Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Gorana Capkun is active.

Publication


Featured researches published by Gorana Capkun.


PLOS ONE | 2014

Relapse rates in patients with multiple sclerosis switching from interferon to fingolimod or glatiramer acetate: a US claims database study.

Niklas Bergvall; Charles Makin; Raquel Lahoz; Neetu Agashivala; Ashish Pradhan; Gorana Capkun; Allison Petrilla; Swapna Karkare; Catherine Balderston McGuiness; Jonathan R. Korn

Background Approximately one-third of patients with multiple sclerosis (MS) are unresponsive to, or intolerant of, interferon (IFN) therapy, prompting a switch to other disease-modifying therapies. Clinical outcomes of switching therapy are unknown. This retrospective study assessed differences in relapse rates among patients with MS switching from IFN to fingolimod or glatiramer acetate (GA) in a real-world setting. Methods US administrative claims data from the PharMetrics Plus™ database were used to identify patients with MS who switched from IFN to fingolimod or GA between October 1, 2010 and March 31, 2012. Patients were matched 1∶1 using propensity scores within strata (number of pre-index relapses) on demographic (e.g. age and gender) and disease (e.g. timing of pre-index relapse, comorbidities and symptoms) characteristics. A claims-based algorithm was used to identify relapses while patients were persistent with therapy over 360 days post-switch. Differences in both the probability of experiencing a relapse and the annualized relapse rate (ARR) while persistent with therapy were assessed. Results The matched sample population contained 264 patients (n = 132 in each cohort). Before switching, 33.3% of patients in both cohorts had experienced at least one relapse. During the post-index persistence period, the proportion of patients with at least one relapse was lower in the fingolimod cohort (12.9%) than in the GA cohort (25.0%), and ARRs were lower with fingolimod (0.19) than with GA (0.51). Patients treated with fingolimod had a 59% lower probability of relapse (odds ratio, 0.41; 95% confidence interval [CI], 0.21–0.80; p = 0.0091) and 62% fewer relapses per year (rate ratio, 0.38; 95% CI, 0.21–0.68; p = 0.0013) compared with those treated with GA. Conclusions In a real-world setting, patients with MS who switched from IFNs to fingolimod were significantly less likely to experience relapses than those who switched to GA.


Journal of Medical Economics | 2014

Persistence with and adherence to fingolimod compared with other disease-modifying therapies for the treatment of multiple sclerosis: a retrospective US claims database analysis

Niklas Bergvall; Allison Petrilla; Swapna Karkare; Raquel Lahoz; Neetu Agashivala; Ashish Pradhan; Gorana Capkun; Charles Makin; Catherine Balderston McGuiness; Jonathan R. Korn

Abstract Objective: Achieving therapeutic goals in multiple sclerosis (MS) requires strict adherence to treatment schedules. This retrospective study analyzed persistence with, and adherence to, fingolimod compared with injectable/infusible disease-modifying therapies (DMTs) in patients with MS. Methods: Patients in the PharMetrics Plus™ US administrative claims database with at least one prescription for, or administration of, fingolimod, glatiramer acetate (GA), interferon (IFN), or natalizumab (index DMT) between October 1, 2010 and September 30, 2011 were included. Patients were naïve to index DMT (no claim in the previous 360 days) and had an MS diagnosis code within 360 days of the first index DMT prescription. Outcomes were persistence, risk of discontinuing index DMT (evaluated by a Cox proportional hazards model), adherence (measured using the medication possession ratio [MPR] and proportion of days covered [PDC] in patients with at least two index DMT prescriptions), and the risk of being non-adherent (MPR <80% and PDC <80%, assessed using a logistic regression model). Results: The study included 3750 patients (fingolimod, n = 889; GA, n = 1233; any IFN, n = 1341; natalizumab, n = 287). Discontinuation rates (fingolimod, 27.9%; GA, 39.5%; IFN, 43.7%; natalizumab, 39.5%; all p < 0.001) and risk of discontinuation were significantly higher (hazard ratios vs fingolimod [95% confidence interval]: GA, 1.75 [1.49–2.07]; IFN, 2.01 [1.71–2.37]; natalizumab, 1.53 [1.22–1.91]) for patients receiving other DMTs compared with fingolimod. The risk of being non-adherent was also lower for patients in the fingolimod cohort than the other treatment cohorts, irrespective of whether non-adherence was defined as MPR <80% (p < 0.05 for all) or PDC <80% (p < 0.05 for GA and IFN). Limitations: As with all studies assessing real-world treatment patterns it is unclear if medications were used as prescribed. Conclusions: In a real-world setting, persistence with, and adherence to, oral fingolimod was higher than for injectable and infusible DMTs.


