A Systematic Review of Modeling Approaches to Evaluate Treatments for Relapsed Refractory Multiple Myeloma: Critical Review and Considerations for Future Health Economic Models.

BACKGROUND AND OBJECTIVE: Multiple myeloma is a rare incurable hematological cancer in which most patients relapse or become refractory to treatment. This systematic literature review aimed to critically review the existing economic models used in economic evaluations of systemic treatments for relapsed/refractory multiple myeloma and to summarize how the models addressed differences in the line of therapy and exposure to prior treatment. METHODS: Following a pre-approved protocol, literature searches were conducted on 17 February, 2023, in relevant databases for models published since 2014. Additionally, key health technology assessment agency websites were manually searched for models published as part of submission dossiers since 2018. Reported information related to model conceptualization, structure, uncertainty, validation, and transparency were extracted into a pre-defined extraction sheet. RESULTS: In total, 49 models assessing a wide range of interventions across multiple lines of therapy were included. Only five models specific to heavily pre-treated patients and/or those who were refractory to multiple treatment classes were identified. Most models followed a conventional simple methodology, such as partitioned survival (n = 28) or Markov models (n = 9). All included models evaluated specific interventions rather than the whole treatment sequence. Where subsequent therapies were included in the model, these were generally only considered from a cost and resource use perspective. The models generally used overall and progression-free survival as model inputs, although data were often immature. Sensitivity analyses were frequently reported (n = 41) whereas validation was only considered in less than half (n = 19) of the models. CONCLUSIONS: Published economic models in relapsed/refractory multiple myeloma rarely followed an individual patient approach, mainly owing to the higher need for complex data assumptions compared with simpler modeling approaches. As many patients experience disease progression on multiple treatment lines, there is a growing need for modeling complex treatment strategies, leading to more sophisticated approaches in the future. Maintaining transparency, high reporting standards, and thorough analyses of uncertainty are crucial to support these advancements.

Increasing transparency in indirect treatment comparisons: is selecting effect modifiers the missing part of the puzzle? A review of methodological approaches and critical considerations.

Failure to adjust for effect modifiers (EMs) in indirect treatment comparisons (ITCs) can produce biased and uncertain effect estimates. This is particularly important for health technology assessments (HTAs), where the availability of new treatments is based on comparative effectiveness results. Much emphasis has been placed on advancing ITC methods to adjust for EMs, yet whether EMs are appropriately identified for the conduct of ITCs in the first place is unclear. To understand the extent of guidance and requirements for the selection of EMs for ITCs currently available and if and how this guidance is applied in practice, a series of pragmatic reviews of guidance documents from HTA and non-payer organizations, primary published ITC analyses, and prior HTA submissions in two indications (non-small cell lung cancer and psoriasis) was conducted. The reviews showed that current ITC guidance mainly focused on developing analytical methods to adjust for EMs. Some organizations, such as HTA bodies in the UK, France and Germany, recommended the use of literature reviews, expert opinion and statistical methods to identify EMs. No detailed guidance on the selection process or the appropriate literature review approach was found. Similar trends were identified through the database search and review of prior HTA submissions; only few published ITCs and submissions included information on the EM selection process which was either based on findings from the literature, trial subgroup analyses, or clinical input. No reference to a systematic selection approach was found. There is an urgent need to fill the guidance gap identified across the reviews by including a step in ITC guidelines on how EMs should be identified through systematic reviews, formal expert elicitation, and a quantitative assessment of the EM distribution. Researchers and manufacturers are also encouraged to improve transparent reporting and justification of their selection of EMs to allow for an independent review of the set of factors being considered for adjustment. Both will contribute toward reducing bias in the ITC results and ultimately increase confidence in decision-making.

The added value of haemoglobin to height, age, and sex to predict DLCO in subjects with preserved exercise capacity.

