Evaluation of an algorithm ascertaining cases of osteonecrosis of the jaw in the Swedish National Patient Register

The trend of dental check-up and prevalence of dental complications following the use of bone modifying agents in patients with metastatic breast and prostate cancer: analysis of data from the Korean National Health Insurance Service

BACKGROUND

Bone-modifying agents (BMA) are key components in the management of cancer patients with bone metastasis. Despite their clinical benefits, the use of BMA is associated with dental adverse events (AEs) including medication-related osteonecrosis of the jaw (MRONJ). This study investigated the frequency of dental surveillance before BMA treatment and the prevalence of dental AEs including MRONJ, after BMA treatment in patients with bone metastasis from breast and prostate cancer using data from the national health insurance system.

METHODS

Data, including age, cancer diagnosis, administered BMA, and dental AEs during cancer treatment, of patients with bone metastasis from breast and prostate cancer who received at least one infusion of BMA between 2007 and 2019 were extracted from the Korean National Health Insurance Service (KNHIS) dataset.

RESULTS

Of the 15,357 patients who received BMA, 1,706 patients (11.1%) underwent dental check-ups before BMA treatment. The proportion of patients receiving dental check-up increased from 4.4% in 2007 to 16.7% in 2019. Referral to dentists for a dental check-up was more active in clinics/primary hospitals than general/tertiary hospitals, and medical doctors and urologists actively consulted to dentists than general surgeons, regardless of the patient's health insurance status. After BMA treatment, 508 patients (3.8%) developed dental AEs, including abscess (42.9%), acute periodontitis (29.7%), acute pericoronitis (14.9%), and MRONJ (12.5% of dental AEs cases, 0.5% of total BMA treated patients).

CONCLUSIONS

Considering the long treatment period in patients with metastatic cancer, coordination between dentists and oncologists is necessary to ensure appropriate dental management before the initiation of BMA.

Medication-Related Osteonecrosis of the Jaw in Cancer Patients: Result from the OneFlorida Clinical Research Consortium

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but severely debilitating drug-induced bone disorder in the jawbone region. The first MRONJ was reported in 2003 after bisphosphonate (BP) exposure. Recently, other drugs, such as receptor activator of NF-κB ligand (RANKL) inhibitor denosumab and antiangiogenic agents, were also associated with MRONJ. The purpose of this study was to evaluate the incidence and risk factors for MRONJ related to BPs or denosumab in cancer patients in real-world clinical settings using data from the OneFlorida Clinical Research Consortium. We queried the electronic health records of participants with prescriptions of intravenous (IV) BPs or denosumab between January 1, 2012, and September 1, 2021, in the OneFlorida Consortium. Time to MRONJ diagnosis was evaluated using the Kaplan-Meier method, and Cox regression analysis was performed to estimate the adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for MRONJ. A total of 5689 participants had one or more prescriptions of IV BP or denosumab within this study period and were included in this study. Among these participants, 52 (0.9%) had a diagnosis of MRONJ. The overall rate of MRONJ was 0.73%, 0.86%, and 3.50% in the cancer patients treated with IV BPs, denosumab, and sequential IV BPs and denosumab, respectively. The risk of MRONJ was similar in participants treated with denosumab alone compared to those treated with IV BPs alone (HR: 1.25, 95% CI: 0.66-2.34, p = .49). Patients with sequential prescription of IV BP and denosumab were at much higher risk for MRONJ, with an adjusted HR of 4.49, 95% CI of 1.96-10.28, p = .0004. In conclusion, in real-world clinical settings, the rates of MRONJ associated with IV BPs and denosumab were similar, while the sequential treatment of these two drug classes was associated with a much higher risk of MRONJ. © 2022 American Society for Bone and Mineral Research (ASBMR).

