbit anti-dogfish AQP3, AQP4 (AQP4/2) or AQP15 polyclonal antibodies localized to LDT tubules. These antibodies were further co-stained with a mouse anti-Na+,K+-ATPase a5 monoclonal antibody, as Na+,K+-ATPase has previously been suggested to localize to the early distal tubule (EDT) and LDT and a mouse anti-NKCC T4 antibody, as NKCC2 was previously suggested to be located in the EDT and the second half of the LDT. In the LDT, strong AQP4/2 and AQP15 antibody staining localized together with the strong Na+,K+-ATPase antibody staining, whereas strong AQP3 antibody staining was largely separate but with an overlapping distribution. Very low levels of AQP4/2 antibody basal membrane staining was also detected in the first proximal /intermediate loop of the sinus zone. There was no mouse anti-NKCC T4 antibody staining apparent in the LDT. In the convoluted part of the bundle zone, the AQP4/2 and Na+,K+-ATPase but not the AQP3 or AQP15 antibodies stained tubule segments, with both AQP4/2 and Na+,K+-ATPase staining the EDT, and with low-level AQP4/2 staining of two other tubules of the bundle, which were most likely to be the proximal 1a (PIa) and intermediate II (IS II) tubules. The AQP4/2 antibody also stained the EDT in the straight bundle zone. The mouse anti-NKCC T4 antibody stained the apical region of EDT tubules in the convoluted bundle zone, suggesting that the antibody was binding to the NKCC2 cotransporter. The AQP15 antibody appeared to bind to the peritubular sheath surrounding bundles in the bundle zone. Due to the AQP4/2 antibody staining in the EDT that immediately proceeds and continues into the LDT, this suggested that the strong AQP4/2, AQP15 and Na+,K+-ATPase antibody staining was located at the beginning of the LDT and therefore the strong AQP3 was located at the end of the LDT. The staining of all three AQP antibodies was blocked by the peptide-antigen used to make each one, suggesting that all the staining is specific to each antibody.
Subject(s)
Aquaporins , Squalus acanthias , Animals , Dogfish , Kidney , Mice , Nephrons , RabbitsABSTRACT
Continuous delivery of oxygen therapy has been observed to improve healing for individuals with an advanced diabetic foot ulcer (DFU). However, this intervention requires the purchasing of an oxygen delivery device and moist dressings. It is unknown whether this upfront financial investment represents good value for money. Thus the aim of this project is to evaluate the cost-effectiveness of treating advanced DFU using continuous delivery of oxygen compared with negative pressure wound therapy from the perspective of the public health care payer in Ontario, Canada. A microsimulation model was constructed with inputs from peer-reviewed journal publications and publicly available reports. The 5-year costs and quality-adjusted life-years were compared between treatment and comparator. Sensitivity analyses were conducted to evaluate the robustness of results. The model predicted that continuous delivery of oxygen would cost $4800 less compared with negative pressure wound therapy and increased quality-adjusted life years by 0.025. Lower cost and improved outcomes were observed in most scenario analyses. The results of this economic evaluation suggest that CDO therapy may reduce health care economic burden with a modest increase in quality of life outcomes. Health care decision-makers should consider the inclusion of CDO for the treatment of DFU.