BACKGROUND: The single breath diffusion capacity for carbon monoxide (DLCO) captures several aspects of the role of the lung in meeting the metabolic demands of the body. The magnitude of the independent contributors to the DLCO is unknown. The aim of this study was to investigate the factors that independently contribute to the DLCO. OBJECTIVES: The objective was to investigate the impact of height, age, sex and haemoglobin on DLCO, alveolar volume (VA) and carbon monoxide transfer coefficient (KCO). METHODS: Study participants were pre-screened based on normal exercise capacity achieved during an incremental cardio-pulmonary exercise testing (CPET) using cycle ergometry at McMaster University Medical Center between 1988-2012. Participants who had an FEV1>80% predicted, with an FEV1/FVC ≥0.7 and who achieved a maximum power output ≥80% were selected for analysis. In total, 16,298 subjects [61% male, mean height 1.70m (range 1.26-2.07), age 49 yrs (10-94), weight 79 kg (23-190) had DLCO measured while demonstrating normal spirometry and exercise capacity. RESULTS: The DLCO increased exponentially with height, was 15% greater in males, increased with age yearly until 20, then decreased yearly after the age of 35, and was 6% higher per gram of haemoglobin (5.58*Height(m)1.69*1.15 in Males*(1-0.006*Age>35)*(1+0.01*Age<20) *(1+0.06*Hb gm/dl), (r = 0.76). CONCLUSION: Height, age, sex, and haemoglobin all have independent influence on the DLCO in subjects with normal spirometry and preserved exercise capacity.

Reconstructing the value puzzle in health technology assessment: a pragmatic review to determine which modelling methods can account for additional value elements.

Health technology assessment (HTA) has traditionally relied on cost-effectiveness analysis (CEA) as a cornerstone of evaluation of new therapies, assessing the clinical validity and utility, the efficacy, and the cost-effectiveness of new interventions. The current format of cost-effectiveness analysis, however, does not allow for inclusion of more holistic aspects of health and, therefore, value elements for new technologies such as the impact on patients and society beyond its pure clinical and economic value. This study aimed to review the recent modelling attempts to expand the traditional cost-effectiveness analysis approach by incorporating additional elements of value in health technology assessment. A pragmatic literature review was conducted for articles published between 2012 and 2022 reporting cost-effectiveness analysis including value aspects beyond the clinical and cost-effectiveness estimates; searches identified 13 articles that were eligible for inclusion. These expanded modelling approaches mainly focused on integrating the impact of societal values and health equity in cost-effectiveness analysis, both of which were championed as important aspects of health technology assessment that should be incorporated into future technology assessments. The reviewed cost-effectiveness analysis methods included modification of the current cost-effectiveness analysis methodology (distributional cost-effectiveness analysis, augmented cost-effectiveness analysis, extended cost-effectiveness analysis) or the use of multi-criteria decision analysis. Of these approaches, augmented cost-effectiveness analysis appears to have the most potential by expanding traditional aspects of value, as it uses techniques already familiar to health technology assessment agencies but also allows space for incorporation of qualitative aspects of a product's value. This review showcases that methods to unravel additional value elements for technology assessment exist, therefore, patient access to promising technologies can be improved by moving the discussion from "if" to "how" additional value elements can inform decision-making.

Prognostic Factors of COVID-19: An Umbrella Review Endorsed by the International Society for Pharmacoepidemiology.

During the coronavirus disease 2019 (COVID-19) pandemic, the urgency for updated evidence to inform public health and clinical care placed systematic literature reviews (SLRs) at the cornerstone of research. We aimed to summarize evidence on prognostic factors for COVID-19 outcomes through published SLRs and to critically assess quality elements in the findings' interpretation. An umbrella review was conducted via electronic databases from January 2020 to April 2022. All SLRs (and meta-analyses) in English were considered. Data screening and extraction were conducted by two independent reviewers. AMSTAR 2 tool was used to assess SLR quality. The study was registered with PROSPERO (CRD4202232576). Out of 4,564 publications, 171 SLRs were included of which 3 were umbrella reviews. Our primary analysis included 35 SLRs published in 2022, which incorporated studies since the beginning of the pandemic. Consistent findings showed that, for adults, older age, obesity, heart disease, diabetes, and cancer were more strongly predictive of risk of hospitalization, intensive care unit admission, and mortality due to COVID-19. Male sex was associated with higher risk of short-term adverse outcomes, but female sex was associated with higher risk of long COVID. For children, socioeconomic determinants that may unravel COVID-19 disparities were rarely reported. This review highlights key prognostic factors of COVID-19, which can help clinicians and health officers identify high-risk groups for optimal care. Findings can also help optimize confounding adjustment and patient phenotyping in comparative effectiveness research. A living SLR approach may facilitate dissemination of new findings. This paper is endorsed by the International Society for Pharmacoepidemiology.

Ponatinib vs. Imatinib as Frontline Treatment for Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Matching Adjusted Indirect Comparison.

