Fracture Risk and Association With TDF Use Among People With HIV in Large Integrated Health Systems

BACKGROUND

Greater decline in bone health among people with HIV (PWH) has been documented but fracture risk and the impact of specific antiretroviral therapy (ART) regimens remain unclear.

SETTING

Retrospective analyses of electronic health record data from 3 US integrated health care systems.

METHODS

Fracture incidence was compared between PWH aged 40 years or older without prior fracture and demographically matched people without HIV (PWoH), stratified by age, sex, and race/ethnicity. Multivariable Cox proportional hazards models were used to estimate fracture risk associated with HIV infection. The association of tenofovir disoproxil fumarate (TDF) use and fracture risk was evaluated in a subset of PWH initiating ART.

RESULTS

Incidence of fracture was higher in PWH [13.6/1000 person-years, 95% confidence interval (CI): 13.0 to 14.3, n = 24,308] compared with PWoH (9.5, 95% CI: 9.4 to 9.7, n = 247,313). Compared with PWoH, the adjusted hazard ratio (aHR) for fracture among PWH was 1.24 (95% CI: 1.18 to 1.31). The association between HIV infection and fracture risk increased with age, with the lowest aHR (1.17, 95% CI: 1.10 to 1.25) among those aged 40-49 years and the highest aHR (1.89, 95% CI: 1.30 to 2.76) among those aged 70 years or older. Among PWH initiating ART (n = 6504), TDF was not associated with significant increase in fracture risk compared with non-TDF regimens (aHR: 1.18, 95% CI: 0.89 to 1.58).

CONCLUSIONS

Among people aged 40 years or older, HIV infection is associated with increased risk of fractures. Bone health screening from the age of 40 years may be beneficial for PWH. Large cohort studies with longer follow-up are needed to evaluate TDF effect and the potential benefit of early screening.

Dexamethasone Suppression Testing in a Contemporary Cohort with Adrenal Incidentalomas in Two U.S. Integrated Healthcare Systems

Autonomous cortisol secretion (ACS) from an adrenal adenoma can increase the risk for comorbidities and mortality. The dexamethasone suppression test (DST) is the standard method to diagnose ACS. A multi-site, retrospective cohort of adults with diagnosed adrenal tumors was used to understand patient characteristics associated with DST completion and ACS. Time to DST completion was defined using the lab value and result date; follow-up time was from the adrenal adenoma diagnosis to the time of completion or censoring. ACS was defined by a DST > 1.8 µg/dL (50 nmol/L). The Cox proportional hazards regression model assessed associations between DST completion and patient characteristics. In patients completing a DST, a logistic regression model evaluated relationships between elevated ACS and covariates. We included 24,259 adults, with a mean age of 63.1 years, 48.1% obese, and 28.7% with a Charlson comorbidity index ≥ 4. Approximately 7% (n = 1768) completed a DST with a completion rate of 2.36 (95% CI 2.35, 2.37) per 100 person-years. Fully adjusted models reported that male sex and an increased Charlson comorbidity index were associated with a lower likelihood of DST completion. Current or former smoking status and an increased Charlson comorbidity index had higher odds of a DST > 1.8 μg/dL. In conclusion, clinical policies are needed to improve DST completion and the management of adrenal adenomas.

Long-term effects of primary hyperparathyroidism and parathyroidectomy on kidney function

IMPORTANCE

Limited evidence supports kidney dysfunction as an indication for parathyroidectomy in asymptomatic primary hyperparathyroidism (PHPT).

OBJECTIVE

To investigate the natural history of kidney function in PHPT and whether parathyroidectomy alters renal outcomes.

DESIGN

Matched control study.

SETTING

A vertically integrated health care system serving 4.6 million patients in Southern California.

PARTICIPANTS

6058 subjects with PHPT and 16 388 matched controls, studied from 2000 to 2016.

EXPOSURES

Biochemically confirmed PHPT with varying serum calcium levels.

MAIN OUTCOMES

Estimated glomerular filtration rate (eGFR) trajectories were compared over 10 years, with cases subdivided by severity of hypercalcemia: serum calcium 2.62-2.74 mmol/L (10.5-11 mg/dL), 2.75-2.87 (11.1-11.5), 2.88-2.99 (11.6-12), and >2.99 (>12). Interrupted time series analysis was conducted among propensity-score-matched PHPT patients with and without parathyroidectomy to compare eGFR trajectories postoperatively.

RESULTS

Modest rates of eGFR decline were observed in PHPT patients with serum calcium 2.62-2.74 mmol/L (−1.0 mL/min/1.73 m2/year) and 2.75-2.87 mmol/L (−1.1 mL/min/1.73 m2/year), comprising 56% and 28% of cases, respectively. Compared with the control rate of −1.0 mL/min/1.73 m2/year, accelerated rates of eGFR decline were observed in patients with serum calcium 2.88-2.99 mmol/L (−1.5 mL/min/1.73 m2/year, P < .001) and >2.99 mmol/L (−2.1 mL/min/1.73 m2/year, P < .001), comprising 9% and 7% of cases, respectively. In the propensity score–matched population, patients with serum calcium >2.87 mmol/L exhibited mitigation of eGFR decline after parathyroidectomy (−2.0 [95% CI: −2.6 to −1.5] to −0.9 [95% CI: −1.5 to 0.4] mL/min/1.73 m2/year).

CONCLUSIONS AND RELEVANCE

Compared with matched controls, accelerated eGFR decline was observed in the minority of PHPT patients with serum calcium >2.87 mmol/L (11.5 mg/dL). Parathyroidectomy was associated with mitigation of eGFR decline in patients with serum calcium >2.87 mmol/L.

Increased risks of vertebral fracture and reoperation in primary spinal fusion patients who test positive for osteoporosis by Biomechanical Computed Tomography analysis

BACKGROUND CONTEXT

While osteoporosis is a risk factor for adverse outcomes in spinal fusion patients, diagnosing osteoporosis reliably in this population has been challenging due to degenerative changes and spinal deformities. Addressing that challenge, biomechanical computed tomography analysis (BCT) is a CT-based diagnostic test for osteoporosis that measures both bone mineral density and bone strength (using finite element analysis) at the spine; CT scans taken for spinal evaluation or previous care can be repurposed for the analysis.

PURPOSE

Assess the effectiveness of BCT for preoperatively identifying spinal fusion patients with osteoporosis who are at high risk of reoperation or vertebral fracture.

STUDY DESIGN

Observational cohort study in a multi-center integrated managed care system using existing data from patient medical records and imaging archives.

PATIENT SAMPLE

We studied a randomly sampled subset of all adult patients who had any type of primary thoracic (T4 or below) or lumbar fusion between 2005 and 2018. For inclusion, patients with accessible study data needed a preop CT scan without intravenous contrast that contained images (before any instrumentation) of the upper instrumented vertebral level.

OUTCOME MEASURES

Reoperation for any reason (primary outcome) or a newly documented vertebral fracture (secondary outcome) occurring up to 5 years after the primary surgery.

METHODS

All study data were extracted using available coded information and CT scans from the medical records. BCT was performed at a centralized lab blinded to the clinical outcomes; patients could test positive for osteoporosis based on either low values of bone strength (vertebral strength ≤ 4,500 N women or 6,500 N men) and/or bone mineral density (vertebral trabecular bone mineral density ≤ 80 mg/cm³ both sexes). Cox proportional hazard ratios were adjusted by age, presence of obesity, and whether the fusion was long (four or more levels fused) or short (3 or fewer levels fused); Kaplan-Meier survival was compared by the log rank test. This project was funded by NIH (R44AR064613) and all physician co-authors and author 1 received salary support from their respective departments. Author 6 is employed by, and author 1 has equity in and consults for, the company that provides the BCT test; the other authors declare no conflicts of interest.

RESULTS

For the 469 patients analyzed (298 women, 171 men), median follow-up time was 44.4 months, 11.1% had a reoperation (median time 14.5 months), and 7.7% had a vertebral fracture (median time 2.0 months). Overall, 25.8% of patients tested positive for osteoporosis and no patients under age 50 tested positive. Compared to patients without osteoporosis, those testing positive were at almost five-fold higher risk for vertebral fracture (adjusted hazard ratio 4.7, 95% confidence interval = 2.2-9.7; p<.0001 Kaplan-Meier survival). Of those positive-testing patients, those who tested positive concurrently for low values of both bone strength and bone mineral density (12.6% of patients overall) were at almost four-fold higher risk for reoperation (3.7, 1.9-7.2; Kaplan-Meier survival p<.0001); the remaining positive-testing patients (those who tested positive for low values of either bone strength or bone mineral density but not both) were not at significantly higher risk for reoperation (1.6, 0.7-3.7) but were for vertebral fracture (4.3, 1.9-10.2). For both clinical outcomes, risk remained high for patients who underwent short or long fusion.

CONCLUSION

In a real-world clinical setting, BCT was effective in identifying primary spinal fusion patients aged 50 or older with osteoporosis who were at elevated risks of reoperation and vertebral fracture.

Creating a Safety Net Process to Improve Colon Cancer Diagnosis in Patients With Rectal Bleeding

Background Failure to follow up on patients with rectal bleeding is common and may result in a delay in diagnosis of colorectal cancer or in missing high-risk adenomas. The authors' purpose was to create an electronic patient safety net for those diagnosed with rectal bleeding but who did not have colonoscopy to ensure proper detection of colonic abnormalities, including colon cancer. Methods In an integrated health delivery system serving < 4.6 million patients in Southern California, from 2014 to 2019, the authors electronically identified patients with rectal bleeding aged 45 to 80 years but with no recently documented colonoscopy. These cases were reviewed by a gastroenterologist to determine if colonoscopy was appropriate. The physician looked for known documentation as to the cause of rectal bleeding and verified no contraindications to the procedure; if indicated, testing was offered. Results Using the authors' safety net program, 1430 patients with rectal bleeding who needed and completed a colonoscopy were identified. Of those patients, 7.5% had an advanced adenoma or cancer, with a total of 20 cancers, and 34% had findings that warranted more frequent colonoscopy. Conclusions The authors designed a safety net system that was able to capture information on patients with rectal bleeding who had not had a colonoscopy and detected in 34% colonic pathology that would have otherwise gone undetected. The program did not require many resources to implement and had the ability to potentially prevent harm from reaching patients whose rectal bleeding did not get prompt workup. Other health systems and practices should consider implementing a similar system.

