Publications by authors named "Karissa M Johnston"

Objectives: There is increasing interest in expanding the elements of value to be considered when making health policy decisions. To help inform value frameworks, this study quantified preferences for disease attributes in a general public sample and examined which combination of attributes (disease profiles) are considered most important for research and treatment.

Methods: A discrete choice experiment (DCE) was conducted in a US general population sample, recruited through online consumer panels.

View Article and Find Full Text PDF

Background: Patients with asthma use short-acting β-agonists (SABA) to relieve symptoms but SABA alone does not treat underlying inflammation. Thus, over-reliance on SABA may result in poor asthma control and negative health outcomes.

Objective: To describe use of SABA and characterise the relationship with severe exacerbations in the Canadian provinces of Nova Scotia (NS) and Alberta (AB).

View Article and Find Full Text PDF

Objectives: To develop and compare benefit-risk profiles for rimegepant, ubrogepant, and lasmiditan based on a network meta-analysis (NMA) of published clinical trials.

Methods: A fixed-effects Bayesian NMA of randomized controlled trials of lasmiditan, rimegepant, and ubrogepant for the acute treatment of adults with migraine were used to determine risk differences for efficacy and safety outcomes of the 3 treatments compared with pooled placebo. Risk differences were used to calculate number needed to treat (NNT) for pain relief and pain freedom at 2 and 2 to 24 hours and freedom from most bothersome symptoms at 2 hours; and number needed to harm (NNH) for dizziness and nausea, relative to placebo.

View Article and Find Full Text PDF

Objective: To evaluate the costs and benefits associated with the use of abobotulinumtoxinA (aboBoNT-A) and onabotulinumtoxinA (onaBoNT-A) for lower limb spasticity in children, upper and lower limb spasticity in adults, and cervical dystonia in adults.

Methods: This pharmacoeconomic analysis compared aboBoNT-A with onaBoNT-A. A decision tree model with a 1-year time horizon was conducted from a UK National Health Service (NHS) perspective using data from a variety of sources: randomized controlled trials (RCTs), network meta-analyses (NMAs), observational studies, and a physician survey investigating treatment patterns and resource utilization.

View Article and Find Full Text PDF

Access to individual patient data (IPD) can be advantageous when conducting cost-effectiveness analyses or indirect treatment comparisons. While exact times of censoring are often marked on published Kaplan-Meier (KM) curves, an algorithm for reconstructing IPD from such curves that allows for their incorporation is presently unavailable. An algorithm capable of incorporating marked censoring times was developed to reconstruct IPD from KM curves, taking as additional inputs the total patient count and coordinates of the drops in survival.

View Article and Find Full Text PDF

Introduction: Migraine is a debilitating neurological condition, affecting up to 15% of Americans. Recent estimates from a long-term safety study of rimegepant showed evidence of decreased monthly migraine days (MMD) in people with episodic migraine treated with rimegepant 75 mg. The objective of this study was to characterize migraine-specific quality of life version 2.

View Article and Find Full Text PDF

Background: Although the frequency of heart failure makes it among the costliest of illnesses, there are scant Canadian data on annual costs of treatment or the costs as the condition advances. Our objective was to estimate mean prevalence- and incidence-based direct medical costs among older adults discharged alive after a first hospital admission for heart failure.

Methods: We conducted a retrospective cohort study using population-based administrative health databases for Nova Scotia.

View Article and Find Full Text PDF

Although complement inhibition is highly effective, patients with paroxysmal nocturnal hemoglobinuria (PNH) may experience intravascular breakthrough hemolysis (BTH). Underlying causes may include elevated free C5, pregnancy, or non-pregnancy complement-activating conditions (e.g.

View Article and Find Full Text PDF

Objectives: Genomic profiling in oncology is vital for determining eligible patients for mutation-specific targeted therapies. Use of commercial genomic testing has the potential to improve patient outcomes. Economic evaluations of in-house genomic profiling typically only include material costs while external commercial services include many other factors.

View Article and Find Full Text PDF

Aims: To characterize the epidemiology and treatment patterns of adult men (≥40 years) diagnosed with, or treated for, overactive bladder (OAB) and/or benign prostatic hyperplasia (BPH).

Methods: This retrospective observational study used data extracted from the IBM MarketScan Commercial Claims and Encounters database and the Medicare Supplemental Coordination of Benefits database. Men with BPH and/or OAB were identified and observed to assess treatment and diagnostic patterns.

View Article and Find Full Text PDF

Background/objectives: Available metrics for characterizing cumulative anticholinergic exposure over time may not be well suited for use across all US data sources. In this review, the properties of existing anticholinergic scales and measures were evaluated to determine their suitability for implementation in observational studies relying on administrative data.

Methods: A targeted literature review was conducted to identify available anticholinergic scales and measures.

View Article and Find Full Text PDF

Data visualisation techniques are valuable tools for exploring, synthesising and communicating the results of research studies. Advanced data visualisation techniques, including dynamic and interactive visualisations, are just beginning to be used in health economics and outcome research (HEOR). In HEOR, there is the potential to use these techniques both to explore methodological challenges that are central to the design and interpretation of the findings of pharmacoeconomic and outcomes research studies, but also to communicate research findings to various stakeholders.