Assessment of a Claims-Based ICD-9 and ICD-10 Medication-Related Osteonecrosis of the Jaw Algorithm in the United States

PURPOSE

Medication-related osteonecrosis of jaw (MRONJ) is associated with certain drug therapies. Pharmacoepidemiologic studies often rely on electronic healthcare data to assess adverse events following drug exposure. Few studies have developed and validated claims-based MRONJ identification algorithms. This study assessed the performance of claims-based MRONJ algorithms by chart review of potential cases among postmenopausal (PM) women and women with postmenopausal osteoporosis (PMO).

METHODS

Among PM and PMO women sourced from a large US commercial health insurance database affiliated with Optum, potential cases were identified by International Classification of Diseases, 9th and 10th Revisions (ICD-9, ICD-10) diagnosis codes; 200 were selected for chart retrieval, with the goal of obtaining 100 charts in each coding era. Procured charts were redacted and then reviewed by an oral surgeon who determined case status. Positive predictive values (PPV) and 95% confidence intervals (CI) were calculated overall, by cohorts, and coding eras. Baseline characteristics were assessed. Two potential algorithm refinements were explored: using a restricted set of ICD codes; requiring antibiotic use after MRONJ diagnosis.

RESULTS

A total of 1273 potential cases were identified. Of the 200 potential cases selected, 104 (52%) were procured, and six cases were confirmed (PPV 5.8%, 95% CI 2.2, 12.1). Baseline characteristics were largely similar across all strata. Potential algorithm refinements yielded marginal PPV improvement.

CONCLUSION

This study identified a small number of confirmed cases, and the resulting PPVs were low, but consistent with reported studies. Potential algorithm refinements yielded minimal improvements. To our knowledge, this study is the first to report on the identification of MRONJ using ICD-10 codes in the US.

A multicenter observational study on Medication-Related Osteonecrosis of the Jaw (MRONJ) in advanced cancer and myeloma patients of a cancer network in North-Western Italy

BACKGROUND

Incidence of Medication-Related Osteonecrosis of the Jaw (MRONJ) related to cancer and myeloma treatments is undetermined, with scarce data varying from 2 to 7.8/million/year in limited investigated populations. A 9-years [2009-2018] regional-wide survey was conducted, deploying the North-Western Italy Cancer Network ("Rete Oncologica Piemonte e Valle d'Aosta"), to assess number and main characteristics of MRONJ cases among myeloma/cancer patients, within a population of 4.5 million inhabitants.

MATERIAL AND METHODS

MRONJ cases were collected retrospectively from January 2009 to June 2015; from July 2015 to December 2018, data were collected prospectively. Number of new MRONJ cases per year, underlying disorder, drug(s) administered, treatment duration, site and onset timing of MRONJ were detailed.

RESULTS

459 MRONJ cases were identified. Primary diseases were breast cancer (46%), prostate cancer (21%), myeloma (19%), and other types of carcinoma (14%). Patients received antiresorptive treatment either alone (399; 88.47%) or in combination with biological agents (52; 11.53%); 8 patients (1.7%) received only antiangiogenic drugs. Zoledronic acid [388] and denosumab [59] were the most frequently administered drugs. Mandible was involved in 296 (64,5%) cases. Number of new MRONJ cases was stable from 2009 to 2015, with a mean of 51.3 cases per year (raw incidence: 11.6/million/year), declining in the 2016-2018 years to 33.3 cases per year (raw incidence: 7.5/million/year).

CONCLUSIONS

With such discrepancy of cases overtime being partially explicable, number of new MRONJ cases per year are consistent with those observed in a previous study [2003-2008] in the same region, being instead higher than those reported in other populations.

Incidence of and risk for osteonecrosis of the jaw in Korean osteoporosis patients treated with bisphosphonates: A nationwide cohort-study

PURPOSE

To estimate the incidence of osteonecrosis of the jaw (ONJ) in patients treated with bisphosphonates (BPs) and to identify clinical risk factors that increase the risk for ONJ in Korean osteoporosis patients.

METHODS

We used data acquired from the Korean National Health Insurance Service. Among 2,140,149 participants with osteoporosis in 2012, we selected 164,926 new BP users and 164,926 age- and sex-matched control subjects. The control group included only patients with no prescriptions for BPs between January 1, 2011, and December 31, 2016. Participants were followed for 4 years.