Outcomes post fragility fracture among members of an integrated healthcare organization

This study highlights an unmet need in osteoporosis management, suggesting that beyond bone mineral density and fracture history, gender, fracture type, and age should be considered for fracture risk assessment. Following fragility fracture, men, patients with a spine or hip fracture, and those aged ≥ 65 have a higher disease burden.

INTRODUCTION

The objective of this study was to characterize osteoporosis-related fracture incidence and identify predictors of subsequent fractures and mortality.

METHODS

This retrospective cohort study, conducted within Kaiser Permanente Southern California, included patients aged ≥ 50 years with qualifying fractures from 1/1/2007 to 12/31/2016, identified from diagnosis/procedure codes. Rates for fracture incidence, mortality, and resource utilization in the year post-fracture are reported. Associations between index fracture types and demographic/clinical characteristics, and mortality, subsequent fracture, and rehospitalization outcomes were estimated.

RESULTS

Of 63,755 eligible patients, 66.7% were ≥ 65 years and 69.1% female. Index fractures included nonhip/nonspine (64.4%), hip (25.3%), and spine (10.3%). Age-adjusted subsequent fracture rate/100 person-years was higher for those with an index spine (14.5) versus hip fracture (6.3). Hospitalization rate/100 person-years was highest for patients ≥ 65 (31.8) and for spine fractures (43.5). Men (vs women) had higher age-adjusted rates of hospitalization (19.4; 17.7), emergency room visits (73.8; 66.3), and use of rehabilitation services (31.7; 27.2). The 30-day age-adjusted mortality rate/100 person-years was 46.7, 32.4, and 15.5 for spine, hip, and nonspine/nonhip fractures. The 1-year age-adjusted mortality rate/100 person-years was 14.7 for spine and 15.6 for hip fractures. In multivariable analyses, spine and hip fractures (vs nonhip/nonspine fractures) were significant predictors of 1-year mortality, all-cause and osteoporosis-related hospitalization, and nursing home use (all P-values < 0.0001).

CONCLUSION

Morbidity is high in the year following a fragility fracture and men, patients with a spine or hip fracture, and those aged ≥ 65 have a greater disease burden.

Bisphosphonates and the risk of atypical femur fractures

Bisphosphonates are effective in reducing hip and other fractures. However, concerns about atypical femur fractures (AFFs) have contributed to substantially decreased bisphosphonate use, and hip fracture rates may be increasing. Despite this impact, important uncertainties remain regarding AFF risks including the association between bisphosphonate use and other risk factors such as BMD, age, weight, and race. To address this evidence gap, a cohort study of 196,129 women ≥50 years of age in the Southern California Kaiser Permanente HMO women (with ≥1 bisphosphonate prescription) were studied; the primary outcome was radiographically-adjudicated AFF between 2007 and 2017. Risk factors including bisphosphonate use and race were obtained from electronic health records. Multivariable Cox models were used for analysis. Benefit-risk was modeled for 1-10 years of bisphosphonates to compare fractures prevented vs. AFFs associated. Among 196,129 women, 277 (0.1%) sustained AFFs. After multivariable adjustment, AFF risk increased with longer bisphosphonate duration: hazard ratio (HR) increased from HR = 8.9 (95%CI: 2.8,28) for 3-5 years to HR = 43.5 (13.7138.1) for >8 years. Hip BMD, surprisingly, was not associated with AFF risk. Other risk factors included Asian ancestry (HR = 4.8 (3.6, 6.6)), short stature, overweight, and glucocorticoid use. Bisphosphonate discontinuation was associated with rapid decrease in AFF risk. Decreases in osteoporotic and hip fractures risk during 1-10 years of bisphosphonates far outweighed the increase AFF risk in Caucasians, but less so in Asians. In Caucasians, after 3 years 149 hip fractures were prevented with 2 AFFs associated compared to 91 and 8 in Asians. The evidence for several potential mechanisms is summarized with femoral geometry being the most likely to explain AFF risk differences between Asians and Caucasians. The results from this new study add to the evidence base for AFF risk factors and will help inform clinical decision-making for individual patients about initiation and duration of bisphosphonate therapy and drug holidays.

Sub-acute hyponatraemia more than chronic hyponatraemia is associated with serious falls and hip fractures

BACKGROUND

Falls and hip fractures among older people are associated with high morbidity and mortality. Hyponatraemia may be a risk for falls/hip fractures, but the effect of hyponatraemia duration is not well understood.

AIMS

To evaluate individuals with periods of sub-acute and chronic hyponatraemia on subsequent risk for serious falls and/or hip fractures.

METHODS

Retrospective cohort study in the period 1 January 1998 to 14 June 2016 within an integrated health system of individuals aged ≥55 years with ≥2 outpatient serum sodium measurements. Hyponatraemia was defined as sodium <135 mEq/L with sub-acute (<30 days) and chronic (≥30 days) analysed as a time-dependent exposure. Multivariable Cox proportional-hazards modelling was used to estimate hazard ratios (HR) for serious falls/hip fractures based on sodium category.

RESULTS

Among 1 062 647 individuals totalling 9 762 305 sodium measurements, 96 096 serious falls/hip fracture events occurred. Incidence (per-1000-person-years) of serious falls/hip fractures were 11.5, 27.9 and 19.8 for normonatraemia, sub-acute and chronic hyponatraemia. Any hyponatraemia duration compared to normonatraemia had a serious falls/hip fractures HR (95%CI) of 1.18 (1.15, 1.22), with sub-acute and chronic hyponatraemia having HR of 1.38 (1.33, 1.42) and 0.91 (0.87, 0.95), respectively. Examined separately, the serious falls HR was 1.37 (1.32, 1.42) and 0.92 (0.88, 0.96) in sub-acute and chronic hyponatraemia, respectively. Hip fracture HR were 1.52 (1.42, 1.62) and 1.00 (0.92, 1.08) for sub-acute and chronic hyponatraemia, respectively, compared to normonatraemia.

CONCLUSIONS

Our findings suggest that early/sub-acute hyponatraemia appears more vulnerable and associated with serious falls/hip fractures. Whether hyponatraemia is a marker of frailty or a modifiable risk factor for falls remains to be determined.

Bisphosphonate Treatment Beyond 5 Years and Hip Fracture Risk in Older Women

IMPORTANCE

Clinical trials have demonstrated the antifracture efficacy of bisphosphonate drugs for the first 3 to 5 years of therapy. However, the efficacy of continuing bisphosphonate for as long as 10 years is uncertain.

OBJECTIVE

To examine the association of discontinuing bisphosphonate at study entry, discontinuing at 2 years, and continuing for 5 additional years with the risk of hip fracture among women who had completed 5 years of bisphosphonate treatment at study entry.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included women who were members of Kaiser Permanente Northern and Southern California, 2 integrated health care delivery systems, and who had initiated oral bisphosphonate and completed 5 years of treatment by January 1, 2002, to September 30, 2014. Data analysis was conducted from January 2018 to August 2020.

EXPOSURE

Discontinuation of bisphosphonate at study entry (within a 6-month grace period), discontinuation at 2 years (within a 6-month grace period), and continuation for 5 additional years.

MAIN OUTCOMES AND MEASURES

The outcome was hip fracture determined by principal hospital discharge diagnoses. Demographic, clinical, and pharmacological data were ascertained from electronic health records.

RESULTS

Among 29 685 women (median [interquartile range] age, 71 [64-77] years; 17 778 [60%] non-Hispanic White individuals), 507 incident hip fractures were identified. Compared with bisphosphonate discontinuation at study entry, there were no differences in the cumulative incidence (ie, risk) of hip fracture if women remained on therapy for 2 additional years (5-year risk difference [RD], -2.2 per 1000 individuals; 95% CI, -20.3 to 15.9 per 1000 individuals) or if women continued therapy for 5 additional years (5-year RD, 3.8 per 1000 individuals; 95% CI, -7.4 to 15.0 per 1000 individuals). While 5-year differences in hip fracture risk comparing continuation for 5 additional years with discontinuation at 2 additional years were not statistically significant (5-year RD, 6.0 per 1000 individuals; 95% CI, -9.9 to 22.0 per 1000 individuals), interim hip fracture risk appeared lower if women discontinued after 2 additional years (3-year RD, 2.8 per 1000 individuals; 95% CI, 1.3 to 4.3 per 1000 individuals; 4-year RD, 9.3 per 1000 individuals; 95% CI, 6.3 to 12.3 per 1000 individuals) but not without a 6-month grace period to define discontinuation.

CONCLUSIONS AND RELEVANCE

In this study of women treated with bisphosphonate for 5 years, hip fracture risk did not differ if they discontinued treatment compared with continuing treatment for 5 additional years. If women continued for 2 additional years and then discontinued, their risk appeared lower than continuing for 5 additional years. Discontinuation at other times and fracture rates during intervening years should be further studied.

Does Knee Arthroscopy for Treatment of Meniscal Damage with Osteoarthritis Delay Knee Replacement Compared to Physical Therapy Alone?