Subject(s)
Diabetes Mellitus , Diabetic Foot , Cost-Benefit Analysis , Diabetic Foot/therapy , Humans , Ontario , Oxygen , Quality of LifeABSTRACT
BACKGROUND: Deep Tissue Pressure Injury (DTI) occurs in the tissues underlying the skin that may not have visible signs of skin breakdown and may be detected by ultrasound. The optimal position for ischial region ultrasound image acquisition to facilitate assessment of the tissue proximal to the ischias not been determined. OBJECTIVE: To evaluate the mean difference in geometric and grey scale measures of tissues overlying the ischial tuberosity (IT) acquired from ultrasound images in supine and lateral recumbent simulated sitting positions from adults with spinal cord impairment (SCI). METHODS: Nine individuals (3 acute and 6 chronic) with SCI or disease with neurological level of injury C4-T12 and AIS A-D and who used a wheelchair for mobility were recruited and underwent ultrasound acquisition in the supine and lateral recumbent positions. One participant was imaged twice on a separate day. Three images from the left (nâ¯=â¯8) and right (nâ¯=â¯2) IT were scanned using a 6 - 18â¯MHz linear ultrasound probe (Acuson S2000) with participants' hips and knees flexed to 90° in both the supine and lateral recumbent positions using a single rater protocol. MATLAB Image Processing Toolbox with a customized script was used to obtain mean and maximal thickness, echogenicity and contrast of skin, subcutaneous tissue and muscle. Wilcoxon Signed Rank Test and Bland Altman analysis was used to determine if there were differences between the two image acquisition positions and to construct limits of agreement. RESULTS: Thickness and contrast measures were similar in the supine and lateral recumbent positions (pâ¯>â¯0.05). Muscle echogenicity was lower in the supine position (pâ¯=â¯0.04). CONCLUSION: There is agreement in geometric and grey scale measures of tissues over the IT between the supine and lateral recumbent positions with the exception of muscle echogenicity, which was lower in the supine position. Since DTI is thought to originate in the muscle and echogenicity plays in a role in abnormal tissue imaging diagnosis, further studies are recommended to determine the impact of body position on muscle echogenicity prior to being used in prospective studies.
Subject(s)
Ischium/blood supply , Patient Positioning/standards , Skin/blood supply , Ultrasonography/methods , Aged , Australia , Canada , Cohort Studies , Female , Humans , Longitudinal Studies , Male , Middle Aged , Patient Positioning/statistics & numerical data , Pressure/adverse effects , Prospective Studies , Spinal Cord Injuries/complications , Spinal Cord Injuries/physiopathologyABSTRACT
Optimal pressure injury (ulcer) management by the inter-professional team requires appropriate health care system and organisational resources, infrastructure, and policies. A systematic review was conducted on pressure injury care-related education and health care system-/organisation-level strategies. A search for relevant articles published between January 2006 and October 2014 was applied to 8 databases. Ultimately, 22 articles pertaining to education and training and 12 articles pertaining to health care system and organisation supports for pressure injury care were included in the systematic review. A lack of pressure injury assessment and management knowledge by health care professionals was an overriding theme in the education literature. Some of the methods preferred for pressure injury education among nurses and physicians included information technology (eg, e-learning) with technology support and the use of high-quality wound pictures. Although the evidence is scarce, the literature did highlight specific system- and organisation-level barriers and enablers that influence practice change, including inter-professional communication and human resource investments. In conclusion, (1) the current evidence on the education and system-level enablers, barriers, and strategies to optimise pressure injury best practices requires further investigation, and (2) multi-faceted, up-stream, evidence-based approaches for pressure injury care are essential to improve health care and patient-related outcomes.
Subject(s)
Clinical Competence/standards , Health Personnel/standards , Practice Guidelines as Topic , Pressure Ulcer/therapy , Adult , Female , Humans , Male , Middle AgedABSTRACT
PURPOSE: This investigation examined the trends for gender-based advancement in academic surgery by performing a comparative analysis of the rate of change in the percentage of medical students, surgery residents, and full professors of surgery who are women. METHODS: All available Women in Medicine Annual Reports were obtained from the American Association of Medical Colleges (AAMC). The gender compositions of medical graduates, surgery residents, and full professors were plotted. Binomial and linear trendlines were calculated to estimate the year when 50% of surgery full professors would be women. Additionally, the percentage distribution of men and women at each professorial rank was determined from 1995 to 2009 using these reports to demonstrate the rate of academic advancement of each gender. RESULTS: The slope of the line of increase for women full professors is significantly less than for female medical students and for female general surgery residents (0.36, compared with 0.75 and 0.99, respectively). This predicts that the earliest time that females will account for 50% of full professors in surgery is the year 2096. When comparing women and men in academic ranks, we find that women are much less likely than men to be full professors. CONCLUSIONS: The percentage of full professors in surgery who are women is increasing at a rate disproportionately slower than the increases in female medical students and surgery residents. The rates of increase in female medical students and surgery residents are similar. The disproportionately slow rate of increase in the number of female full professors suggests that multiple factors may be responsible for this discrepancy.