Multiple sclerosis and related disorders | 2015

Mortality and comorbidities in patients with multiple sclerosis compared with a population without multiple sclerosis: An observational study using the US Department of Defense administrative claims database

Gorana Capkun; Frank Dahlke; Raquel Lahoz; Beth L. Nordstrom; Hugh H. Tilson; Gary Cutter; Dorina Bischof; Alan Moore; Jason C. Simeone; Kathy H. Fraeman; Fabrice Bancken; Yvonne Geissbühler; Michael Wagner; Stanley Cohan

BACKGROUND Data are limited for mortality and comorbidities in patients with multiple sclerosis (MS). OBJECTIVES Compare mortality rates and event rates for comorbidities in MS (n=15,684) and non-MS (n=78,420) cohorts from the US Department of Defense (DoD) database. METHODS Comorbidities and all-cause mortality were assessed using the database. Causes of death (CoDs) were assessed through linkage with the National Death Index. Cohorts were compared using mortality (MRR) and event (ERR) rate ratios. RESULTS All-cause mortality was 2.9-fold higher in the MS versus non-MS cohort (MRR, 95% confidence interval [CI]: 2.9, 2.7-3.2). Frequent CoDs in the MS versus non-MS cohort were infectious diseases (6.2, 4.2-9.4), diseases of the nervous (5.8, 3.7-9.0), respiratory (5.0, 3.9-6.4) and circulatory (2.1, 1.7-2.7) systems and suicide (2.6, 1.3-5.2). Comorbidities including sepsis (ERR, 95% CI: 5.7, 5.1-6.3), ischemic stroke (3.8, 3.5-4.2), attempted suicide (2.4, 1.3-4.5) and ulcerative colitis (2.0, 1.7-2.3), were higher in the MS versus non-MS cohort. The rate of cancers was also higher in the MS versus the non-MS cohort, including lymphoproliferative disorders (2.2, 1.9-2.6) and melanoma (1.7, 1.4-2.0). CONCLUSIONS Rates of mortality and several comorbidities are higher in the MS versus non-MS cohort. Early recognition and management of comorbidities may reduce premature mortality and improve quality of life in patients with MS.


Current Medical Research and Opinion | 2013

Comparative effectiveness of fingolimod versus interferons or glatiramer acetate for relapse rates in multiple sclerosis: a retrospective US claims database analysis

Niklas Bergvall; Charles Makin; Raquel Lahoz; Neetu Agashivala; Ashish Pradhan; Gorana Capkun; Allison Petrilla; Swapna Karkare; Catherine Balderston McGuiness; Jonathan R. Korn

Abstract Objective: Disease-modifying therapies, such as fingolimod, interferon (IFN) and glatiramer acetate (GA), have differing effects on relapse rates in patients with multiple sclerosis (MS), but little is known about the real-world differences in relapse rates with these treatments. This retrospective study assessed relapse rates in patients with active MS initiating fingolimod, IFN or GA therapy in a real-world setting. Methods: Using administrative claims data from the US PharMetrics Plus database, we identified previously treated and untreated patients with MS who initiated fingolimod, IFN or GA treatment between 1 October 2010 and 31 March 2011 and had experienced a relapse in the previous year. A claims-based algorithm was used to identify relapses over the persistence period in patients with 540 days of post-index continuous enrolment. A logistic regression model assessed the probability of having at least one relapse and a generalized linear model estimated differences in annualized relapse rates (ARRs). Results: The study enrolled 525 patients (fingolimod, n = 128; combined IFN/GA cohort, n = 397) of the 31,041 initially identified. Similar findings for fingolimod and IFN/GA were observed for the unadjusted proportion of patients experiencing relapses (31.3% vs. 34.0%, respectively; p = 0.5653) and ARRs (0.50 vs. 0.55, respectively) while persistent to treatment. After adjusting for baseline differences, fingolimod was associated with a 52% reduction in the probability of having a relapse (odds ratio, 0.48; 95% confidence interval [CI], 0.28–0.84; p = 0.0097) and a 50% reduction in ARR (rate ratio, 0.50; 95% CI, 0.34–0.75; p = 0.0006) compared with IFN/GA. Limitations: Identification of relapses is based on the claims in the database rather than on a clinical assessment. Conclusions: In a real-world setting, fingolimod was shown to be associated with significantly lower relapse rates than IFN/GA in patients with MS who had a history of relapses.


Current Medical Research and Opinion | 2015

Expanding the use of administrative claims databases in conducting clinical real-world evidence studies in multiple sclerosis.