BACKGROUD

To determine patient factors that lead to treatment of meniscal tears with osteoarthritis (OA) with knee arthroscopy (KA) or physical therapy only (PT-only); and to assess differences in clinical outcomes including the time to knee arthroplasty.

METHODS

Patients aged ≥ 45 years with OA at meniscal tear diagnosis were followed up from the date of surgery (KA) or first PT visit (PT-only) until partial/total knee replacement surgery, death, disenrollment, or end of study. Demographic and clinical characteristics were compared and used to derive propensity scores. A Cox proportional hazards model was used to estimate the risk of knee replacement surgery and greater healthcare utilization associated with KA vs. PT-only.

RESULTS

Among 7,026 patients (KA, 69%; PT-only, 31%), 27% had partial or total knee replacement surgery during follow-up. PT-only patients were older and more likely to be women and had more comorbidities. After accounting for differences between groups, the cumulative incidence of knee replacement was modestly but significantly higher for those who received KA than those who underwent PT-only (hazard ratio, 1.30; 95% confidence interval, 1.17-1.44; p < 0.001), although there was no significant difference in health service utilization, narcotic medication dispenses, or knee injections after initiating treatment.

CONCLUSIONS

For patients with meniscal damage complicated by OA, those who underwent KA were 30% more likely to have partial or total knee replacement surgery at any given time than those who had PT alone.

Atypical Femur Fracture Risk versus Fragility Fracture Prevention with Bisphosphonates

BACKGROUND

Bisphosphonates are effective in reducing hip and osteoporotic fractures. However, concerns about atypical femur fractures have contributed to substantially decreased bisphosphonate use, and the incidence of hip fractures may be increasing. Important uncertainties remain regarding the association between atypical femur fractures and bisphosphonates and other risk factors.

METHODS

We studied women 50 years of age or older who were receiving bisphosphonates and who were enrolled in the Kaiser Permanente Southern California health care system; women were followed from January 1, 2007, to November 30, 2017. The primary outcome was atypical femur fracture. Data on risk factors, including bisphosphonate use, were obtained from electronic health records. Fractures were radiographically adjudicated. Multivariable Cox models were used. The risk-benefit profile was modeled for 1 to 10 years of bisphosphonate use to compare associated atypical fractures with other fractures prevented.

RESULTS

Among 196,129 women, 277 atypical femur fractures occurred. After multivariable adjustment, the risk of atypical fracture increased with longer duration of bisphosphonate use: the hazard ratio as compared with less than 3 months increased from 8.86 (95% confidence interval [CI], 2.79 to 28.20) for 3 years to less than 5 years to 43.51 (95% CI, 13.70 to 138.15) for 8 years or more. Other risk factors included race (hazard ratio for Asians vs. Whites, 4.84; 95% CI, 3.57 to 6.56), height, weight, and glucocorticoid use. Bisphosphonate discontinuation was associated with a rapid decrease in the risk of atypical fracture. Decreases in the risk of osteoporotic and hip fractures during 1 to 10 years of bisphosphonate use far outweighed the increased risk of atypical fracture among Whites but less so among Asians. After 3 years, 149 hip fractures were prevented and 2 bisphosphonate-associated atypical fractures occurred in Whites, as compared with 91 and 8, respectively, in Asians.

CONCLUSIONS

The risk of atypical femur fracture increased with longer duration of bisphosphonate use and rapidly decreased after bisphosphonate discontinuation. Asians had a higher risk than Whites. The absolute risk of atypical femur fracture remained very low as compared with reductions in the risk of hip and other fractures with bisphosphonate treatment. (Funded by Kaiser Permanente and others.).

Determinants of Oral Bisphosphonate Use Beyond 5 Years

BACKGROUND

Few studies have examined factors that determine bisphosphonate (BP) continuation beyond 5 years in clinical practice.

OBJECTIVE

To investigate factors associated with BP continuation among women who completed 5 years of BP therapy.

METHODS

Women who received 5 consecutive years of oral BP treatment entered the cohort during 2002-2014 and were followed up to 5 additional years. Multivariable logistic regression was used to evaluate the association of demographic and clinical factors with adherent treatment continuation.

RESULTS

The cohort included 19,091 women with a median age of 72 years. Baseline and time-varying factors associated with increased odds of BP continuation after 5 years were (a) most recent bone mineral density (BMD) T-score -2 to -2.4 (OR = 1.31, 95% CI = 1.25-1.38), T-score -2.5 to -2.9 (OR = 1.48, 95% CI = 1.39-1.57), and T-score ≤ -3.0 (OR = 1.57, 95% CI = 1.47-1.68) versus T-scores above -2.0; (b) index date before 2008 (OR =1.35, 95% CI = 1.29-1.41); and (c) diabetes mellitus (OR = 1.08, 95% CI = 1.01-1.16). In contrast, factors associated with decreased odds of BP continuation were (a) recent hip (OR = 0.61, 95% CI = 0.52-0.71) or humerus (OR = 0.79, 95% CI = 0.66-0.94) fracture or fracture other than hip, wrist, spine, or humerus (OR = 0.90, 95% CI = 0.84-0.97); (b) Charlson Comorbidity Index score > 2 (OR = 0.91, 95% CI = 0.84-0.98); (c) history of rheumatoid arthritis (OR = 0.89, 95% CI = 0.80-0.99); (d) Hispanic (OR = 0.89, 95% CI=0.85-0.94) or Asian (OR = 0.90, 95% CI = 0.85-0.94) race/ethnicity; and (e) use of proton pump inhibitors (OR = 0.65, 95% CI = 0.59-0.71). Patient age and fracture before BP initiation were not associated with treatment continuation.

CONCLUSIONS

Clinical factors predicting continued BP treatment beyond 5 years include low BMD T-score, absence of recent fracture, and earlier era of treatment. Use of proton pump inhibitors was associated with lower likelihood of BP continuation. Other clinical and demographic factors were also noted to have variable effects on BP treatment continuation.

DISCLOSURES

This study was supported by a grant from the National Institute on Aging and National Institute of Arthritis, Musculoskeletal and Skin Diseases at the National Institutes of Health (NIH; R01AG047230, S1). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or Kaiser Permanente. Lo has received previous research funding from Amgen and Sanofi, unrelated to the current study. Adams has received previous research funding from Merck, Amgen, Otsuka, and Radius Health, unrelated to the current study. Ettinger has served as an expert witness for Teva Pharmaceuticals, unrelated to the current study. Ott previously attended a scientific advisory meeting for Amgen but declined the honorarium. The other authors have nothing to disclose. These data were presented at the 2018 Annual Meeting of the American Society of Bone and Mineral Research (ASBMR), September 28-October 1, 2018, Montreal, Quebec, Canada.

Using Pharmacy Data and Adherence to Define Long-Term Bisphosphonate Exposure in Women

BACKGROUND

Assigning drug exposure is a necessary first step in examining bisphosphonate (BP) treatment in observational studies using pharmacy data.

OBJECTIVE

To determine whether the choice of adherence level using the proportion of days covered (PDC) affected BP exposure assignment.

METHODS

10,381 female health plan members who initiated oral BP therapy between 2002 and 2010 and had received 5 consecutive years of treatment were identified and subsequently followed up to 5 additional years. In each 90-day interval of follow-up, a woman was considered "on treatment" if she received the drug for more than a predetermined PDC based on pharmacy days supply and "off treatment" if she received the drug for less than that PDC. Women who continued on therapy above the PDC threshold during follow-up were considered continuously on therapy. Women who were off treatment during the first 90-days of follow-up were classified as off therapy and were followed to determine if they remained continuously off treatment. This study evaluated the extent to which varying the PDC threshold (≥ 0.5, ≥ 0.6, and ≥ 0.7) affected the proportion of women classified as "continuously on" or "continuously off" BP during follow-up.

RESULTS

Under PDC thresholds of 0.5, 0.6, and 0.7, 48%, 43%, and 36% of women who remained on follow-up were categorized as continuously on treatment at year 2 of follow-up, and 18%, 14%, and 12% were categorized as continuously on treatment by the end of follow-up. Using these same PDC thresholds, 9%, 12%, and 15% of women were categorized as off therapy during the first quarter of follow-up and were highly likely to remain off therapy: 4%, 5%, and 5% were classified as continuously off therapy at year 2, and 4% of women were classified as such by the end of follow-up for all 3 thresholds.

CONCLUSIONS

A PDC of 0.6 was chosen as a practical threshold for drug adherence. Varying the PDC to 0.5 or 0.7 resulted in modest changes in the proportions of women considered continuously on BP therapy.

DISCLOSURES

This study was supported by a grant from the National Institute of Aging and National Institute of Arthritis, Musculoskeletal and Skin Diseases at the National Institutes of Health (R01AG047230, S1). Lo has received previous research funding from Amgen and Sanofi, outside of the current study. Chandra has received previous research funding from Amgen outside of the current study. Adams has received previous research funding from Merck, Amgen, Otsuka, and Radius Health, outside of the current study. Ott previously attended a scientific advisory meeting for Amgen but declined the honorarium. Ettinger previously served as an expert witness for Teva Pharmaceuticals.

Chronic hyponatremia and association with osteoporosis among a large racially/ethnically diverse population

Chronic hyponatremia may contribute to decreased bone density. We studied 341,003 men and women who underwent DXA testing and observed that individuals with chronic hyponatremia (sodium < 135 mEq/L) had an 11% greater likelihood of having osteoporosis. There was a dose-dependent effect with lower sodium and stronger association with osteoporosis.

INTRODUCTION

Chronic hyponatremia has been associated with both neurologic deficits and increased risk of gait abnormalities leading to falls and resultant bone fractures. Whether chronic hyponatremia contributes to decreased bone density is uncertain. We evaluated whether chronic, mild hyponatremia based on serial sodium measurements was associated with increased risk of osteoporosis within a large, ethnically diverse population.

