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Dive into the research topics where Nathan N. O’Hara is active.

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Featured researches published by Nathan N. O’Hara.


PLOS ONE | 2015

Healthcare Worker Preferences for Active Tuberculosis Case Finding Programs in South Africa: A Best-Worst Scaling Choice Experiment

Nathan N. O’Hara; Lilla Roy; Lyndsay M. O’Hara; Jerry Spiegel; Larry D. Lynd; J. Mark FitzGerald; Annalee Yassi; Letshego E. Nophale; Carlo A. Marra

Objective Healthcare workers (HCWs) in South Africa are at a high risk of developing active tuberculosis (TB) due to their occupational exposures. This study aimed to systematically quantify and compare the preferred attributes of an active TB case finding program for HCWs in South Africa. Methods A Best–Worst Scaling choice experiment estimated HCW’s preferences using a random-effects conditional logit model. Latent class analysis (LCA) was used to explore heterogeneity in preferences. Results “No cost”, “the assurance of confidentiality”, “no wait” and testing at the occupational health unit at one’s hospital were the most preferred attributes. LCA identified a four class model with consistent differences in preference strength. Sex, occupation, and the time since a previous TB test were statistically significant predictors of class membership. Conclusions The findings support the strengthening of occupational health units in South Africa to offer free and confidential active TB case finding programs for HCWs with minimal wait times. There is considerable variation in active TB case finding preferences amongst HCWs of different gender, occupation, and testing history. Attention to heterogeneity in preferences should optimize screening utilization of target HCW populations.


Value in Health | 2017

A Cost-Effectiveness Analysis of Reverse Total Shoulder Arthroplasty versus Hemiarthroplasty for the Management of Complex Proximal Humeral Fractures in the Elderly

Georg Osterhoff; Nathan N. O’Hara; Jennifer D’Cruz; Sheila Sprague; Nick Bansback; Nathan Evaniew; Gerard P. Slobogean

BACKGROUND There is ongoing debate regarding the optimal surgical treatment of complex proximal humeral fractures in elderly patients. OBJECTIVES To evaluate the cost-effectiveness of reverse total shoulder arthroplasty (RTSA) compared with hemiarthroplasty (HA) in the management of complex proximal humeral fractures, using a cost-utility analysis. METHODS On the basis of data from published literature, a cost-utility analysis was conducted using decision tree and Markov modeling. A single-payer perspective, with a willingness-to-pay (WTP) threshold of Can


Burns | 2014

Bed net related burns at Mulago National Referral Hospital, Uganda: A case series report

Edris W. Kalanzi; Lyndsay M. O’Hara; Nathan N. O’Hara; James C. Boyle

50,000 (Canadian dollars), and a lifetime time horizon were used. The incremental cost-effectiveness ratio (ICER) was used as the studys primary outcome measure. RESULTS In comparison with HA, the incremental cost per quality-adjusted life-year gained for RTSA was Can


Journal of Pediatric Orthopaedics | 2017

Variation Among Pediatric Orthopaedic Surgeons When Diagnosing and Treating Pediatric and Adolescent Distal Radius Fractures

Karan Dua; Matthew K. Stein; Nathan N. O’Hara; Brian K. Brighton; William L. Hennrikus; Martin J. Herman; J. Todd Lawrence; Charles T. Mehlman; Norman Y. Otsuka; M. Wade Shrader; Brian G. Smith; Paul D. Sponseller; Joshua M. Abzug

13,679. One-way sensitivity analysis revealed the model to be sensitive to the RTSA implant cost and the RTSA procedural cost. The ICER of Can


Injury-international Journal of The Care of The Injured | 2018

Radiographic predictors of symptomatic locking screw removal after treatment of tibial fractures with intramedullary nails

Daniel Mascarenhas; Daniel Connelly; Nathan N. O’Hara; Mark J. Gage; Max Coale; Theodore T. Manson; Robert V. O’Toole

13,679 is well below the WTP threshold of Can


BMJ Open | 2018

Patient preferences for nutritional supplementation to improve fracture healing: a discrete choice experiment

Elizabeth M. Nichols; Nathan N. O’Hara; Yasmin Degani; Sheila Sprague; Jonathan D. Adachi; Mohit Bhandari; Michael F. Holick; Daniel Connelly; Gerard P. Slobogean

50,000, and probabilistic sensitivity analysis demonstrated that 92.6% of model simulations favored RTSA. CONCLUSIONS Our economic analysis found that RTSA for the treatment of complex proximal humeral fractures in the elderly is the preferred economic strategy when compared with HA. The ICER of RTSA is well below standard WTP thresholds, and its estimate of cost-effectiveness is similar to other highly successful orthopedic strategies such as total hip arthroplasty for the treatment of hip arthritis.