RESULTS

Over the 4-year follow-up period, the cumulative incidence rates of ONJ were 20.9 and 6.9 per 100,000 person-years in the BP and control groups, respectively. The BP group had an increased risk for ONJ compared to the control group after adjusting for multiple variables (hazard ratio [HR] 3.72, 95% CI 2.70-5.11). Advanced age (≥70 years), comorbid diseases such as diabetes, hypertension, and rheumatoid arthritis (RA) were independent risk factors for the development of ONJ. In addition, tooth extraction (HR 9.85), gingivitis, and periodontal disease (HR 4.78) were strongly associated with ONJ.

CONCLUSIONS

ONJ incidence was 21 per 100,000 person-years in osteoporosis patients receiving bisphosphonates. Clinical factors including advanced age, diabetes, RA, dental disease, as well as BP use were significantly associated with ONJ.

Is implant surgery a risk factor for osteonecrosis of the jaw in older adult patients with osteoporosis? A national cohort propensity score-matched study

OBJECTIVES

This study aimed to investigate the association between dental implant therapy and osteonecrosis of the jaw (ONJ) in osteoporotic patients and the relationship between tooth extraction, dental implantation, and ONJ.

MATERIAL AND METHODS

This retrospective cohort study used the Customized Health Information Data from the National Health Insurance Corporation in South Korea. The study population included patients older than 70 years with a history of osteoporosis; the cases included patients who had undergone dental implant surgery between July 2014 and July 2016 with specific procedure codes. The case and control cohorts were stratified by tooth extraction because it was the strongest risk factor to consider in this study. Each group of patients was matched using the propensity score. To investigate the relationship between dental implants and ONJ, a Cox proportional hazard model was applied to socio-economic factors, comorbidities, and bisphosphonates (BPs). All analyses were conducted using SAS statistical software.

RESULTS

Based on the fully adjusted model, the propensity score-matched osteoporosis patients with dental implants had a 0.51 times hazard ratio of osteonecrosis. On the contrary, tooth extraction was associated with a higher risk of ONJ (HR = 5.89). The patients with rheumatoid arthritis (RA) and those using BPs had a higher HR, respectively, 6.80 and 4.09 HR (p < .001).

CONCLUSIONS

Dental implantation was not a risk factor and patients with implants show rather lower ratios. However, older osteoporotic Korean patients who had undergone tooth extraction had higher risks of ONJ. A significantly higher risk of ONJ was associated with RA and BPs as well.

Use of oral bisphosphonates and risk of hospital admission with osteonecrosis of the jaw: Large prospective cohort study in UK women

About 1 in 10 postmenopausal UK women are currently prescribed oral bisphosphonates, but there are concerns about their adverse effects. Osteonecrosis of the jaw is a recognised uncommon but important side effect of intravenous bisphosphonates, but epidemiological evidence on risk of osteonecrosis of the jaw associated with oral bisphosphonate use is less conclusive. The incidence of hospital admission with osteonecrosis of the jaw was examined among 521,695 Million Women Study participants, aged 64.7 years at baseline. Cox proportional hazards regression was used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs) associated with use of oral bisphosphonates in postmenopausal women followed-up by record-linkage to National Health Service hospital admission databases. During mean follow-up of 8.2 years per woman, 100 women were admitted to hospital with first recorded osteonecrosis of the jaw, at mean age 72.4 years. Almost a third (29/100) of the cases had ever-used oral bisphosphonates. Ever-users had a six-fold increased risk of hospital admission for osteonecrosis of the jaw, when compared with never-users (adjusted RR = 6.09, 95% CI 3.83-9.66; p < 0.0001). The relative risk for osteonecrosis of the jaw in never-users of oral bisphosphonates was increased in women with prior cancer (RR = 3.40, 2.22-5.22, p < 0.0001). The estimated absolute risk of hospital admission for osteonecrosis of the jaw over a 5-year period from age 70 to 74 in women without prior cancer was 0.09 per 1000 in never-users and 0.69 per 1000 in ever-users of oral bisphosphonates. In this UK population of postmenopausal women, use of oral bisphosphonates was associated with a 6-fold increased risk of hospital admission with osteonecrosis of the jaw, accounting for around one-third of cases, with an excess risk of about 0.6/1000 users over 5 years.