METHODS

This is a retrospective cohort study between January 1, 1998 and December 31, 2014 within Kaiser Permanente Southern California, an integrated healthcare delivery system. Men and women were aged ≥ 55 years with ≥ 2 serum sodium measurements prior to dual-energy X-ray absorptiometry (DXA) testing. Time-weighted (TW) mean sodium values were calculated by using the proportion of time (weight) elapsed between sodium measurements and defined as < 135 mEq/L. Osteoporosis defined as any T-score value ≤ - 2.5 of lumbar spine, femoral neck, or hip.

RESULTS

Among 341,003 individuals with 3,330,903 sodium measurements, 11,539 (3.4%) had chronic hyponatremia and 151,505 (44.4%) had osteoporosis. Chronic hyponatremic individuals had an osteoporosis RR (95% CI) of 1.11 (1.09, 1.13) compared to those with normonatremia. A TW mean sodium increase of 3 mEq/L was associated with a lower risk of osteoporosis [adjusted RR (95% CI) 0.95 (0.93, 0.96)]. A similar association was observed when the arithmetic mean sodium value was used for comparison.

CONCLUSIONS

We observed a modest increase in risk for osteoporosis in people with chronic hyponatremia. There was also a graded association between higher TW mean sodium values and lower risk of osteoporosis. Our findings underscore the premise that chronic hyponatremia may lead to adverse physiological effects and responses which deserves better understanding.

End-organ effects of primary hyperparathyroidism: A population-based study

BACKGROUND

Patients with primary hyperparathyroidism are at risk for skeletal and renal end-organ damage.

METHODS

We studied patients with biochemically confirmed primary hyperparathyroidism from 1995-2014 and quantified the frequency of osteoporosis, nephrolithiasis, hypercalciuria, and decrease in renal function.

RESULTS

The cohort comprised 9,485 patients. In total, 3,303 (35%) had preexisting end-organ effects (osteoporosis, 24%; nephrolithiasis, 10%; hypercalciuria, 5%). Of 6,182 remaining patients, 1,769 (29%) exhibited progression to 1 or more end-organ effects over a median 3.7 years. Among patients with classic primary hyperparathyroidism (calcium and parathyroid hormone increased), progression was unrelated to the degree of hypercalcemia (calcium >11.5 mg/dL, hazard ratio 1.03, 95% confidence interval 0.85-1.25; 11.1-11.5 mg/dL, HR 1.07, 95% confidence interval 0.93-1.23; 10.5-11.0 mg/dL = reference). Patients with nonclassic primary hyperparathyroidism (calcium increased, parathyroid hormone 40-65 pg/mL) had a lesser risk of progression (calcium >11.5 mg/dL, hazard ratio 0.68, 95% confidence interval 0.50-0.94; 11.1-11.5 mg/dL, hazard ratio 0.68, 95% confidence interval 0.56-0.82; 10.5-11.0 mg/dL, hazard ratio 0.66, 95% confidence interval 0.59-0.74). End-organ damage developed before or within 5 years of diagnosis for 62% of patients.

CONCLUSION

End-organ manifestations of primary hyperparathyroidism develop before biochemical diagnosis or within 5 years in most patients. End-organ damage occurred more frequently in patients with classic primary hyperparathyroidism versus nonclassic primary hyperparathyroidism, regardless of severity of hypercalcemia.

Osteoporosis and Hip Fracture Risk From Routine Computed Tomography Scans: The Fracture, Osteoporosis, and CT Utilization Study (FOCUS)

Methods now exist for analyzing previously taken clinical computed tomography (CT) scans to measure a dual-energy X-ray absorptiometry (DXA)-equivalent bone mineral density (BMD) at the hip and a finite element analysis-derived femoral strength. We assessed the efficacy of this "biomechanical CT" (BCT) approach for identifying patients at high risk of incident hip fracture in a large clinical setting. Using a case-cohort design sampled from 111,694 women and men aged 65 or older who had a prior hip CT scan, a DXA within 3 years of the CT, and no prior hip fracture, we compared those with subsequent hip fracture (n = 1959) with randomly selected sex-stratified controls (n = 1979) and analyzed their CT scans blinded to all other data. We found that the age-, race-, and body mass index (BMI)-adjusted hazard ratio (HR; per standard deviation) for femoral strength was significant before (women: HR = 2.8, 95% confidence interval [CI] 2.2-3.5; men: 2.8, 2.1-3.7) and after adjusting also for the (lowest) hip BMD T-score by BCT (women: 2.1, 1.4-3.2; men: 2.7, 1.6-4.6). The hazard ratio for the hip BMD T-score was similar between BCT and DXA for both sexes (women: 2.1, 1.8-2.5 BCT versus 2.1, 1.7-2.5 DXA; men: 2.8, 2.1-3.8 BCT versus 2.5, 2.0-3.2 DXA) and was higher than for the (lowest) spine/hip BMD T-score by DXA (women: 1.6, 1.4-1.9; men: 2.1, 1.6-2.7). Compared with the latter as a clinical-practice reference and using both femoral strength and the hip BMD T-score from BCT, sensitivity for predicting hip fracture was higher for BCT (women: 0.66 versus 0.59; men: 0.56 versus 0.48), with comparable respective specificity (women: 0.66 versus 0.67; men: 0.76 versus 0.78). We conclude that BCT analysis of previously acquired routine abdominal or pelvic CT scans is at least as effective as DXA testing for identifying patients at high risk of hip fracture. © 2018 American Society for Bone and Mineral Research.

Bisphosphonate Drug Holiday and Fracture Risk: A Population-Based Cohort Study

Holidays from bisphosphonates (BPs) may help to prevent rare adverse events such as atypical femoral fractures, but may be appropriate only if risk of osteoporosis-related fractures does not increase. Our objective was to compare the incidence of osteoporosis-related fractures among women who had a BP holiday to those who continued to use BPs. This retrospective cohort study, conducted within four Kaiser Permanente integrated health system regions, included 39,502 women aged ≥45 years with ≥3 years exposure to BP. Participants with a BP holiday (≥12 months with no use) were compared to persistent (use with ≥50% adherence) and nonpersistent (use with <50% adherence) users for incident osteoporosis-related fractures. The BP holiday (n = 11,497), nonpersistent user (n = 10,882), and persistent user groups (n = 17,123) were observed for 156,657 person-years. A total of 5199 osteoporosis-related fractures (including 1515 hip fractures and 2147 vertebral fractures) were observed. Compared to the persistent use group, there was a slight difference in overall osteoporosis-related fracture risk (HR 0.92; 95% CI, 0.84 to 0.99)and no difference in hip fracture risk (HR 0.95; 95% CI, 0.83 to 1.10) for the BP holiday group. A slight reduction in risk of vertebral fracture was observed (HR 0.83; 95% CI, 0.74 to 0.95). Compared to the nonpersistent user group, the BP holiday group was at decreased risk for osteoporosis-related fractures (HR 0.71; 95% CI, 0.65 to 0.79), vertebral fractures (HR 0.68; 95% CI, 0.59 to 0.78), and hip fractures (HR 0.59; 95% CI, 0.50 to 0.70). Women who undertake a BP holiday from BP of ≥12 months duration for any reason after ≥3 years of BP use do not appear to be at greater risk of osteoporosis-related fragility fracture, hip, or vertebral fractures compared to ongoing BP users. In our cohort, BP holiday remains a viable strategy for balancing the benefits and potential harms associated with long-term BP use. © 2018 American Society for Bone and Mineral Research.

Trends in bisphosphonate initiation within an integrated healthcare delivery system

In the setting of changing temporal trends in the management of osteoporosis, we examined how select characteristics of new oral bisphosphonate (BP) initiators changed over time among 94,073 women within a large, integrated healthcare organization during the period 2004 to 2012. In the earlier era (2004-2007), approximately half of women younger than 65 years initiating BP therapy (47%-54%) had osteoporosis by bone mineral density (BMD) criteria, but this proportion increased sharply in the later era (2008-2012), with 55% to 81% having osteoporosis. This trend was not evident in older women (≥65 years). The proportion of younger women with prior fracture increased from 15% in 2008 to 32% in 2012, after remaining relatively stable (10%-15%) during the earlier era. Again, this trend was not observed among older women. Thus, among women younger than 65 years, we observed a marked temporal shift in initiation of BP treatment toward women at high risk (including those with prior fracture and those with osteoporosis by BMD testing) and away from those at lower risk (such as those with osteopenia and/or no prior fracture).

Skeletal effects of failed parathyroidectomy

BACKGROUND

Parathyroidectomy improves bone mineral density and decreases risk for fracture in patients with primary hyperparathyroidism. The aim of this study was to determine skeletal consequences of failed parathyroidectomy.

METHODS

A retrospective, cohort study of patients with biochemically confirmed primary hyperparathyroidism within a vertically integrated health system was performed (1995-2014). Failed parathyroidectomy was defined by hypercalcemia within 6 months of initial parathyroidectomy. Time-varying Cox regression was used to estimate the risk for any fracture and hip fracture in 3 comparison groups: observation, successful parathyroidectomy, and failed parathyroidectomy. Bone mineral density changes also were compared.

RESULTS

The cohort included 7,169 patients, of whom 5,802 (81%) were observed, 1,228 underwent successful parathyroidectomy (17%), and 137 underwent failed parathyroidectomy (2%). The adjusted risk for any fracture (hazard ratio, 1.28; 95% confidence interval, 0.85-1.92) and hip fracture (hazard ratio, 1.63; 95% CI, 0.77-3.45) associated with failed parathyroidectomy was similar to that associated with observation. Successful parathyroidectomy was associated with a decrease in any fracture (hazard ratio, 0.68; 95% confidence interval, 0.57-0.82) and hip fracture (hazard ratio, 0.43; 95% confidence interval, 0.27-0.68) compared with observation. Bone mineral density changes in the failed parathyroidectomy group paralleled those associated with observation.