Injury-international Journal of The Care of The Injured | 2017

Radiographic predictors of symptomatic screw removal after retrograde femoral nail insertion

Max Hamaker; Nathan N. O’Hara; W. Andrew Eglseder; Marcus F. Sciadini; Jason W. Nascone; Robert V. O’Toole

BACKGROUND Insecticide-treated bed nets are essential tools to prevent malaria in endemic regions, however, increasing trends in bed net related burns in Kampala, Uganda are concerning. METHODS Data were collected from burns unit admission records at Mulago National Referral Hospital in Kampala, Uganda for the years 2008-2011 inclusive. Retrospective analyses on the characteristics of patients admitted with bed net related burns within this period were conducted. RESULTS A total of 45 patients were admitted to the burns unit with bed net related burns during the study period. Most burns occurred among individuals who were 0-1 years old (33.3%) and 26-35 years old (24.2%) and the majority were male (71%). Bed net related burns at Mulago Hospital are severe, as evidenced by the fact that 15 of 45 patients died (crude mortality rate=33%) and that 26 patients (57.8%) had total body surface area burn percentages that were greater than 20%. The average length of stay in hospital for patients with bed net related burns was 30.4 days. CONCLUSION Organizations responsible for malaria prevention should consider incorporating fire and burn prevention awareness, strategies and training into their bed net distribution programs.


Global Health Promotion | 2017

Engaging youth in rural Uganda in articulating health priorities through Photovoice.

Daniel Esau; Pak To Ho; Geoffrey K. Blair; Damian Duffy; Nathan N. O’Hara; Videsh Kapoor; Margaret Ajiko

Background: Distal radius fractures are the most common injury in the pediatric population. The purpose of this study was to determine the variation among pediatric orthopaedic surgeons when diagnosing and treating distal radius fractures. Methods: Nine pediatric orthopaedic surgeons reviewed 100 sets of wrist radiographs and were asked to describe the fracture, prescribe the type of treatment and length of immobilization, and determine the next follow-up visit. κ statistics were performed to assess the agreement with the chance agreement removed. Results: Only fair agreement was present when diagnosing and classifying the distal radius fractures (κ=0.379). There was poor agreement regarding the type of treatment that would be recommended (κ=0.059). There was no agreement regarding the length of immobilization (κ=−0.004). Poor agreement was also present regarding when the first follow-up visit should occur (κ=0.088), whether or not new radiographs should be obtained at the first follow-up visit (κ=0.133), and if radiographs were necessary at the final follow-up visit (κ=0.163). Surgeons had fair agreement regarding stability of the fracture (κ=0.320). A subgroup analysis comparing various traits of the treatment immobilization showed providers only had a slight level of agreement on whether splint or cast immobilization should be used (κ=0.072). There was poor agreement regarding whether long-arm or short-arm immobilization should be prescribed (κ=−0.067). Twenty-three of the 100 radiographs were diagnosed as a torus/buckle fracture by all 9 surgeons. κ analysis performed on all the treatment and management questions showed that each query had poor agreement. Conclusions: The interobserver reliability of diagnosing pediatric distal radius fractures showed only fair agreement. This study demonstrates that there is no standardization regarding how to treat these fractures and the length of immobilization required for proper fracture healing. Better classification systems of distal radius fractures are needed that standardize the treatment of these injuries. Level of Evidence: Level II.BACKGROUND Distal radius fractures are the most common injury in the pediatric population. The purpose of this study was to determine the variation among pediatric orthopaedic surgeons when diagnosing and treating distal radius fractures. METHODS Nine pediatric orthopaedic surgeons reviewed 100 sets of wrist radiographs and were asked to describe the fracture, prescribe the type of treatment and length of immobilization, and determine the next follow-up visit. κ statistics were performed to assess the agreement with the chance agreement removed. RESULTS Only fair agreement was present when diagnosing and classifying the distal radius fractures (κ=0.379). There was poor agreement regarding the type of treatment that would be recommended (κ=0.059). There was no agreement regarding the length of immobilization (κ=-0.004).Poor agreement was also present regarding when the first follow-up visit should occur (κ=0.088), whether or not new radiographs should be obtained at the first follow-up visit (κ=0.133), and if radiographs were necessary at the final follow-up visit (κ=0.163). Surgeons had fair agreement regarding stability of the fracture (κ=0.320).A subgroup analysis comparing various traits of the treatment immobilization showed providers only had a slight level of agreement on whether splint or cast immobilization should be used (κ=0.072). There was poor agreement regarding whether long-arm or short-arm immobilization should be prescribed (κ=-0.067).Twenty-three of the 100 radiographs were diagnosed as a torus/buckle fracture by all 9 surgeons. κ analysis performed on all the treatment and management questions showed that each query had poor agreement. CONCLUSIONS The interobserver reliability of diagnosing pediatric distal radius fractures showed only fair agreement. This study demonstrates that there is no standardization regarding how to treat these fractures and the length of immobilization required for proper fracture healing. Better classification systems of distal radius fractures are needed that standardize the treatment of these injuries. LEVEL OF EVIDENCE Level II.