Drug holiday patterns and bisphosphonate-related osteonecrosis of the jaw

OBJECTIVES

There is limited evidence regarding the appropriate length of a bisphosphonate (BP) holiday to reduce the risk of osteonecrosis of the jaw (ONJ). In this cross-sectional study, we investigated the population-based patterns of the gaps between BP discontinuation and ONJ diagnosis.

SUBJECTS AND METHODS

We used the claims database of the National Health Insurance Service in Korea. Among BP users between 2006 and 2015, incident ONJ cases during 2010-2015 with no history of ONJ in the last 4 years were identified. We assessed the time gap from the last BP administration to ONJ diagnosis.

RESULTS

Among 1,569 incident ONJ cases, 836 (53.3%) occurred after BP discontinuation. The cumulative proportions of ONJ occurrence within 1 month, 3 months, 1 year, 2 years, and 3 years after discontinuation were 58.9%, 70.8%, 87.0%, 93.2%, and 96.1%, respectively. The length of drug holidays showed no significant difference between patients with or without comorbid cancer and diabetes mellitus (p-value, 0.12 and 0.52, respectively). However, the use of injectable BP formulations significantly affected ONJ incidence (p < 0.01).

CONCLUSIONS

Most ONJ cases occurred within 3 years from BP suspension, with a higher prevalence among BP injection users with 1 year or lesser BP holiday.

Risk of Jaw Osteonecrosis After Intravenous Bisphosphonates in Cancer Patients and Patients Without Cancer

OBJECTIVE

To compare the risk of jaw osteonecrosis after intravenous (IV) bisphosphonate administered to patients with cancer vs patients without cancer.

PATIENTS AND METHODS

We conducted a retrospective cohort study of a 5% national sample of Medicare patients administered IV bisphosphonate from January 1, 2008, through December 31, 2013, for cancer vs noncancer indications. Probable jaw osteonecrosis was estimated with an algorithm including diagnoses, surgical procedures, and imaging studies. A non-IV bisphosphonate comparison group included patients prescribed an oral bisphosphonate for 30 days or less.

RESULTS

During follow-up, 40 (0.42%) out of 9482 patients with cancer developed probable jaw osteonecrosis compared with 8 (0.05%) out of 16,046 patients without cancer. In a Cox multivariable survival analysis controlling for patient characteristics and number of IV zoledronic infusions, patients without cancer had a hazard ratio of 0.17 (95% CI, 0.06-0.46) for developing jaw osteonecrosis compared with those with cancer. The lower rate of jaw osteonecrosis in patients without cancer was also confirmed in a number of sensitivity analyses.

CONCLUSION

The low rate of jaw osteonecrosis in patients with osteoporosis who receive IV bisphosphonate should be weighed against the benefit of those agents in preventing hip and other fractures.

The Validity of Claims-Based Algorithms to Identify Serious Hypersensitivity Reactions and Osteonecrosis of the Jaw