CONCLUSION

Failed parathyroidectomy is associated with a high risk for fracture similar to that seen with observation.

Predicting Adherence and Persistence with Oral Bisphosphonate Therapy in an Integrated Health Care Delivery System

BACKGROUND

Examining drug exposure is essential to pharmacovigilance, especially for bisphosphonate (BP) therapy.

OBJECTIVE

To examine differences in 4 measures of oral BP exposure: treatment discontinuation, adherence, persistence, and nonpersistence.

METHODS

Among women aged ≥ 50 years who initiated oral BP therapy during 2002-2007 with at least 3 years of health plan membership follow-up, discontinuation was defined by evidence of no further treatment during the study observation period. Among those with at least 2 filled BP prescriptions during the study period, adherence was calculated for each year of follow-up using the (modified) proportion of days covered (mPDC) metric that allows for stockpiling of prescription/refills overlap ≤ 30 days supply. Persistence was quantified by treatment duration, allowing a gap of up to 60 days between prescription/refill days covered. Nonpersistence was quantified by the periods without drugs outside this allowable gap. Multivariable logistic regression was used to compare age and race groups and the relationships of early adherence (adherence during the first year) with subsequent adherence.

RESULTS

Among 48,390 women initiating oral BP therapy and followed for 3 years, 26.7% discontinued in year 1, and 14.7% of the remaining 35,456 women discontinued in year 2. Discontinuation rates were slightly higher (29.4%, P < 0.001) for women aged ≥ 75 years and somewhat lower (21.1%, P < 0.001) for Asian women. During the first year, 60.4% of the women achieved an mPDC of ≥ 75%, with demographic differences in adherence similar to that seen for treatment discontinuation. Over the 3 years, the median mPDC levels for BP therapy were 86%, 84%, and 85% in years 1, 2, and 3, respectively, for those receiving treatment. Cumulative persistence was 2.3 years (median, IQR = 1.0-3.0) overall and slightly greater for Asian versus white women and lower for older women. There were 18,174 (42.9%) women with at least 1 period of nonpersistence during 3 years follow-up in excess of the 60-day allowable gap between prescription/refills (median cumulative nonpersistence = 0.65, IQR = 0.30-1.25 years). Women with mPDC ≥ 75% during the first year had a 12-fold and 6-fold increased odds of mPDC ≥ 75% during year 2 and year 3, respectively.

CONCLUSIONS

BP discontinuation rates are highest for women during the first year. Among those continuing treatment in subsequent years, adherence rates were relatively stable. Persistence and adherence varied slightly by age and was somewhat higher in Asians, contributing to differences in cumulative BP exposure. We also found evidence that optimal adherence in the first year was highly predictive of optimal adherence in the subsequent 1-2 years. Hence, subgroups of patients receiving oral BP drugs may require different levels of support and monitoring to maximize treatment benefit, especially based on early patterns of use.

DISCLOSURES

This study was supported by grants from the Kaiser Permanente Northern California Community Benefit Program and the National Institutes of Health, 1R01AG047230-01A1. The opinions expressed in this publication are solely the responsibility of the authors and do not represent the official views of Kaiser Permanente or the National Institutes of Health. Hui, Yi, and Chandra have received past research funding from Amgen not related to the current study. Adams has received research funding from Amgen, Merck, and Otsuka not related to the current study. Niu has received research funding from Bristol-Myers Squibb not related to the current study. Ettinger has received past legal fees in litigation involving Fosamax. Lo has received past research funding from Amgen and current research funding from Sanofi not related to the current study. The data from this study were presented at the Academy of Managed Care Pharmacy Annual Meeting; April 19-22, 2016; San Francisco, California. Study concept and design were contributed primarily by Hui and Lo, along with Adams, Niu, Yi, and Ettinger. Hui took the lead in data collection, along with Chandra, and data interpretation was performed by Niu, Yi, and Lo, along with the other authors. The manuscript was written by Hui, Adams, and Lo, along with Niu, Yi, and Ettinger, and revised by Ettinger, Hui, Lo, and Niu, along with the other authors.

Sensitivity and specificity of radiographic characteristics in atypical femoral fractures

Using the American Society for Bone and Mineral Research Task Force case definition for atypical femoral fractures, sensitivity and specificity of radiographic fracture characteristics were calculated. Fracture pattern was the most sensitive and specific characteristic. This suggests that some characteristics should be weighted more heavily when identifying these fractures.

INTRODUCTION

To estimate the sensitivity and specificity of each radiographic criterion in the 2013 ASBMR atypical femoral fracture (AFF) case definition for distinguishing AFF from other subtrochanteric/diaphyseal fractures (non-AFF) among women enrolled in a large integrated health care organization.

METHODS

Radiographs from 55 physician-confirmed AFFs and a sample of 39 non-AFFs were reviewed by four independent expert reviewers representing four medical specialties. One image per fracture was selected for review. Using a standardized data collection tool, based on the 2013 AFF case definition, reviewers indicated the presence or absence of the following characteristics viewable on radiograph: fracture pattern, comminution, periosteal and/or endosteal thickening, and cortical thickening. Sensitivity and specificity for each characteristic was calculated for each reviewer and summarized across reviewers with the mean and range. Agreement across reviewers was quantified using Fleiss's kappa (FK) statistic.

RESULTS

The most sensitive factors distinguishing AFF from non-AFF were lateral cortex transverse fracture pattern (mean 93.6 %, range 85.5-98.2 %), medial cortex transverse or oblique fracture pattern (mean 84.1 %, range 72.7-98.2 %), and minimal/non-comminution (mean 93.2 %, range 89.1-98.2 %). Specificity was the greatest for lateral cortex transverse fracture pattern (mean 95.5 %, range 92.3-97.4 %). Agreement across reviewers was the highest for lateral cortex transverse fracture pattern (FK 0.83) and incomplete fracture through the lateral cortex only (FK 0.80).

CONCLUSION

Lateral cortex transverse fracture pattern was the most sensitive and specific characteristic and the most highly agreed upon across reviewers. Other characteristics were less readily agreed upon across reviewers. Measurement of discrete combinations of individual characteristics may enhance sensitivity and/or specificity.

The Relationship of Parathyroidectomy and Bisphosphonates With Fracture Risk in Primary Hyperparathyroidism: An Observational Study

BACKGROUND

The comparative effectiveness of surgical and medical treatments on fracture risk in primary hyperparathyroidism (PHPT) is unknown.

OBJECTIVE

To measure the relationship of parathyroidectomy and bisphosphonates with skeletal outcomes in patients with PHPT.

DESIGN

Retrospective cohort study.

SETTING

An integrated health care delivery system.

PARTICIPANTS

All enrollees with biochemically confirmed PHPT from 1995 to 2010.

MEASUREMENTS

Bone mineral density (BMD) changes and fracture rate.

RESULTS

In 2013 patients with serial bone density examinations, total hip BMD increased transiently in women with parathyroidectomy (4.2% at <2 years) and bisphosphonates (3.6% at <2 years) and declined progressively in both women and men without these treatments (-6.6% and -7.6%, respectively, at >8 years). In 6272 patients followed for fracture, the absolute risk for hip fracture at 10 years was 20.4 events per 1000 patients who had parathyroidectomy and 85.5 events per 1000 patients treated with bisphosphonates compared with 55.9 events per 1000 patients without these treatments. The risk for any fracture at 10 years was 156.8 events per 1000 patients who had parathyroidectomy and 302.5 events per 1000 patients treated with bisphosphonates compared with 206.1 events per 1000 patients without these treatments. In analyses stratified by baseline BMD status, parathyroidectomy was associated with reduced fracture risk in both osteopenic and osteoporotic patients, whereas bisphosphonates were associated with increased fracture risk in these patients. Parathyroidectomy was associated with fracture risk reduction in patients regardless of whether they satisfied criteria from consensus guidelines for surgery.

LIMITATION

Retrospective study design and nonrandom treatment assignment.

CONCLUSION

Parathyroidectomy was associated with reduced fracture risk, and bisphosphonate treatment was not superior to observation.

PRIMARY FUNDING SOURCE

National Institute on Aging.

The effect of osteoporosis management on proximal humeral fracture

HYPOTHESIS AND BACKGROUND

Proximal humeral fractures comprise 10% of fractures in the Medicare population. The effect, if any, of treating osteoporosis to prevent these fractures has not been determined. The primary objective is to determine the effectiveness of a systematic osteoporosis screening and treatment program on the hazard of developing a fracture over the treatment period. The secondary aim is to determine demographic risk factors.

METHODS

This is a retrospective cohort study in a health care organization serving 3.3 million members. Individuals selected for dual-energy x-ray absorptiometry screening were (1) women aged 65 years or older; (2) men aged 70 years or older; and (3) individuals aged 50 years or older who have a history of fragility fracture, use glucocorticoids, have a parental history of hip fracture, have rheumatoid arthritis, use alcohol at a high rate, or are cigarette smokers. Treatment consisted primarily of pharmacologic intervention with bisphosphonates.

RESULTS

Individuals diagnosed with osteoporosis had a hazard ratio of 7.43 for sustaining a fracture over the study period. Patients screened with dual-energy x-ray absorptiometry had a hazard ratio of 0.17 whereas those treated medically had a hazard ratio of 0.55 versus untreated controls. Risk factors that significantly increased the risk of a fracture developing included age, female gender, white race, diabetes mellitus, and history of a distal radius fracture.

DISCUSSION AND CONCLUSION

Over the study period, screening and treatment for osteoporosis significantly decreased the hazard ratio for proximal humeral fracture. This information broadens the impact of such programs because current best practices are primarily based on prevention of spine and hip fractures.