Gorana Capkun; Raquel Lahoz; Elisabetta Verdun; Xue Song; Weston Chen; Jonathan R. Korn; Frank Dahlke; Rita Freitas; Kathy H. Fraeman; Jason C. Simeone; Barbara H. Johnson; Beth L. Nordstrom

Abstract Objective: Administrative claims databases provide a wealth of data for assessing the effect of treatments in clinical practice. Our aim was to propose methodology for real-world studies in multiple sclerosis (MS) using these databases. Research design and methods: In three large US administrative claims databases: MarketScan, PharMetrics Plus and Department of Defense (DoD), patients with MS were selected using an algorithm identified in the published literature and refined for accuracy. Algorithms for detecting newly diagnosed (‘incident’) MS cases were also refined and tested. Methodology based on resource and treatment use was developed to differentiate between relapses with and without hospitalization. Results: When various patient selection criteria were applied to the MarketScan database, an algorithm requiring two MS diagnoses at least 30 days apart was identified as the preferred method of selecting patient cohorts. Attempts to detect incident MS cases were confounded by the limited continuous enrollment of patients in these databases. Relapse detection algorithms identified similar proportions of patients in the MarketScan and PharMetrics Plus databases experiencing relapses with (2% in both databases) and without (15–20%) hospitalization in the 1 year follow-up period, providing findings in the range of those in the published literature. Limitation: Additional validation of the algorithms proposed here would increase their credibility. Conclusions: The methods suggested in this study offer a good foundation for performing real-world research in MS using administrative claims databases, potentially allowing evidence from different studies to be compared and combined more systematically than in current research practice.


Current Medical Research and Opinion | 2015

New opportunities of real-world data from clinical routine settings in life-cycle management of drugs: example of an integrative approach in multiple sclerosis

Dietrich Rothenbacher; Gorana Capkun; Hatice Uenal; Hayrettin Tumani; Yvonne Geissbühler; Hugh H. Tilson

Abstract The assessment and demonstration of a positive benefit–risk balance of a drug is a life-long process and includes specific data from preclinical, clinical development and post-launch experience. However, new integrative approaches are needed to enrich evidence from clinical trials and sponsor-initiated observational studies with information from multiple additional sources, including registry information and other existing observational data and, more recently, health-related administrative claims and medical records databases. To illustrate the value of this approach, this paper exemplifies such a cross-package approach to the area of multiple sclerosis, exploring also possible analytic strategies when using these multiple sources of information.


BMC Medical Research Methodology | 2015

Network meta-analysis combining individual patient and aggregate data from a mixture of study designs with an application to pulmonary arterial hypertension

Howard Thom; Gorana Capkun; Annamaria Cerulli; Richard Nixon; Luke Howard

BackgroundNetwork meta-analysis (NMA) is a methodology for indirectly comparing, and strengthening direct comparisons of two or more treatments for the management of disease by combining evidence from multiple studies. It is sometimes not possible to perform treatment comparisons as evidence networks restricted to randomized controlled trials (RCTs) may be disconnected. We propose a Bayesian NMA model that allows to include single-arm, before-and-after, observational studies to complete these disconnected networks. We illustrate the method with an indirect comparison of treatments for pulmonary arterial hypertension (PAH).MethodsOur method uses a random effects model for placebo improvements to include single-arm observational studies into a general NMA. Building on recent research for binary outcomes, we develop a covariate-adjusted continuous-outcome NMA model that combines individual patient data (IPD) and aggregate data from two-arm RCTs with the single-arm observational studies. We apply this model to a complex comparison of therapies for PAH combining IPD from a phase-III RCT of imatinib as add-on therapy for PAH and aggregate data from RCTs and single-arm observational studies, both identified by a systematic review.ResultsThrough the inclusion of observational studies, our method allowed the comparison of imatinib as add-on therapy for PAH with other treatments. This comparison had not been previously possible due to the limited RCT evidence available. However, the credible intervals of our posterior estimates were wide so the overall results were inconclusive. The comparison should be treated as exploratory and should not be used to guide clinical practice.ConclusionsOur method for the inclusion of single-arm observational studies allows the performance of indirect comparisons that had previously not been possible due to incomplete networks composed solely of available RCTs. We also built on many recent innovations to enable researchers to use both aggregate data and IPD. This method could be used in similar situations where treatment comparisons have not been possible due to restrictions to RCT evidence and where a mixture of aggregate data and IPD are available.