Subject(s)
Faculty, Medical/statistics & numerical data , General Surgery , Physicians, Women/statistics & numerical data , Physicians, Women/trends , Adult , Female , Humans , Male , Sex Distribution , Surveys and Questionnaires , United StatesABSTRACT
People undergoing orthopedic surgery receive care at many points along the healthcare continuum. Although heel pressure ulcer (HPU) incidence in the orthopedic population has been reported to be 13.3%, information is limited. The purpose of this prospective observational study was to evaluate: 1) the cumulative incidence of HPUs in orthopedic patients across the continuum of care, and 2) the outcome of HPUs once they occurred. Of the 72 study participants (average age 76 +/- 16 years, 60% women, 53% required surgery for hip fractures), 57 were recruited consecutively upon admission to a rehabilitation center from one of two acute care facilities and 15 were assessed upon admission to one of the acute care sites and at discharge to the home. All but two study participants were followed-up in the community 1 month after discharge from the acute care or rehabilitation facility. Medical charts were reviewed and study participants underwent a bedside assessment, with direct examination of both heels and staging of the ulcer at admission and discharge. The cumulative incidence of HPUs was 17% (95% CI 8%-26%). All ulcers were identified upon admission to the rehabilitation center; 41% of HPUs were either suspected deep tissue injury (sDTI) or unstageable. Both of the Stage I and two of the five Stage II ulcers were resolved at the time of follow-up; three of the five sDTI or unstageable ulcers were unresolved. HPUs occurred in 17% of people undergoing orthopedic procedures. All ulcers occurred in acute care and severe ulcers persisted while patients received rehabilitation and community care. This is the first study to follow orthopedic patients across the continuum of care.
Subject(s)
Heel/pathology , Orthopedic Procedures/adverse effects , Ulcer/etiology , Aged , Aged, 80 and over , Female , Humans , Incidence , Male , Middle Aged , Prospective StudiesABSTRACT
OBJECTIVE: To investigate whether electric stimulation therapy (EST) administered as part of a community-based, interdisciplinary wound care program accelerates healing of pressure ulcers in people with spinal cord injury (SCI). DESIGN: Single-blind, parallel-group, randomized, controlled, clinical trial. SETTING: Community-based home care setting, Ontario, Canada. PARTICIPANTS: Adults (N=34; mean age +/- SD, 51+/-14y) with SCI and stage II to IV pressure ulcers. INTERVENTIONS: Subjects were stratified based on wound severity and duration and randomly assigned to receive either a customized, community-based standard wound care (SWC) program that included pressure management or the wound care program plus high-voltage pulsed current applied to the wound bed (EST+SWC). MAIN OUTCOME MEASURES: Wound healing measured by reduction in wound size and improvement in wound appearance at 3 months of treatment with EST+SWC or SWC. RESULTS: The percentage decrease in wound surface area (WSA) at the end of the intervention period was significantly greater in the EST+SWC group (mean +/- SD, 70+/-25%) than in the SWC group (36+/-61%; P=.048). The proportion of stage III, IV, or X pressure ulcers improving by at least 50% WSA was significantly greater in the EST+SWC group than in the SWC group (P=.02). Wound appearance assessed using the photographic wound assessment tool was improved in wounds treated with EST+SWC but not SWC alone. CONCLUSIONS: These results demonstrate that EST can stimulate healing of pressure ulcers of people with SCI. EST can be incorporated successfully into an interdisciplinary wound care program in the community.
Subject(s)
Electric Stimulation Therapy , Pressure Ulcer/therapy , Spinal Cord Injuries/complications , Adult , Aged , Female , Humans , Male , Middle Aged , Paraplegia/complications , Pressure Ulcer/etiology , Residence Characteristics , Single-Blind Method , Wound HealingABSTRACT
To implement and evaluate a heel pressure ulcer prevention program (HPUPP) for orthopaedic patients. Program development of HPUPP involved input from administrators, staff and adult patients on an orthopaedic service in an academic tertiary care facility, located in a small urban centre in Canada. Prospective evaluation was conducted. Consensus exercises with clinical staff and administrators (Delphi and Nominal group) were used to, evaluate current practices, select a heel protective device, and develop key aspects of the HPUPP. HPUPP involved an individualised, bedside, staff education program, a team approach to improve patient mobility and use of a heel protective device. A 2-inch foam wedge covered in washable vinyl was placed at the foot of all beds on the orthopedic service. After the program was implemented, the incidence of heel pressure ulcers was 0%, which was a significant reduction compared with pre-implementation levels [13.8% (95% confidence interval 8-18%)]. Key components of the program success were initial and ongoing support from administration and surgeons, incorporation of feedback from clinical staff and patients, and keeping the program simple. Heel PU can be prevented in most orthopaedic patients using a universal heel PU prevention program.