Associations between childhood obesity and upper and lower extremity injuries

OBJECTIVES

To estimate the overall and age-specific associations between obesity and extremity musculoskeletal injuries and pain in children.

METHODS

This cross-sectional study used information from electronic medical records of 913178 patients aged 2-19 years enrolled in an integrated health plan in the period 2007-2009. Children were classified as underweight, normal weight, overweight, or moderately/extremely obese and, using multivariable logistic regression methods, the associations between weight class and diagnosis of upper or lower extremity fractures, sprains, dislocations and pain were calculated.

RESULTS

Overweight (OR 1.18, 95% CI 1.15 to 1.20), moderately obese (OR 1.24, 95% CI 1.20 to 1.27) and extremely obese (OR 1.34, 95% CI 1.30 to 1.39) children had statistically significantly higher odds of lower extremity injuries/pain compared to normal weight, adjusted for sex, age, race/ethnicity and insurance status. Age-stratified analyses yielded similar results. No consistent association was observed between body mass index and injuries/pain of the upper extremities.

CONCLUSIONS

Greater body mass index is associated with increased odds of lower extremity injuries and pain issues. Because the benefits of physical activity may still outweigh the risk of injury, attention should be paid to injury prevention strategies for these children at greater risk for lower extremity injuries.

Surgical outcomes of total knee replacement according to diabetes status and glycemic control, 2001 to 2009

BACKGROUND

Poor glycemic control in patients with diabetes may be associated with adverse surgical outcomes. We sought to determine the association of diabetes status and preoperative glycemic control with several surgical outcomes, including revision arthroplasty and deep infection.

METHODS

We conducted a retrospective cohort study in five regions of a large integrated health-care organization. Eligible subjects, identified from the Kaiser Permanente Total Joint Replacement Registry, underwent an elective first primary total knee arthroplasty during 2001 through 2009. Data on demographics, diabetes status, preoperative hemoglobin A1c (HbA1c) level, and comorbid conditions were obtained from electronic medical records. Subjects were classified as nondiabetic, diabetic with HbA1c < 7% (controlled diabetes), or diabetic with HbA1c ≥ 7% (uncontrolled diabetes). Outcomes were deep venous thrombosis or pulmonary embolism within ninety days after surgery and revision surgery, deep infection, incident myocardial infarction, and all-cause rehospitalization within one year after surgery. Patients without diabetes were the reference group in all analyses. All models were adjusted for age, sex, body mass index, and Charlson Comorbidity Index.

RESULTS

Of 40,491 patients who underwent total knee arthroplasty, 7567 (18.7%) had diabetes, 464 (1.1%) underwent revision arthroplasty, and 287 (0.7%) developed a deep infection. Compared with the patients without diabetes, no association between controlled diabetes (HbA1c < 7%) and the risk of revision (odds ratio [OR], 1.32; 95% confidence interval [CI], 0.99 to 1.76), risk of deep infection (OR, 1.31; 95% CI, 0.92 to 1.86), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.84; 95% CI, 0.60 to 1.17) was observed. Similarly, compared with patients without diabetes, no association between uncontrolled diabetes (HbA1c ≥ 7%) and the risk of revision (OR, 1.03; 95% CI, 0.68 to 1.54), risk of deep infection (OR, 0.55; 95% CI 0.29 to 1.06), or risk of deep venous thrombosis or pulmonary embolism (OR, 0.70; 95% CI, 0.43 to 1.13) was observed.

CONCLUSIONS

No significantly increased risk of revision arthroplasty, deep infection, or deep venous thrombosis was found in patients with diabetes (as defined on the basis of preoperative HbA1c levels and other criteria) compared with patients without diabetes in the study population of patients who underwent elective total knee arthroplasty.

Incidence and prevalence of primary hyperparathyroidism in a racially mixed population

CONTEXT

The epidemiology of primary hyperparathyroidism (PHPT) has generally been studied in Caucasian populations.

OBJECTIVE

The aim was to examine the incidence and prevalence of PHPT within a racially mixed population.

DESIGN

A descriptive epidemiologic study was performed.

PATIENTS/SETTING

The study population included 3.5 million enrollees within Kaiser Permanente Southern California.

METHODS

All patients with at least one elevated serum calcium level (>10.5 mg/dL, 2.6 mmol/L) between 1995 and 2010 were included. Cases of PHPT were identified by electronic query of laboratory values using biochemical criteria, after exclusion of secondary or renal and tertiary hyperparathyroidism cases. The incidence and prevalence rates of PHPT were calculated according to sex, race, age group by decade, and year.

RESULTS

Initial case finding identified 15,234 patients with chronic hypercalcemia, 13,327 (87%) of which had PHPT as defined by elevated or inappropriately normal parathyroid hormone levels. The incidence of PHPT fluctuated from 34 to 120 per 100,000 person-years (mean 66) among women, and from 13 to 36 (mean 25) among men. With advancing age, incidence increased and sex differences became pronounced (incidence 12-24 per 100,000 for both sexes younger than 50 y; 80 and 36 per 100,000 for women and men aged 50-59 y, respectively; and 196 and 95 for women and men aged 70-79 y, respectively). The incidence of PHPT was highest among blacks (92 women; 46 men, P < .0001), followed by whites (81 women; 29 men), with rates for Asians (52 women, 28 men), Hispanics (49 women, 17 men), and other races (25 women, 6 men) being lower than that for whites (P < .0001). The prevalence of PHPT tripled during the study period, increasing from 76 to 233 per 100,000 women and from 30 to 85 per 100 000 men. Racial differences in prevalence mirrored those found in incidence.

CONCLUSIONS

PHPT is the predominant cause of hypercalcemia and is increasingly prevalent. Substantial differences are found in the incidence and prevalence of PHPT between races.

Ten-year hip fracture incidence rate trends in a large California population, 1997-2006

Hip fractures are a large public health problem with significant negative impact on an individual's overall health and survival. But while the total numbers of persons affected by hip fractures may be anticipated to increase, incidence rates appear to be declining.

INTRODUCTION

To describe annual hip fracture incidence rate trends in an integrated health-care organization over 1997-2006, during which a proactive bone health program was initiated program-wide and other secular trends occurred in the population.

METHODS

For this ecologic trend study, we identified all men and women ≥45 years old as of January 1 of each year. Incident fractures for each year were identified using ICD-9 diagnosis codes 820-820.9, excluding all subjects who had fractures in prior years. Annual person-time at risk for hip fracture was determined from enrollment data. Sex- and age-specific and adjusted annual incidence rates were calculated.

RESULTS

The overall annual hip fracture incidence rate for men declined from 1.52/1,000 person-years in 1997 to 1.29/1,000 person-years in 2006, a 15.3% (95% confidence interval [CI]=6.2-24.5) decrease. For women, incidence declined from 2.65/1,000 person-years in 1997 to 2.24/1,000 person-years in 2006, a 15.3% (95% CI=8.7-21.9) decrease. Among subjects aged 85 years or older, incidence rates for men declined from 27.0/1,000 to 18.9/1,000 person-years, and for women they declined from 32.7/1,000 to 27.1/1,000 person-years.

CONCLUSION

Hip fracture incidence has been declining in all age groups over the past 10 years. While many factors may contribute to this decline, the results are consistent with a potential benefit of the active bone health intervention.

Incidence of atypical nontraumatic diaphyseal fractures of the femur

Bisphosphonates reduce the rate of osteoporotic fractures in clinical trials and community practice. "Atypical" nontraumatic fractures of the diaphyseal (subtrochanteric or shaft) part of the femur have been observed in patients taking bisphosphonates. We calculated the incidence of these fractures within a defined population and examined the incidence rates according to duration of bisphosphonate use. We identified all femur fractures from January 1, 2007 until December 31, 2011 in 1,835,116 patients older than 45 years who were enrolled in the Healthy Bones Program at Kaiser Southern California, an integrated health care provider. Potential atypical fractures were identified by diagnostic or procedure codes and adjudicated by examination of radiographs. Bisphosphonate exposure was derived from internal pharmacy records. The results showed that 142 patients had atypical fractures; of these, 128 had bisphosphonate exposure. There was no significant correlation between duration of use (5.5 ± 3.4 years) and age (69.3 ± 8.6 years) or bone density (T-score -2.1 ± 1.0). There were 188,814 patients who had used bisphosphonates. The age-adjusted incidence rates for an atypical fracture were 1.78/100,000/year (95% confidence interval [CI], 1.5-2.0) with exposure from 0.1 to 1.9 years, and increased to 113.1/100,000/year (95% CI, 69.3-156.8) with exposure from 8 to 9.9 years. We conclude that the incidence of atypical fractures of the femur increases with longer duration of bisphosphonate use. The rate is much lower than the expected rate of devastating hip fractures in elderly osteoporotic patients. Patients at risk for osteoporotic fractures should not be discouraged from initiating bisphosphonates, because clinical trials have documented that these medicines can substantially reduce the incidence of typical hip fractures. The increased risk of atypical fractures should be taken into consideration when continuing bisphosphonates beyond 5 years.

How accurately can emergency department providers estimate patient satisfaction?

Introduction

Patient satisfaction is an important measure of emergency department (ED) quality of care. Little is known about providers' ability to estimate patient satisfaction. We aimed to measure providers' ability to assess patient satisfaction and hypothesized that providers could accurately estimate overall patient satisfaction.

Methods

We surveyed ED patients regarding satisfaction with their care. Treating providers completed analogous surveys, estimating patients' responses. Sexual assault victims and non-English-speaking or severely ill patients were excluded. Satisfaction responses were categorized as “satisfied” or “not satisfied.” Patient satisfaction scores were considered the “gold standard,” and providers' perceptions of the patient satisfaction were considered tests. Measures of diagnostic accuracy, such as positive predictive value (PPV) and sensitivity, were used to assess how accurately the provider could estimate his or her patient's satisfaction.