Canadian Journal of Surgery | 2016

Are patients willing to pay for total shoulder arthroplasty? Evidence from a discrete choice experiment

Nathan N. O’Hara; Gerard P. Slobogean; Tima Mohammadi; Carlo A. Marra; Milena R. Vicente; Amir Khakban; Michael D. McKee

INTRODUCTION The purpose of this study was to determine the radiographic parameters associated with symptomatic locking screw removal after intramedullary tibial nail insertion. Our hypothesis was that locking screws located closer to joints and those extending longer than the width of the bone result in more symptomatic implant removal. METHODS We conducted a retrospective cohort study at our Level I trauma center. Seventy-five patients underwent surgical removal of symptomatic locking screws from 2007 to 2014 and were compared with a control group of 122 patients from the same time period who did not undergo symptomatic locking screw removal. Our main outcome measures were radiographic and demographic factors associated with implant removal. RESULTS Multivariable regression indicated that a proximal locking screw that started anterolateral and was directed posteromedial was the strongest radiographic predictor of symptomatic removal (odds ratio [OR], 2.83; p = 0.03). An Injury Severity Score <11 (OR, 3.10; p < 0.001) and a body mass index <25 kg/m2 (OR, 2.15; p = 0.02) were also associated with locking screw removal. The final prediction model discriminated patients requiring symptomatic locking screw removal with moderate accuracy (area under the receiver operating characteristic curve = 0.73). CONCLUSIONS The strongest radiographic predictor for symptomatic locking screw removal after tibial nail insertion was the direction of the most proximal locking screw. In contrast to previous research on retrograde femoral nails, tibial locking screws that were closer to the joints were not associated with an increased likelihood of symptomatic screw removal. Clinicians can use these data to help counsel patients regarding the likelihood of symptomatic screws and perhaps to help guide screw placement in cases with multiple options.


Injury-international Journal of The Care of The Injured | 2016

Economic loss due to traumatic injury in Uganda: The patient's perspective

Nathan N. O’Hara; Rodney Mugarura; Jeffrey Potter; Trina Stephens; M. Marit Rehavi; Patrick Francois; Piotr A. Blachut; Peter J. O’Brien; Bababunmi K. Fashola; Alex Mezei; Tito Beyeza; Gerard P. Slobogean

Objective Vitamin D is often prescribed as an adjuvant therapy to aid fracture healing due to its biological role in bone health. However, the optimal frequency, dosage and duration of vitamin D supplementation for non-osteoporotic fracture healing has not been established. The objective of this study was to determine patient preferences for fracture healing relative to hypothetical vitamin D supplementation dosing options. Design Discrete choice experiment. Setting Level 1 trauma centre in Baltimore, Maryland, USA. Participants 199 adult (18–60 years) patients with a fracture. Primary outcome measures Parameter estimates of utility for fracture healing relative to dosing regimens were analysed using hierarchical Bayesian modelling. Results A reduced risk of reoperation (34.3%) and reduced healing time (24.4%) were the attributes of greatest relative importance. The highest mean utility estimates were for a one-time supplementation dose (ß=0.71, 95% CI 0.41 to 1.00) followed by a reduced risk of reoperation (ß=0.41 per absolute % reduction, 95% CI 0.0.36 to 0.46). Supplementation for 24 weeks in duration (ß=−0.83, 95% CI −1.00 to −0.67) and a daily supplement (ß=−0.29, 95% CI −0.47 to −0.11) had the lowest mean utilities. The ‘no supplement’ option had a large negative value suggesting supplementation was generally desirable in this sample population. Among other possible clinical scenarios, patients expected a 2% reduction in the absolute risk of reoperation or a 3.1-week reduction in healing time from the baseline to accept a treatment regimen requiring two separate doses of supplementation, two blood tests and a cost of

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Karan Dua

SUNY Downstate Medical Center

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Jeffrey Potter

University of British Columbia

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Lyndsay M. O’Hara

University of British Columbia

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Peter J. O’Brien

University of British Columbia

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Piotr A. Blachut

University of British Columbia

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