Subject(s)
Heel , Patient Positioning/instrumentation , Pressure Ulcer/prevention & control , Canada , Delphi Technique , Equipment Design , Hospitals, University , Humans , Organizational Case StudiesABSTRACT
Heel pressure ulcers (PU) are a major concern in orthopedic patients. A prospective 6-month study was conducted in an acute care hospital in Canada to determine the incidence of heel PU in an orthopedic population, evaluate the effect of patient and care variables on heel PU incidence, and describe the natural history/sequelae of Stage I heel PU. One hundred and fifty (150) patients (average age 70.6 years) admitted for elective orthopedic surgery or treatment of a fractured hip participated in the study. A direct heel skin assessment was performed following admission and before discharge. Patients with a Stage I ulcer were assessed or contacted 1 week following discharge. The incidence of heel PU in this population was 13.3% CI (range 8% to 19%). Incidence was 16% in the hip fracture and 13% in the elective surgery group. PU incidence in the hip fracture group was significantly lower (P = 0.016) for patients receiving heel pressure relief measures (pillows, rolled sheets). In the elective surgery group, PU incidence rates were higher for patients with respiratory disease, lower hemoglobin, low pulse rate, and altered mental status (P <0.05). When both patient groups were combined, only the presence or absence of respiratory disease significantly affected PU incidence. Length of stay was an average of 3 days longer in all groups with a heel PU but the difference was not statistically significant. One week following discharge, 13 of the 17 (76%) Stage I heel PU had resolved, one remained unchanged, and two were assessed as deep tissue injury (11%) and one as Stage II. These incidence rates are similar to those reported in other countries and confirm that efforts to reduce heel PU incidence rates are needed.
Subject(s)
Heel , Hospitals , Pressure Ulcer/epidemiology , Aged , Humans , Incidence , Risk FactorsABSTRACT
Pressure ulcers substantially affect frail older adults, as well as their family caregivers, nurses, and the healthcare system at large. This article uses the World Health Organization's International Classification of Functioning, Disability and Health as a framework to discuss pressure ulcers in frail older adults. Pressure ulcers and frailty are defined and prevalence and incidence figures are reviewed. The connection is made between pressure ulcers and frailty using a model of shared risk factors and these medical syndromes are described as a synergistic relationship. In addition, the relevance to practice is discussed.
Subject(s)
Frail Elderly , Pressure Ulcer/prevention & control , Aged , Geriatric Assessment , Humans , Models, Theoretical , Pressure Ulcer/nursing , Rehabilitation Nursing , Risk FactorsABSTRACT
A shared language and conceptual framework is essential to successful interprofessional collaboration. The World Health Organization's International Classification of Functioning, Disability and Health (ICF) provides a shared language and conceptual framework that transcends traditional disciplinary boundaries. This paper will familiarize readers with the ICF and describe the biopsychosocial perspective that is adopted in its conceptual framework and language. The presentation of a case study will illustrate how the ICF can enhance interprofessional learning by promoting a multidimensional perspective of an individual's health concerns. The case study will also highlight the value of the shared language and conceptual framework of the ICF for interprofessional collaboration. It is argued that a strong foundation in the principles exemplified by the ICF may serve to enhance interprofessional communication, and in so doing, encourage involvement in interprofessional collaboration and healthcare.