Validation of claims-based algorithms to identify serious hypersensitivity reactions and osteonecrosis of the jaw has not been performed in large osteoporosis populations. The objective of this project is to estimate the positive predictive value of the claims-based algorithms in older women with osteoporosis enrolled in Medicare. Using the 2006-2008 Medicare 5% sample data, we identified potential hypersensitivity and osteonecrosis of the jaw cases based on ICD-9 diagnosis codes. Potential hypersensitivity cases had a 995.0, 995.2, or 995.3 diagnosis code on emergency department or inpatient claims. Potential osteonecrosis of the jaw cases had ≥1 inpatient or outpatient physician claim with a 522.7, 526.4, 526.5, or 733.45 diagnosis code or ≥2 claims of any type with a 526.9 diagnosis code. All retrieved records were redacted and reviewed by experts to determine case status: confirmed, not confirmed, or insufficient information. We calculated the positive predictive value as the number of confirmed cases divided by the total number of retrieved records with sufficient information. We requested 412 potential hypersensitivity and 304 potential osteonecrosis of the jaw records and received 174 (42%) and 84 (28%) records respectively. Of 84 potential osteonecrosis of the jaw cases, 6 were confirmed, resulting in a positive predictive value (95% CI) of 7.1% (2.7, 14.9). Of 174 retrieved potential hypersensitivity records, 95 were confirmed. After exclusion of 25 records with insufficient information for case determination, the overall positive predictive value (95% CI) for hypersensitivity reactions was 76.0% (67.5, 83.2). In a random sample of Medicare data, a claim-based algorithm to identify serious hypersensitivity reactions performed well. An algorithm for osteonecrosis of the jaw did not, partly due to the inclusion of diagnosis codes that are not specific for osteoporosis of the jaw.

A Large National Cohort Study of the Association between Bisphosphonates and Osteonecrosis of the Jaw in Patients with Osteoporosis

The purpose of this study was to examine the association between bisphosphonate exposure and osteonecrosis of the jaw (ONJ) in Korean patients with osteoporosis. A nested case-control study was performed using the claims database during 2002 to 2010 provided by the National Health Insurance Service. We identified a cohort of individuals with diagnosis of osteoporosis during 2002 to 2010. Cases and controls were identified during 2004 to 2010, and the date of potential cases of ONJ was defined as the index date. Bisphosphonate exposure was evaluated during 2 y prior to the index date. The association between bisphosphonate exposure and ONJ was tested by performing a conditional logistic regression analysis for matched data, and odds ratios (ORs) with 95% confidence intervals (CIs) were presented. Subjects were classified as nonuser, recent user, past user, or continuous user, depending on the prescription of bisphosphonates in 2 periods (1 to 2 y and 0 to 1 y prior to the index date). Continuous users were defined as patients who were exposed to bisphosphonate in both periods. We also examined the impact of bisphosphonate medication compliance by measuring the cumulative duration of exposure (CDE) on the risk of ONJ. A total of 212 cases with ONJ and 2,120 controls matched by sex, age, income level, and insurance type were identified among 109,787 patients with osteoporosis out of 1,025,340 enrollees in the sample cohort. The odds of having ONJ after adjusting for patient comorbidities significantly increased in continuous users of bisphosphonates (OR, 3.9; 95% CI, 2.4 to 6.2) compared to nonusers. Increased odds of ONJ were observed as CDE increased. The adjusted OR in patients with 1.5 y < CDE ≤ 2 y prior to the index date was 7.8 (95% CI, 4.0 to 15.5) versus nonusers. Our study results support significantly increased occurrences of potential ONJ in patients with osteoporosis who were exposed to bisphosphonates compared to those without exposure.

Evaluation of an ICD-10 algorithm to detect osteonecrosis of the jaw among cancer patients in the Danish National Registry of Patients

PURPOSE

This study aimed to validate a predefined algorithm for osteonecrosis of the jaw (ONJ) among cancer patients in the Danish National Registry of Patients and to assess the nature of clinical information recorded in medical charts of ONJ patients.

METHODS

We identified potential ONJ cases recorded in 2005-2010 among cancer patients at the hospital Departments of Oral and Maxillofacial Surgery (DOMS) in three Danish regions, using a set of codes from the International Classification of Diseases, 10th revision (ICD-10). We abstracted DOMS charts of the potential cases, had the ONJ status adjudicated by an expert ONJ adjudication committee (ONJAC), and computed positive predictive values. For patients with ONJAC-confirmed ONJ, we abstracted the charts for information on ONJ clinical course. Sensitivity of the algorithm was computed using a separate sample of 101 known ONJ cases accrued in 2005-2011.

