MMMarko A. Mychaskiw

Marko A. Mychaskiw

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Marko A. Mychaskiw has a total of 13 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Prevalence of pulmonary arterial hypertension in patients with connective tissue diseases: a systematic review of the literature

    by Xiaoqin Yang, Jack Mardekian, Kafi N. Sanders, Marko A. Mychaskiw, Joseph Thomas

    Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease. Understanding of PAH prevalence remains limited, but PAH has been reported as a frequent complication in connective tissue diseases. This study estimated prevalence of PAH in patients with connective tissue diseases and prevalence of idiopathic PAH using a systematic review of the literature. We searched PubMed through May 19, 2012 for all studies on prevalence of PAH in patients with connective tissue diseases or prevalence of idiopathic PAH. To be included, studies had to be in English, have humans as subjects, and determine prevalence within a time interval of up to 2 years. Studies only investigating pediatric patients were excluded. Pooled prevalence estimates were calculated. Twenty studies were identified in the review. Seventeen of the 20 studies reported prevalence of PAH in connective tissue diseases and three reported prevalence of idiopathic PAH. The pooled prevalence estimate of idiopathic PAH was 12 cases per million population (95 % CI 5 cases per million to 22 cases per million) with estimates ranging from 5.9 cases per million population to 25 cases per million population. The pooled prevalence estimate of PAH in patients with connective tissue diseases was 13 % (95 % CI, 9.18 % to 18.16 %) with reported estimates ranging from 2.8 % to 32 %. Prevalence of PAH in patients with connective tissue diseases was substantially higher than that of idiopathic PAH based on pooled prevalence estimates. Comparisons of PAH prevalence in persons with connective tissue disease and idiopathic PAH using a large observational study would be helpful in better assessing relative prevalence.


  • Open Access

    Changes in healthcare utilization and costs associated with sildenafil therapy for pulmonary arterial hypertension: a retrospective cohort study

    by Ariel Berger, John Edelsberg, Simon Teal, Marko A Mychaskiw, Gerry Oster

    Little is known concerning the degree to which initiation of sildenafil for pulmonary arterial hypertension (PAH) impacts patterns of healthcare utilization and costs. Using a large US health insurance claims database, we identified all patients with evidence of PAH (ICD-9-CM diagnosis codes 416.0, 416.8) who received sildenafil between 1/1/2005 and 9/30/2008. Date of the first-noted prescription for sildenafil was designated the “index date,” and claims data were compiled for all study subjects for 6 months prior to their index date (“pretreatment”) and 6 months thereafter (“follow-up”); patients with incomplete data during either of these periods were excluded. Healthcare utilization and costs were then compared between pretreatment and follow-up for all study subjects. A total of 567 PAH patients were identified who began therapy with sildenafil and met all other study entry criteria. Mean (SD) age was 52 (10) years; 73% were women. Healthcare utilization was largely unchanged between pretreatment and follow-up, the only exceptions being decreases in the mean number of emergency department visits (from 0.7 to 0.5 per patient; p < 0.01) and the percentage of patients hospitalized (from 35% to 29%; p = 0.01). The mean cost of all PAH-related medication was $7139 during pretreatment and $14,095 during follow-up (sildenafil cost during follow-up = $5236); exclusive of PAH-related medications, however, total healthcare costs decreased modestly (from $30,104 to $27,605) (p < 0.01 for all comparisons). The cost of sildenafil therapy may be partially offset by reductions in other healthcare costs.


  • Open Access

    Assessment of measurement properties of peak VO2in children with pulmonary arterial hypertension

    by Joseph C Cappelleri, Lie-Ju Hwang, Jack Mardekian, Marko A Mychaskiw

    The 6-minute walk test evaluates the effect of pharmacologic intervention in adults with pulmonary arterial hypertension (PAH) but, for reasons of compliance or reliability, may not be appropriate for children at all ages. Thus, peak oxygen consumption (VO2, maximal exercise test) was used instead in a pediatric PAH trial (STARTS-1) to evaluate pharmacologic intervention with sildenafil. This was the first large placebo-controlled trial to use the peak VO2 endpoint in this population. Our working hypothesis was that, as with other populations, percentage changes in peak VO2 in pediatric patients with PAH are reliable and are associated with changes in other clinical endpoints.