Subject(s)
Activities of Daily Living/classification , Disabled Persons/classification , Education, Medical , International Classification of Diseases , Interprofessional Relations , Models, Theoretical , Aged, 80 and over , Health Status , Humans , Male , Ontario , World Health OrganizationABSTRACT
Ultraviolet light C (light wavelength 200 nm to 290 nm) has been shown to kill cultures of antibiotic resistant strains of bacteria such as methicillin-resistant Staphylococcus aureus. To evaluate the ability of ultraviolet light C to reduce the amount and type of bacteria present in chronically infected ulcers, as well as to establish the test-retest reliability of the semi-quantitative swab technique, a prospective, one-group, pre-post treatment study was conducted among patients receiving treatment in several in- and outpatient facilities and nursing homes. Individuals with chronic ulcers exhibiting at least two signs of infection and critically colonized with bacteria (n = 22) received a single 180-second treatment using an ultraviolet light C lamp (wavelength = 254 nm) placed 1 inch from the wound bed. Semi-quantitative swabs taken immediately before and after UVC treatment were used to assess changes in the bacterial bioburden present within the wound bed. Results demonstrated excellent test-retest reliability of the semi-quantitative swab technique used to evaluate the type and amount of bacteria present in chronic wounds (Cohen's kappa = 0.92). Assessment of wound bioburden using semi-quantitative swabs revealed a statistically significant (P <0.0001) reduction in the relative amount of bacteria following a single treatment of ultraviolet light C. The greatest reduction in semi-quantitative swab scores following ultraviolet light C treatment were observed for wounds colonized with the bacteria Pseudomonas aeruginosa and wounds colonized with only one species of bacteria. Significant (P <0.05) reductions in the relative amount of bacteria also were observed in 12 ulcers in which methicillin-resistant Staphylococcus aureus was present. These results confirm previous laboratory studies and demonstrate that ultraviolet light C can kill bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus present in superficial layers of chronic wounds.
Subject(s)
Skin Diseases, Bacterial/microbiology , Skin Diseases, Bacterial/therapy , Specimen Handling/methods , Ultraviolet Therapy , Wound Infection/microbiology , Wound Infection/therapy , Aged , Colony Count, Microbial , Female , Humans , Leg Ulcer/microbiology , Leg Ulcer/therapy , Male , Methicillin Resistance , Pressure Ulcer/microbiology , Pressure Ulcer/therapy , Prospective Studies , Reproducibility of Results , Staphylococcal Infections/therapyABSTRACT
OBJECTIVE: To develop and validate an assessment tool--the Leg Ulcer Measurement Tool (LUMT)--that would be able to detect changes in the appearance of lower extremity ulcers. SUBJECTS: Twenty-two subjects with chronic leg ulcers of various etiologies (arterial, venous, diabetes) participated in the validation study. DESIGN: An interdisciplinary panel consisting of 9 local wound care specialists confirmed content validity. Concurrent criterion validity was determined by correlation of the size domain (1 of 14 clinician-rated domains in the LUMT) with acetate tracing measurement of wound surface area. Reliability was determined using repeated assessments by 4 wound care specialist and 2 inexperienced evaluators; responsiveness was determined using monthly reassessments by a single rater for 4 months. RESULTS: Concurrent criterion validity was r = 0.82. Excellent values of intrarater and interrater reliability (ICC > 0.75) were obtained for total LUMT scores and for many of the 14 individual domains; however, several domains were found to be less reproducible. The LUMT detected change in wound status over time (responsiveness coefficient = 0.84). CONCLUSION: The LUMT can be used by 1 or more assessors, with relatively little previous training, to make reproducible evaluations of lower extremity ulcer appearance and to document change in appearance over time. The LUMT represents a novel assessment tool specifically designed and validated for clinical or research use on chronic leg ulcers.
Subject(s)
Physical Examination/methods , Varicose Ulcer/diagnosis , Aged , Analysis of Variance , Female , Humans , Male , Observer Variation , Reproducibility of ResultsABSTRACT
Military training exercises are conducted routinely in the Mojave Desert. To determine whether assignment in this desert environment increases risk of respiratory illnesses, hospitalization rates were compared between two matched cohorts of soldiers during three intervals of follow-up during a 10-year surveillance period. The exposed cohort (N = 21,543) included all soldiers who were ever assigned to the Mojave Desert during the surveillance period. The control cohort (N = 86,172) included soldiers matched on demographic characteristics who were never assigned to the Mojave Desert during the surveillance period. Three follow-up intervals ("before," "during," "after") were defined relative to times when exposed soldiers were assigned to the desert. Rates of respiratory hospitalizations were similar between the cohorts for the "before" and "during" intervals but were higher in the exposed cohort for the "after" interval (rate ratio, 1.30; 95% confidence interval, 1.07-1.59). This difference was largely attributable to excess pneumonia and influenza hospitalizations in the exposed cohort. Healthy, young adults may have increased susceptibility to respiratory infectious illnesses after prolonged exposures to desert environments.