RESULTS

We identified 212 potential ONJ cases, of which 197 (93%) had charts available for abstraction. Eighty-three potential cases were confirmed by ONJAC, with a positive predictive value of 42% (95% confidence interval [CI] 35%-49%). DOMS charts of these 83 cases contained complete information on ONJ clinical course. Information about antiresorptive treatment was recorded for 84% of the patients. Among the 101 known ONJ cases, 74 had at least one prespecified ICD-10 code recorded in the Danish National Registry of Patients within ±90 days of the ONJ diagnosis (sensitivity 73%; 95%CI [64%-81%]).

CONCLUSIONS

The predefined algorithm is not adequate for monitoring ONJ in pharmacovigilance studies. Additional case-finding approaches, coupled with adjudication, are necessary to estimate ONJ incidence accurately.

Existing data sources for clinical epidemiology: Scandinavian Cohort for osteonecrosis of the jaw - work in progress and challenges

Osteonecrosis of the jaw (ONJ) is a severe side effect associated with antiresorptive treatment. Monitoring of ONJ using routine databases in Scandinavian countries is a challenge owing to lack of valid algorithms and to heterogeneous referral practices. The aim of this paper is to describe the process of establishing a Scandinavian ONJ Cohort enrolling all ONJ cases related to antiresorptive treatment arising in Denmark, Norway, and Sweden between 2011 and 2019. The initial purpose of the cohort is to support an ongoing pharmacovigilance study of denosumab and zoledronic acid in Denmark, Norway, and Sweden. The three countries, with their 199 clinics, departments, and units of oral and maxillofacial surgery, both hospital-based and freestanding, differ somewhat in referral practices of the ONJ patients. By directly contacting all providers of care to ONJ patients in the three countries, we established a network for reporting incident cases to each country's research database directly or through a member of the Scandinavian ONJ task force as a liaison. The task force includes a Scandinavian coordinator and three national coordinators collaborating directly with the clinics. A uniform ONJ registration form has been developed, and the relevant medical community has been informed either directly or through presentations at professional meetings. A website with study information is published in each country, and data entry is ongoing. This large-scale systematic uniform registration of ONJ cases in Denmark, Norway, and Sweden, with an underlying total population of more than 20 million people, merged into the Scandinavian ONJ Cohort, will contribute to better knowledge and understanding of this challenging group of patients, and ultimately, help improve patient care. The Scandinavian ONJ Cohort as a whole and its component national ONJ research databases may offer the potential for large-scale multinational intervention and safety studies in the future.

Children with hemodynamically significant congenital heart disease can be identified through population-based registers

Background

Epidemiological research is facilitated in Sweden by a history of national health care registers, making large unselected national cohort studies possible. However, for complex clinical populations, such as children with congenital heart disease (CHD), register-based studies are challenged by registration limitations. For example, the diagnostic code system International Classification of Diseases, 10th version (ICD-10) does not indicate the clinical significance of abnormalities, therefore may be of limited use if used as the sole parameter in epidemiological research. Palivizumab is indicated as a prophylactic treatment against respiratory syncytial virus infections in children with hemodynamically significant CHD.

Aim

The aim of the study reported here was to develop and validate an algorithm to identify children with hemodynamically significant CHD according to recommendations for palivizumab prophylaxis in register-based research.

Methods

By using a strategy of combining criteria for age at diagnosis, diagnostic codes, surgical procedure codes, and dispensing records, we created an algorithm to define the specific cases with hemodynamically significant CHD in which palivizumab could be advocated according to recommendations.

Results

The algorithm identified 928 children with hemodynamically significant CHD in the Swedish birth cohort born July 1, 2005 to December 31, 2010. A sensitivity (95% confidence interval) of 80% (70–88) for the algorithm was found by analyzing 121 children identified through local hospital data who were treated with palivizumab within a defined region and study period. The positive predictive value was estimated by medical record review in a random sample of 34 cases identified by the algorithm. In 79% (62–91) of these cases, the children were regarded as having hemodynamically significant CHD according to the recommendations for treatment with palivizumab.