View Article and Find Full Text PDF

Introduction: The objective was to identify the most commonly used patient-reported outcome (PRO) instruments for overactive bladder (OAB), determine which are the most useful for measuring burden in OAB and characterize the findings of recent studies that have employed PRO instruments to assess OAB symptoms and the effects of treatment.

Methods: A systematic search of OAB literature published between January 2006 and November 2017 using Medline/PubMed and EMBASE databases.

Results: Of 3425 abstracts and 500 full-text articles reviewed, 58 studies (both clinical trials and observational studies) were included in the review.

View Article and Find Full Text PDF

Background: Observational burden of illness studies are used in pharmacoepidemiology to address a variety of objectives, including contextualizing the current treatment setting, identifying important treatment gaps, and providing estimates to parameterize economic models. Methodologies such as retrospective chart review may be utilized in settings for which existing datasets are not available or do not include sufficient clinical detail. While specifying the number of charts to be extracted and/or determining whether the number that can feasibly extracted will be clinically meaningful is an important study design consideration, there is a lack of rigorous methods available for sample size calculation in this setting.

View Article and Find Full Text PDF

Introduction: Urinary symptoms are associated with an increased risk of falls, but few studies have focused on patients with overactive bladder (OAB). This study aimed to synthesize estimates of the risk of falls and fractures in patients with OAB.

Methods: Medline, EMBASE, the Cumulative Index to Nursing and Allied Health Literature, and Scopus were systematically searched for observational studies that focused on patients with OAB.

View Article and Find Full Text PDF

Background: Major depressive disorder (MDD) is a global public health concern. In particular, treatment-resistant depression (TRD) represents a key unmet need in the management of MDD. A systematic review of the epidemiological and economic literature on the burden associated with an increasing number of treatment steps due to TRD/non-response within an MDD episode was performed to quantify the burden of TRD.

View Article and Find Full Text PDF

Objectives: Although brentuximab vedotin (BV) has changed the management of patients with relapsed or refractory Hodgkin lymphoma (RRHL), little information is available on routine clinical practice. We identified treatment patterns and costs of care among RRHL patients in the United States (US) treated with BV.

Methods: A retrospective observational study of adults initiating BV for RRHL from 2011-2015, with ≥6 months of data prior to and following BV initiation, was conducted.

View Article and Find Full Text PDF

Background: The impact of cardiovascular complications on health-related quality-of-life (HRQoL) in type 2 diabetes mellitus has not been clearly established. Using EQ5D utility data from SAVOR-TIMI 53, a large phase IV trial of saxagliptin versus placebo, we quantified the impact of cardiovascular and other major events on HRQoL.

Methods: EQ5D utilities were recorded annually and following myocardial infarction (MI) or stroke.

View Article and Find Full Text PDF

Objective: Treatment options for psoriasis offer trade-offs in terms of efficacy, convenience, and risk of adverse events. We evaluated patients' preferences with respect to benefit-risk in the treatment of psoriasis.

Methods: A discrete choice experiment was conducted in adults from the UK with moderate-to-severe psoriasis using an orthogonal design with 32 hypothetical choice sets.

View Article and Find Full Text PDF

Melanoma presents an important burden worldwide. Until recently, the prognosis for unresectable and metastatic melanoma was poor, with 10% of metastatic melanoma patients surviving for 2 years. The introduction of newer therapies including ipilimumab, vemurafenib, dabrafenib and trametinib improved progression-free survival, with additional benefits anticipated from the forthcoming class of programmed cell death 1 inhibitors.

View Article and Find Full Text PDF

Purpose: Predicting the timing and number of end-stage renal disease (ESRD) cases from a population of individuals with pre-ESRD chronic kidney disease (CKD) has not previously been reported. The objective is to predict the timing and number of cases of ESRD occurring over the lifetime of a cohort of hypothetical CKD patients in the US based on a range of baseline estimated glomerular filtration rate (eGFR) values and varying rates of eGFR decline.

Methods: A three-state Markov model - functioning kidney, ESRD, and death - with an annual cycle length is used to project changes in baseline eGFR on long-term health outcomes in a hypothetical cohort of CKD patients.

View Article and Find Full Text PDF

Background: Preterm birth is a major risk factor for morbidity and mortality among infants worldwide, and imposes considerable burden on health, education and social services, as well as on families and caregivers. Morbidity and mortality resulting from preterm birth is highest among early (< 28 weeks gestational age) and moderate (28-32 weeks) preterm infants, relative to late preterm infants (33-36 weeks). However, substantial societal burden is associated with late prematurity due to the larger number of late preterm infants relative to early and moderate preterm infants.

View Article and Find Full Text PDF

Background: The extent to which a genomic test will be used in practice is affected by factors such as ability of the test to correctly predict response to treatment (i.e. sensitivity and specificity of the test), invasiveness of the testing procedure, test cost, and the probability and severity of side effects associated with treatment.

View Article and Find Full Text PDF

In advanced follicular lymphoma, rituximab is currently used with chemotherapy as induction therapy, and as maintenance monotherapy following induction in previously untreated patients and treatment-experienced relapsed/refractory patients. Herein, the authors characterize the clinical effectiveness, safety and cost-effectiveness of rituximab in follicular lymphoma, based on the literature review. Rituximab has a favorable safety profile and has been shown to improve progression-free survival, with some evidence of improvements to overall survival, particularly for relapsed/refractory patients.

View Article and Find Full Text PDF