Results

Here, 242/457 eligible patients (53%) completed the survey; 227 providers (94%) completed a corresponding survey. Subject-reported overall satisfaction was 96.6%, compared with a provider-estimated rate of 94.4%. The sensitivity and PPV of the provider's estimate of the patient's satisfaction were 95.2 (95% confidence interval [CI] 91.4, 97.7) and 97.5 (95% CI 94.4, 99.2), respectively, for overall patient satisfaction. The PPV was similar for clarity of communication. The PPV was 78.9 for perceived length of ED stay (99% CI 70.8, 85.6) and 82.6 for quality of pain control (95% CI 68.6, 92.3). Accuracy of attending and resident estimates of patient satisfaction did not differ significantly. The agreement between patient-reported and provider-estimated patient satisfaction was not associated with age, gender, patient disposition, or ED divert status.

Conclusion

Providers are able to assess overall patient satisfaction and clarity of communication with a high accuracy. Physician estimates of pain control and perceived length of stay have a moderate accuracy.

BMI and fracture risk in older men: the osteoporotic fractures in men study (MrOS)

Low body mass index (BMI) is a risk factor for fracture, but little is known about the association between high BMI and fracture risk. We evaluated the association between BMI and fracture in the Osteoporotic Fractures in Men Study (MrOS), a cohort of 5995 US men 65 years of age and older. Standardized measures included weight, height, and hip bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA); medical history; lifestyle; and physical performance. Only 6 men (0.1%) were underweight (<18.5 kg/m(2)); therefore, men in this category were excluded. Also, 27% of men had normal BMI (18.5 to 24.9 kg/m(2)), 52% were overweight (25 to 29.9 kg/m(2)), 18% were obese I (30 to 34.9 kg/m(2)), and 3% were obese II (35 to 39.9 kg/m(2)). Overall, nonspine fracture incidence was 16.1 per 1000 person-years, and hip fracture incidence was 3.1 per 1000 person-years. In age-, race-, and BMD-adjusted models, compared with normal weight, the hazard ratio (HR) for nonspine fracture was 1.04 [95% confidence interval (CI) 0.87-1.25] for overweight, 1.29 (95% CI 1.00-1.67) for obese I, and 1.94 (95% CI 1.25-3.02) for obese II. Associations were weaker and not statistically significant after adjustment for mobility limitations and walking pace (HR = 1.02, 95% CI 0.84-1.23, for overweight; HR = 1.12, 95% CI 0.86-1.46, for obese I, and HR = 1.44, 95% CI 0.90-2.28, for obese II). Obesity is common among older men, and when BMD is held constant, it is associated with an increased risk of fracture. This association is at least partially explained by worse physical function in obese men.

The optimum follow-up period for assessing mortality outcomes in injured older adults

OBJECTIVES

To compare mortality rates of hospitalized injured aged 67 and older across commonly used follow-up periods (e.g., in-hospital, 30-day, 1-year) and to determine the postinjury time after which mortality rates stabilize.

DESIGN

Retrospective analysis of Medicare claims.

SETTING

Oregon and Washington Medicare patients.

PARTICIPANTS

Patients admitted to 171 Oregon and Washington facilities during 2001/02 with injuries identified according to International Classification of Diseases, Ninth Revision, code and followed for 1 year.

MEASUREMENTS

The primary outcome was in-hospital mortality and mortality at 30, 60, 90, 180, and 365 days. Kaplan-Meier survival curves and daily postadmission mortality rates were also evaluated. The rate of change (slope) of the survival curves and daily mortality rates were analyzed to select the point after which mortality rates were no longer decreasing.

RESULTS

There were 32,135 injured older adults hospitalized over the 2-year period, with a median age of 82 (interquartile range 77-88). Cumulative in-hospital mortality and at 30, 60, 90, 180, and 365 days was 4.1%, 9.7%, 13.6%, 16.1%, 21.3%, and 28.4%, respectively. Mortality rates stabilized by 6 months after injury, with 89% of the change occurring within 60 days. Although serious injuries, medical comorbidities, and preinjury nursing facility residence were all associated with higher mortality, they did not affect the pattern of mortality after injury.

CONCLUSION

In-hospital mortality is much lower than postdischarge mortality in injured older adults, with a substantial portion of persons dying shortly after discharge from the hospital. Mortality appears to stabilize by 6 months after injury, although 60-day postadmission follow-up captures most of the excess daily mortality rate.

Injury hospitalization as a marker for emergency medical services use in elderly patients

BACKGROUND

The elderly utilize emergency medical services (EMS) at a higher rate than younger patients, yet little is known about the influence of injury on subsequent EMS utilization and costs.

OBJECTIVE

To assess injury hospitalization as a potential marker for subsequent EMS utilization and costs by Medicare patients.

METHODS

This observational study analyzed a retrospective cohort of all Medicare patients (> or = 67 years old) with an International Classification of Diseases, Ninth Revision (ICD-9) injury diagnosis admitted to 125 Oregon and Washington hospitals during 2001 and 2002 who survived to hospital discharge. The numbers of EMS transports and the total EMS costs were compared one year before and one year following the index hospitalization.

RESULTS

There were 30,655 injured elders in our cohort. Their median ICD-9-based injury severity score was 0.97, with 4.1% meeting a definition of serious injury and 37% having hip fractures. The mean (range) numbers of EMS transports before and after the injury were 0.5 (0-45) and 0.9 (0-56), for an unadjusted incidence rate ratio (IRR) of 1.7 (95% confidence interval [CI] 1.7-1.8). The increase in EMS utilization following an injury hospitalization was even greater after adjusting for risk period and other model predictors (IRR 2.4, 95% CI 2.3-2.5). Annual mean EMS costs rose 74% following the injury hospitalization, from $211 to $367 per person. The greatest increase was in nonemergent EMS use, accounting for 67% of the increase in the number of uses. Institutionalization in a skilled nursing or rehabilitation facility either before or after injury was strongly associated with the need for EMS care.

CONCLUSION

An injury hospitalization in the elderly serves as a sentinel marker for an abrupt increase in EMS utilization and costs, even after accounting for confounders.

Efficacy of a brief intervention to improve emergency physicians' smoking cessation counseling skills, knowledge, and attitudes

The objective of this study was to test whether a brief educational/administrative intervention could increase tobacco counseling by emergency physicians (EPs). Pre-/post-study at eight emergency departments (EDs) with residency programs were carried out. EPs received a 1-hour lecture on the health effects of smoking and strategies to counsel patients. After the lecture, cards promoting a national smokers' quitline were placed in EDs, to be distributed by providers. Providers completed pre-/ post-intervention questionnaires. Patients were interviewed pre-/post-intervention to assess provider behavior. Two hundred eighty-seven EPs were enrolled. Post-intervention, providers were more likely to consider tobacco counseling part of their role, and felt more confident in counseling. Data from 1168 patient interviews and chart reviews showed that, post-intervention, providers were more likely to ask patients about smoking, make a referral, and document smoking counseling. Post-intervention, 30% of smokers were given a Quitline referral card. An educational intervention improved ED-based tobacco interventions. Controlled trials are needed to establish these results' durability.

Altered pre-pulse inhibition in adult rats treated neonatally with domoic acid

Altered functioning of the glutamate system during critical periods of development is believed to play a role in various neurodevelopmental disorders, such as schizophrenia. Prepulse inhibition (PPI) of the acoustic startle response is deficient in people with schizophrenia. This study investigated the theory that neonatal treatment with domoic acid (DOM), a glutamate agonist, leads to deficient PPI. Results indicate that neonatal treatment with DOM leads to lowered PPI in adult males and an increased startle response in adult females.

Search Is a Time-Critical Event: When Search and Rescue Missions May Become Futile

OBJECTIVES

The purpose of this study was to derive and validate a rule for duration of search (ie, search time) that maximizes survivors and after which a search and rescue (SAR) mission may be considered for termination.

METHODS

This was a retrospective cohort study of all SAR missions initiated in Oregon over a 7-year period, which were documented in a population-based administrative database. The following types of search missions were excluded from analysis: redundant reports of a single search; lost helicopters and airplanes; support of organized events; law-enforcement searches; searches for persons actively avoiding rescue; body recovery missions; and cases without outcome information. The cohort was divided into a derivation cohort (searches from 1997-2000) and a validation cohort (2001-2003). The primary outcome was survival. Variables considered in the model included age, gender, minimum and maximum daily temperatures, precipitation, search time, and whether the search involved an air or water incident. Missing data were handled using multiple imputation. Classification and regression tree (CART) methods were used to derive the model.

RESULTS

The derivation cohort included 1040 searches involving 1509 victims, 70 (4.6%) of whom died. The validation cohort included 1262 searches involving 1778 victims; 115 (6.5%) died. Search time was the only variable retained in the final model, with a cut-point of 51 hours. The derivation model was 98.9% sensitive; the same model run using the validation cohort was 99.3% sensitive.

CONCLUSIONS

This time-based model may aid search managers in the decision about starting a search or changing search tactics for missing persons.

Childhood soccer injuries treated in U.S. emergency departments

OBJECTIVES

Soccer, an increasingly popular sport among children in the United States, is a common precipitant to injury-related emergency department (ED) visits. The authors estimated the number of children treated in EDs for soccer-related injuries and described the nature of these injuries.

METHODS

Data from the 2000 National Electronic Injury Surveillance System All Injury Program were used to estimate the overall number and rate of soccer injuries in children, calculate injury rates per 1,000 children, and describe the body regions affected and types of injuries. Results were stratified by five-year age groups (5-9 years, 10-14 years, and 15-19 years).