BMC Medical Research Methodology | 2014

Indirect comparisons of ranibizumab and dexamethasone in macular oedema secondary to retinal vein occlusion

Howard Thom; Gorana Capkun; Richard Nixon; Alberto Ferreira

BackgroundTwo treatments, ranibizumab and dexamethasone implant, for visual impairment due to macular oedema (ME) secondary to retinal vein occlusion (RVO) have recently been studied in clinical trials. There have been no head to head comparisons of the two treatments, and improvement measured as gain in Best Corrected Visual Acuity (BCVA) was reported using different outcomes thresholds between trials. To overcome these limitations, and inform an economic model, we developed a combination of a multinomial model and an indirect Bayesian comparison model for multinomial outcomes.MethodsOutcomes of change from baseline in BCVA for dexamethasone compatible with those available for ranibizumab, reported by 4 randomised controlled trials, were estimated by fitting a multinomial distribution model to the probability of a patient achieving outcomes in a range of changes from baseline in BCVA (numbers of letters) at month 1. A Bayesian indirect comparison multinomial model was then developed to compare treatments in the Branch RVO (BRVO) and Central RVO (CRVO) populations.ResultsThe multinomial model had excellent fit to the observed results. With the Bayesian indirect comparison, the probabilities of achieving ≥20 letters, with 95% credible intervals, at month 1 in patients with BRVO were 0.191 (0.130, 0.261) with ranibizumab and 0.093 (0.027, 0.213) with dexamethasone. In patients with CRVO, probabilities were 0.133 (0.082, 0.195) (ranibizumab) and 0.063 (0.016, 0.153) (dexamethasone). Probabilities of a gain in ≥10 letters in BRVO patients were 0.500 (0.365, 0.650) v 0.459 (0.248, 0.724) and in CRVO patients 0.459 (0.332, 0.602) v 0.498 (0.263, 0.791) for ranibizumab and dexamethasone treatments respectively. The comparisons also favoured ranibizumab at month 6 although changes to therapies after month 3 may have introduced bias.ConclusionThe newly developed combination of multinomial and indirect Bayesian comparison models indicated a trend for ranibizumab association with a greater percentage of ME patients achieving visual gains than dexamethasone at months 1 and 6 in a common clinical context, although results were not classically significant. The method was a useful tool for comparisons of probability distributions between clinical trials that reported events on different categorical scales and estimates can be used to inform economic models.


Journal of neuromuscular diseases | 2017

A Systematic Review and Meta-Analysis of Prevalence Studies of Sporadic Inclusion Body Myositis

Aoife Callan; Gorana Capkun; Vijayalakshmi Vasanthaprasad; Rita Freitas; Merrilee Needham

BACKGROUND Sporadic Inclusion Body Myositis (sIBM) is a rare and slowly progressive debilitating muscle disease with symptoms generally developing≥50 years of age. OBJECTIVE To conduct a systematic review and meta-analysis of the prevalence of sIBM literature, including a methodological quality assessment of the selected papers. METHODS A systematic search of Medline, Embase, Cochrane Database of Systematic Reviews and major Myositis and Neurological conferences was conducted. Articles reporting prevalence and published in English up to March 2017 were assessed for methodology quality using the Loney quality assessment, Downs & Black score, and the Methodological Evaluation of Observational Research checklists. Meta-analyses using random effects were completed on both general population and≥50 years prevalence estimates. RESULTS 315 articles were retrieved and data were extracted from 10 relevant studies. One study was subsequently excluded due to methodological issues. The meta-prevalence estimate from 9 papers was 24.8/1,000,000 (95% CI: 20.0-29.6). The methodological quality results were consistent across assessment tools with four articles scoring 4 or 5 out of 8 in the Loney assessment. The meta-prevalence of these four articles was 45.6/ 1,000,000 (95% CI: 35.9-55.2). CONCLUSION There was high variability in reported sIBM prevalence estimates and the quality of the studies conducted. Existing evidence suggests an increase of prevalence estimates over time, which may be explained by growing disease awareness, improvements in diagnostic criteria and study methodologies. Further high quality studies are needed to understand if prevalence varies across geographies or ethnicities.


Archive | 2017

Burden of Illness and Healthcare Resource Use in US Patients with sporadic Inclusion Body Myositis

Gorana Capkun; Aoife Callan; Haijun Tian; Zhongyuan Wei Ms; Changgeng Zhao; Neetu Agashivala Ms

We analyzed the burden of illness of sporadic inclusion body myositis (sIBM) patients and the costs to the healthcare system.

Collaboration


Dive into the Gorana Capkun's collaboration.

Researchain Logo
Decentralizing Knowledge