INTRODUCTION: Efficacy of ponatinib-based treatment for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) has not been compared to imatinib-based treatments in head-to-head clinical trials. We evaluated its efficacy versus imatinib-based regimens using a matching adjusted indirect comparison. METHODS: Two ponatinib studies were used: the phase 2 MDACC study of ponatinib + hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, and dexamethasone) in adult patients and the phase 2 GIMEMA LAL1811 study of ponatinib + steroids in patients > 60 years/unfit for intensive chemotherapy and stem cell transplant. Studies on imatinib as first-line treatment in adults with Ph + ALL were identified using a systematic literature search. Population adjustment was based on the prognostic factors and effect modifiers identified by clinical experts. Hazard ratios (HRs) were calculated for overall survival (OS) and odds ratios (ORs) for complete molecular response (CMR). RESULTS: The systematic literature search identified two studies (GRAAPH-2005 and NCT00038610) reporting the efficacy of first-line imatinib + hyper-CVAD and one study reporting the efficacy of first-line imatinib monotherapy induction + imatinib-based consolidation (CSI57ADE10). Ponatinib + hyper-CVAD prolonged OS and gave a higher CMR rate than imatinib + hyper-CVAD. The adjusted HR [95% confidence interval (CI)] for OS was 0.35 (0.17-0.74) for MDACC vs. GRAAPH-2005 and 0.35 (0.18-0.70) for MDACC vs. NCT00038610; the adjusted OR (95% CI) for CMR was 12.11 (3.77-38.87) for MDACC vs. GRAAPH-2005 and 5.65 (2.02-15.76) for MDACC vs. NCT00038610. Ponatinib + steroids prolonged OS and gave a higher CMR rate than imatinib monotherapy induction + imatinib-containing consolidation. The adjusted HR (95% CI) for OS was 0.24 (0.09-0.64) and the adjusted OR (95% CI) for CMR was 6.20 (1.60-24.00) for GIMEMA LAL1811 vs. CSI57ADE10. CONCLUSION: In adults with newly diagnosed Ph + ALL, first-line treatment with ponatinib was associated with better outcomes than first-line treatment with imatinib.

Efficacy of abobotulinumtoxinA versus onabotulinumtoxinA for the treatment of refractory neurogenic detrusor overactivity: a systematic review and indirect treatment comparison.

AIMS: To compare the efficacy and safety of abobotulinumtoxinA (aboBoNT-A) and onabotulinumtoxinA (onaBoNT-A) for the treatment of refractory neurogenic detrusor overactivity (NDO), using an indirect treatment comparison (ITC). MATERIALS AND METHODS: A systematic literature review was used to identify randomized controlled trials (RCTs) that evaluated botulinum toxin type A for the treatment of refractory NDO. Treatments were compared using a Bucher ITC approach. Efficacy outcomes were reduction in number of weekly urinary incontinence (UI) episodes at 6, 12, and 24 weeks of follow-up. The safety outcome was the proportion of patients with treatment-emergent urinary tract infections (TE-UTIs) during follow-up. Subgroup/sensitivity analyses were performed to investigate the impact of heterogeneity. RESULTS: Fifteen studies of botulinum toxin type A were identified. Among these, onaBoNT-A 200 U was the only botulinum toxin type A considered an appropriate comparator for aboBoNT-A 600 U and 800 U. As such, six RCTs that evaluated onaBoNT-A or aboBoNT-A were included in the ITC. In base-case analyses, there were no statistically significant differences between aboBoNT-A and onaBoNT-A in terms of UI episodes or TE-UTIs. Numerically, the trend favored aboBoNT-A (either dose) for all endpoints and time points. At 12 and 24 weeks, the difference in reduction of UI episodes per week was considered clinically relevant when comparing aboBoNT-A 800 U with onaBoNT-A 200 U, but not when comparing the lower dose of aboBoNT-A (600 U) with onaBoNT-A 200 U. Results from subgroup/sensitivity analyses were consistent with the base case. LIMITATIONS: Heterogeneity across studies was observed; however, strong consistency of trends across analyses suggests the impact of heterogeneity is low. CONCLUSIONS: There may be potential advantages of aboBoNT-A over onaBoNT-A, in terms of UI reduction, in patients with refractory NDO. More confirmatory studies are needed owing to the sparsity of current evidence.