  • Open Access

    Medication adherence and utilization in patients with schizophrenia or bipolar disorder receiving aripiprazole, quetiapine, or ziprasidone at hospital discharge: A retrospective cohort study

    by Ariel Berger, John Edelsberg, Kafi N Sanders, Jose Ma J Alvir, Marko A Mychaskiw, Gerry Oster

    Schizophrenia and bipolar disorder are chronic debilitating disorders that are often treated with second-generation antipsychotic agents, such as aripiprazole, quetiapine, and ziprasidone. While patients who are hospitalized for schizophrenia and bipolar disorder often receive these agents at discharge, comparatively little information exists on subsequent patterns of pharmacotherapy. Using a database linking hospital admission records to health insurance claims, we identified all patients hospitalized for schizophrenia (ICD-9-CM diagnosis code 295.XX) or bipolar disorder (296.0, 296.1, 296.4-296.89) between January 1, 2001 and September 30, 2008 who received aripiprazole, quetiapine, or ziprasidone at discharge. Patients not continuously enrolled for 6 months before and after hospitalization (“pre-admission” and “follow-up”, respectively) were excluded. We examined patterns of use of these agents during follow-up, including adherence with treatment (using medication possession ratios [MPRs] and cumulative medication gaps [CMGs]) and therapy switching. Analyses were undertaken separately for patients with schizophrenia and bipolar disorder, respectively. We identified a total of 43 patients with schizophrenia, and 84 patients with bipolar disorder. During the 6-month period following hospitalization, patients with schizophrenia received an average of 101 therapy-days with the second-generation antipsychotic agent prescribed at discharge; for patients with bipolar disorder, the corresponding value was 68 therapy-days. Mean MPR at 6 months was 55.1% for schizophrenia patients, and 37.3% for those with bipolar disorder; approximately one-quarter of patients switched to another agent over this period. Medication compliance is poor in patients with schizophrenia or bipolar disorder who initiate treatment with aripiprazole, quetiapine, or ziprasidone at hospital discharge.


  • Open Access

    Magnitude of potentially inappropriate prescribing in Germany among older patients with generalized anxiety disorder

    by Ariel Berger, Marko Mychaskiw, Ellen Dukes, John Edelsberg, Gerry Oster

    Background: Several medications commonly used to treat generalized anxiety disorder (GAD) have been designated "potentially inappropriate" for use in patients aged ≥65 years because their risks may outweigh their potential benefits. The actual extent of use of these agents in clinical practice is unknown, however. Methods: Using a database with information from encounters with general practitioners (GP) in Germany, we identified all patients, aged ≥65 years, with any GP office visits or dispensed prescriptions with a diagnosis of GAD (ICD-10 diagnosis code F41.1) between 10/1/2003 and 9/30/2004 ("GAD patients"). Among GAD-related medications (including benzodiazepines, tricyclic antidepressants [TCAs], selective serotonin reuptake inhibitors, venlafaxine, hydroxyzine, buspirone, pregabalin, and trifluoperazine), long-acting benzodiazepines, selected short-acting benzodiazepines at relatively high dosages, selected TCAs, and hydroxyzine were designated "potentially inappropriate" for use in patients aged ≥ 65 years, based on published criteria. Results: A total of 975 elderly patients with GAD were identified. Mean age was 75 years, and 72% were women; 29% had diagnoses of comorbid depression. Forty percent of study subjects received potentially inappropriate agents – most commonly, bromazepam (10% of all subjects), diazepam (9%), doxepin (7%), amitriptyline (5%), and lorazepam (5%). Twenty-three percent of study subjects received long-acting benzodiazepines, 10% received short-acting benzodiazepines at relatively high doses, and 12% received TCAs designated as potentially inappropriate. Conclusion: GPs in Germany often prescribe medications that have been designated as potentially inappropriate to their elderly patients with GAD – especially those with comorbid depressive disorders. Further research is needed to ascertain whether there are specific subgoups of elderly patients with GAD for whom the benefits of these medications outweigh their risks.