Conclusion

It was possible to identify a subgroup of children with hemodynamically significant CHD using an epidemiological approach and an algorithm with high validity. Our results will enable well-powered national cohort studies of individuals with complex clinical conditions such as hemodynamically significant CHD.

Osteonecrosis of the jaw in patients treated with oral and intravenous bisphosphonates: experience in Sweden

OBJECTIVE

To describe the prevalence, inciting factors, and treatment outcomes of bisphosphonate-related osteonecrosis of the jaw (BRONJ) during the 2003-2010 period in southern Sweden (population, approximately 1.2 million people).

STUDY DESIGN

Patient records were searched for inflammatory conditions including unspecified inflammation, osteomyelitis, osteonecrosis due to drugs, and other osteonecrosis. Data on underlying disease, type of bisphosphonate (BP), inciting factor, location, stage, treatment, and treatment outcomes were collected.

RESULTS

Of the 341 patients identified, 55 had been diagnosed with BRONJ. Those with a malignant disease were treated with intravenous BPs, and those with osteoporosis were treated with oral BPs. All but 5 were treated with antibiotics and 47 with local resection. Healing was recorded in 79% of patients with osteoporosis and in 26% of patients with malignant disease.

CONCLUSIONS

Healing in patients with osteoporosis occurred more frequently than in patients with a malignant disease treated with intravenous BPs (P = .00009).

Study design considerations for a large simple trial of bisphosphonates

PURPOSE OF REVIEW

To evaluate design considerations for an osteoporosis large simple trial (LST).

RECENT FINDINGS

There is a growing need for more comparative effectiveness studies in osteoporosis. However, the design of such studies is challenged by issues surrounding study design, choosing comparator therapies, participant and outcome selection, data acquisition and data analysis.

SUMMARY

LSTs are real-world studies that can have high levels of generalizability, if designed properly. We propose novel approaches to LSTs focusing on some of the challenges associated with comparative effectiveness research in osteoporosis. In this review, we discuss these considerations in the context of bisphosphonate active comparator initiation and discontinuation trials, while presenting advantages and disadvantages of the various design aspects for such studies.

Validity of an algorithm to identify osteonecrosis of the jaw in women with postmenopausal osteoporosis in the Danish National Registry of Patients

BACKGROUND

Osteonecrosis of the jaw (ONJ) is an adverse effect of drugs that suppress bone turnover - for example, drugs used for the treatment of postmenopausal osteoporosis. The Danish National Registry of Patients (DNRP) is potentially valuable for monitoring ONJ and its prognosis; however, no specific code for ONJ exists in the International Classification of Diseases 10th revision (ICD-10), which is currently used in Denmark. Our aim was to estimate the positive predictive value (PPV) of an algorithm to capture ONJ cases in the DNRP among women with postmenopausal osteoporosis.

METHODS

We conducted this cross-sectional validation study in the Central and North Denmark Regions, with approximately 1.8 million inhabitants. In total, 54,956 women with postmenopausal osteoporosis were identified from June 1, 2005 through May 31, 2010. To identify women potentially suffering from ONJ, we applied an algorithm based on ICD-10 codes in the DNRP originating from hospital-based departments of oral and maxillofacial surgery (DOMS). ONJ was adjudicated by chart review and defined by the presence of exposed maxillofacial bone for 8 weeks or more, in the absence of recorded history of craniofacial radiation therapy. We estimated the PPV for the overall algorithm and for each separate ICD-10 code used in the algorithm.

RESULTS

Charts were obtained and reviewed for all 60 women with an ICD-10 code potentially representing ONJ. Nineteen potential ONJ cases were confirmed, corresponding to an overall PPV of 32% (95% confidence interval: 20%-45%).

CONCLUSION

Among women with postmenopausal osteoporosis, only about one-third of the potential ONJ cases identified by our ICD-10 based algorithm were confirmed by medical chart review, despite the restriction to patients treated at DOMS. To capture true ONJ cases among women with postmenopausal osteoporosis, alternative approaches are needed.