Subject(s)
Desert Climate/adverse effects , Military Personnel , Occupational Diseases/epidemiology , Respiratory Tract Diseases/epidemiology , Adolescent , Adult , Cohort Studies , Female , Hospitalization , Humans , Male , Occupational Diseases/etiology , Respiratory Tract Diseases/etiology , Retrospective StudiesABSTRACT
BACKGROUND AND PURPOSE: Electrical current has been recommended for use on chronic pressure ulcers; however, the ability of this modality to improve healing of other types of chronic ulcers is less well established. The purpose of this study was to examine the effect of high-voltage pulsed current (HVPC) on healing of chronic leg ulcers. SUBJECTS: Twenty-seven people with 42 chronic leg ulcers participated in the study. METHODS: The subjects were separated into subgroups according to primary etiology of the wound (diabetes, arterial insufficiency, venous insufficiency) and then randomly assigned to receive either HVPC (100 microseconds, 150 V, 100 Hz) or a sham treatment for 45 minutes, 3 times weekly, for 4 weeks. Wound surface area and wound appearance were assessed during an initial examination, following a 1- to 2-week period during which subjects received only conventional wound therapy, after 4 weeks of sham or HVPC treatment, and at 1 month following treatments. RESULTS: The results indicated that HVPC applied to chronic leg ulcers reduced the wound surface area over the 4-week treatment period to approximately one half the initial wound size (mean decrease=44.3%, SD=8.8%, range=2.8%-100%), which was over 2 times greater than that observed in wounds treated with sham units (mean decrease=16.0%, SD=8.9%, range=-30.3%-83.7%). DISCUSSION AND CONCLUSION: The results of the study indicate that HVPC administered 3 times a week should be considered to accelerate wound closure of chronic leg ulcers.
Subject(s)
Electric Stimulation Therapy , Leg Ulcer/rehabilitation , Adult , Aged , Aged, 80 and over , Analysis of Variance , Chronic Disease , Double-Blind Method , Female , Humans , Male , Middle Aged , Statistics, Nonparametric , Wound HealingABSTRACT
The prevalence of antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus is rapidly increasing in healthcare facilities and spreading to the community. Methicillin-resistant S. aureus colonize the skin and open wounds and can interfere with wound healing. Recent studies have shown that ultraviolet light C can kill antibiotic-resistant strains of bacteria such as methicillin-resistant S. aureus in both laboratory cultures and animal tissue. This clinical report describes the effects of ultraviolet light C on wound bioburden and closure in three people with chronic ulcers infected with methicillin-resistant S. aureus. In all three patients, ultraviolet light C treatment reduced wound bioburden and facilitated wound healing. Two patients had complete wound closure following 1 week of ultraviolet light C treatment. This case study suggests that ultraviolet light C is a promising adjunctive therapy for chronic wounds containing antibiotic-resistant bacteria such as methicillin-resistant S. aureus.
Subject(s)
Methicillin Resistance/radiation effects , Skin Ulcer/microbiology , Skin Ulcer/radiotherapy , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/radiation effects , Ultraviolet Therapy , Aged , Aged, 80 and over , Chronic Disease , Female , Humans , MaleABSTRACT
Bell's palsy is a relatively common disease characterized by the sudden onset of unilateral facial paralysis. Using a centralized surveillance system that contains demographic, military assignment, and medical encounter data of US military service members, the authors estimated rates, trends, and demographic correlates of risk of Bell's palsy during a 2-year period. Poisson regression was used to estimate the independent effects of climate, season, and latitude. From October 1997 to September 1999, there were 1,181 incident cases of Bell's palsy among US service members. The crude incidence rate was 42.77 per 100,000 person-years. Incidence rates increased with age and were higher among females, Blacks, Hispanics, married persons, and enlisted service members. Both climate (adjusted rate ratio for arid vs. nonarid climate = 1.34) and season (adjusted rate ratio for cold vs. warm months = 1.31) were independent predictors of risk of Bell's palsy. Latitude was not a statistically significant predictor when demographic, climate, and season effects were taken into account. The results are consistent with hypotheses regarding viral etiologies (e.g., reactivation of herpes simplex) of Bell's palsy.