RESULTS

Approximately 144,600 children sustained soccer-related injuries in 2000 for a rate of 2.36 injuries per 1,000 children. Injury rates increased with age (0.8, 5-9 year olds; 3.1, 10-14 year olds; 3.2, 15-19 year olds). Common types of injuries were strains/sprains (36.7%), fractures (23.0%), and contusions (20.9%). Fractures decreased with age; sprains/strains increased with age. Commonly injured body regions varied by age. Wrist and finger injuries were most common (12.7% and 12.4%, respectively) in the youngest group; in the 10-14-year-old group, ankle and wrist injuries were most common (15.7% and 13.6%, respectively). In the oldest age group, ankle injuries were most common (21.9%), followed by knee injuries (17.6%).

CONCLUSIONS

Substantial numbers of children were treated in EDs for soccer-related injuries. Injury types and affected body regions varied by age. Injury prevention efforts to reduce soccer-related injuries may need to be age specific.

Regional Differences in Outcomes for Hospitalized Injured Patients

BACKGROUND

Our goal was to use a hospital population-based data set that was a sample of all injured patients admitted to a hospital in the United States to develop universal measures of outcome and processes of care.

METHODS

Patients with a primary discharge diagnosis of injury (ICD-9 800 to 959) in the HCUP/Nationwide Inpatient Sample for the years 1995 to 2000 were used to estimate the annual number of hospitalized injured patients. Using census data, we calculated age- and sex- adjusted average annual incidence rates for four census regions in the United States: Northeast, Midwest, South and West. Outcomes measured were annual rates per million populations of hospitalization rate, death rate, and potentially ineffective care (PIC) rate defined as >28 days of hospitalization ending in death. Length of stay (LOS) was calculated as total number of days annually hospitalized for injury for census regions per million populations.

RESULTS

Incidence rates per million populations and 95% confidence intervals for rate of hospitalizations for injury were: Northeast, 5596 (5338-5853); Midwest, 5516 (5316-5716); South, 5639 (5410-5869); West, 5307 (5071-5543). Incidence rates per million populations and 95% confidence intervals for rate of in-hospital deaths were: Northeast, 129 (119-139); Midwest, 131 (122-139); South, 141 (129-152); West, 114 (106-123). Incidence rates per million populations and 95% confidence intervals for rate of PIC were: Northeast, 11 (10-13); Midwest, 5 (4-5); South, 6 (5-7); West, 4 (3-4). Incidence rates per million populations and 95% confidence intervals for hospital days were: Northeast, 34 (32-36); Midwest, 30 (28-31); South, 30 (29-32); West, 26 (24-27).

CONCLUSION

Regional differences in outcomes and processes of care for hospitalized injured patients exist and may be influenced by hospital characteristics and region of the country. Research to identify the factors that cause these hospital and regional variations is needed. These observations suggest that to develop a uniform standard for quality of care, it will be essential to have valid and robust hospital population-based measures.

Reasons why patients choose an ambulance and willingness to consider alternatives

OBJECTIVES

To test a hypothesis that patients would accept alternatives to transport to an emergency department (ED) by ambulance and to evaluate factors related to patient willingness to consider alternatives. Concerns about resource utilization have prompted emergency medical services (EMS) systems to explore alternatives to ambulance transport to an ED, but studies have evaluated the safety of alternatives, not patient preferences.

METHODS

Trained research assistants surveyed patients transported by ambulance to a university ED. Interfacility transfers, trauma patients, and critically ill patients were excluded. The primary outcome was willingness to accept one of several presented alternatives to ambulance transport to the ED for that visit. Demographic and clinical factors were evaluated for association with willingness to consider alternatives. Relative risks (RR) and 95% confidence intervals (95% CI) were determined by using Mantel-Haenszel stratified methods.

RESULTS

Three hundred fifteen subjects completed the survey. Two hundred forty-seven (78.4%) were willing to consider at least one alternative. One hundred ninety-four (61.6%) were willing to consider transportation by car, and 177 (56.2%) were willing to consider transportation by taxi. Factors associated with willingness to consider alternatives included the following: age 18-65 years (RR, 1.25; 95% CI = 1.03 to 1.49), being unemployed (RR, 1.08; 95% CI = 1.08 to 1.33), use of the ED for routine care (RR, 1.25; 95% CI = 1.17 to 1.35), and not being admitted to the hospital (RR, 1.19; 95% CI = 1.04 to 1.40). Race, gender, health insurance status, and EMS interventions en route were not associated with willingness to consider transportation alternatives.

CONCLUSIONS

Many patients transported by ambulance to an ED would have considered an alternative, if one were offered.

Changes in access to primary care for Medicaid beneficiaries and the uninsured: the emergency department perspective

Reductions in scope of benefits and stricter premium and co-payment policies in the Oregon Health Plan (OHP) led to a large drop in OHP enrollment. Outpatient psychiatric benefits were eliminated for approximately 25% of enrollees. One measure of access to care is ED use. We used administrative data from our ED from August 1, 2001, through June 30, 2004, comparing ED use before vs after the March 1, 2003, cutbacks. Before the cutbacks, 38% of ED visits were by OHP beneficiaries, falling to 32% afterward. Visits by the uninsured rose from 18% before to 22% afterward. The proportion of visits for psychiatric conditions covered by OHP fell from 41% [corrected] to 31% [corrected], although the proportion by uninsured patients rose from 16% to 23%. These findings suggest a worrisome reduction in access to medical care for uninsured Oregonians and unstable access for OHP enrollees, especially for behavioral health conditions.

Electronic Reporting of Pelvic Inflammatory Disease From an Emergency Department

BACKGROUND AND OBJECTIVES

Pelvic inflammatory disease (PID) is a clinically diagnosed condition that is preventable and underreported. We developed an electronic emergency department (ED) PID reporting system by using an automatic and secure system to send computerized clinician PID diagnoses to the state health department.

GOAL

The goal of this study was to assess if electronic transmission of ED PID data could enhance the completeness and timeliness of PID surveillance.

STUDY DESIGN

We conducted a retrospective chart review.

METHODS

To validate electronic ED diagnoses, we reviewed charts of 157 women with 7 clinicians' diagnoses compatible with PID. We determined which women met the Centers for Disease Control and Prevention (CDC) PID surveillance case definition and determined the positive predictive values of electronic ED diagnoses of PID. We compared completeness of electronic PID reporting with state sexually transmitted disease surveillance.

RESULTS

Three diagnoses were appropriate for electronic PID surveillance. Information on women with these diagnoses is sent daily to the health department with no extra effort needed from ED clinicians. Less than 10% of women who met the CDC PID case definition were reported within 6 months through conventional methods.

CONCLUSIONS

Electronic ED surveillance will improve completeness and timeliness of PID reporting.

HIV infection risk, behaviors, and attitudes about testing: are perceptions changing?

BACKGROUND

People at high risk for HIV infection could be increasing their risk behaviors, especially now that improved treatments for HIV infection are available.

GOAL

The goal was to investigate whether risk behaviors, perceptions of personal risk for HIV infection, and attitudes toward HIV testing among high-risk persons in Oregon differed in 1996 and 1998.

STUDY DESIGN

Data from the HIV Testing Survey (HITS), a cross-sectional survey administered to HIV-negative men who have sex with men (MSM), heterosexual adults at high-risk for sexually transmitted diseases (STD), and intravenous drug users (IDUs) at high risk for HIV infection in 1996 (HITS-I), were compared with data from a similar group surveyed in 1998 (HITS-II).

RESULTS

Proportions of participants reporting specific risk behaviors remained relatively constant in 1996 and 1998. Personal risk of HIV infection was perceived as low by 54% of HITS-II participants and 61.2% of HITS-I participants (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.9-1.7). IDUs in HITS-II were more likely than IDUs in HITS-I to perceive their risk as low (OR, 2.1; 95% CI, 1.2-3.7).

CONCLUSION

Persons at high risk might underestimate their risk for HIV infection while practicing risky behaviors. The prevalence of risk behaviors in these populations could be considered the baseline against which to measure future prevention efforts.

Is it possible to safely triage callers to EMS dispatch centers to alternative resources?

OBJECTIVES

To develop guidelines allowing emergency medical services (EMS) dispatchers to safely match callers to an EMS response or, alternatively, to a nontraditional resource.

METHODS

This was a prospective cohort study of callers to an urban EMS dispatch center and an associated review of EMS patient care forms and emergency department (ED) patient care records. The following five "nature codes" (patient chief complaints) were included: back pain, fall, bleeding or laceration, sick, and trauma. Callers included in the study had been assigned the lowest severity level (Alpha), according to existing dispatch criteria. An a priori list of EMS and ED "important findings," indicating need for an EMS response, was used as the outcome variable. Classification and regression tree (CART) analysis was used to develop a decision rule to further identify a low-risk subgroup of patients who could potentially be served by alternative resources.

RESULTS

From November 1, 1998, to May 31, 1999, 656 subjects were entered into the study, including 263 males (40%) and 389 females (59%). The mean age was 51 years (range, 0-101 years). One hundred twenty-five (19%) callers had an important EMS finding, including the administration of comfort medications, morphine, benzodiazepines, and droperidol. Forty-six subjects (7%) had an important ED finding. When EMS and ED findings were combined, 158 subjects (24%) had an "important finding." Using CART analysis, having an age <12 years predicted a subset of patients who did not have an important finding suggesting the need for an EMS response. Using cross-validation, this decision rule had a 99% sensitivity, 13% specificity, and 98% negative predictive value.

CONCLUSION

The authors were able to use a demographic variable (age) to predict a population of callers to a 911 dispatch center triaged to the lowest acuity category, who have a very low risk of having an EMS or ED important finding. The decision rule developed here is preliminary, requiring further validation.