Neurogenic detrusor overactivity (NDO) is a condition in which the bladder muscle wall is overactive and does not function normally. This can lead to urinary incontinence (i.e. accidental leakage of urine). NDO may also cause urinary tract infections and upper urinary tract damage if it is left untreated or if treatment does not work (i.e. refractory NDO).Botulinum toxin is a treatment that relaxes muscles in patients with refractory NDO, so they have less chance of experiencing urinary incontinence. This study used results from clinical trials to compare two types of botulinum toxin ­ abobotulinumtoxinA (aboBoNT-A) and onabotulinumtoxinA (onaBoNT-A) ­ to see if one works better than the other.Clinical trials are experiments to assess how well treatments work by giving different treatments to different patients and observing the results. When there is no clinical trial that compares the two treatments you are interested in, it is possible to combine results from a number of different clinical trials instead. This is known as an indirect treatment comparison.We used an indirect treatment comparison to compare aboBoNT-A and onaBoNT-A for the treatment of refractory NDO. Results showed that aboBoNT-A may be more effective than onaBoNT-A in reducing the frequency of urinary incontinence episodes. On average, patients treated with aboBoNT-A had at least three fewer episodes of urinary incontinence per week than those treated with onaBoNT-A. These results suggest that patients treated with aboBoNT-A could have a better quality of life than those treated with onaBoNT-A.

Recurrence Rates and Pharmacological Treatment for Hemorrhoidal Disease: A Systematic Review.

INTRODUCTION: Hemorrhoidal disease (HD) is characterized by prolapse of the inflamed and bleeding vascular tissues of the anal canal. Although HD is associated with a high recurrence rate, there is a lack of understanding around interventions that can reduce recurrence and improve outcomes for patients. As such, a systematic literature review (SLR) was conducted to summarize evidence on epidemiology, recurrence, and efficacy of interventions in HD. METHODS: Real-world evidence (RWE) studies evaluating the incidence, prevalence, or recurrence of HD, as well as SLRs including a meta-analytic component reporting on the efficacy of systemic or topical pharmacological treatments for adults with HD, were included. Systematic searches were conducted in MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Database of Systematic Reviews. RESULTS: The SLR identified 44 eligible publications. Consistent data were limited on the epidemiology of HD or HD recurrence. Specifically, incidence and prevalence reported across geographies were impacted by differences in data collection. Reported risk factors for HD were sedentary behavior, constipation, male gender, and age. Twenty-three RWE studies and one meta-analysis reported HD recurrence rates ranging from 0 to 56.5% following surgery or phlebotonics, with most (n = 19) reporting rates of 20% or less. In addition to time since treatment, risk factors for recurring disease were similar to those for HD in general. With respect to treatment, micronized purified flavonoid fractions significantly improved the main symptoms of HD compared to other pharmacological treatments. CONCLUSION: The SLRs did not identify any RWE studies reporting recurrence in patients receiving systemic or topical treatments, highlighting the need for future research in this area. Further, more studies are needed to understand the optimum duration of medical treatment to prevent recurrence.

Patients with hemorrhoidal disease (HD) can experience recurring disease following a period of improvement or remission. It is not well established how often this might happen, who is at greatest risk, or which treatments can reduce this risk. In this study, a systematic literature review (SLR) was conducted to summarize evidence on the occurrence and recurrence of HD, as well as treatment effectiveness. Several literature databases were searched for articles that described real-world evidence (RWE) studies reporting the epidemiology or recurrence of HD as well as published SLRs that combined the results of multiple studies (meta-analyses) on treatment for adults with HD. Forty of 2037 articles identified by the search were considered relevant, and four others identified by clinicians were also included (total = 44; 39 RWE, 5 meta-analyses). Review of the RWE articles revealed that HD epidemiology was determined differently between studies. Only 23 reported recurrence rates (up to 56.5%) after surgery or treatment with phlebotonic drugs (drugs that improve blood flow in veins). Most (19/23) reported recurrence rates of 20% or less. Risk factors for recurrence were similar to usual HD risk factors (e.g., constipation, male gender, age) in addition to time since treatment. Phlebotonic agents, including those made from plant extracts (micronized purified flavonoid fractions, MPFFs) improved hemorrhoidal symptoms compared with placebo or no treatment. In one meta-analysis, MPFF was the only phlebotonic to significantly reduce recurrence risk versus no treatment or placebo. Overall, more research is needed to compare treatments and determine optimal treatment duration to prevent recurrence. Author-narrated video abstract.

AbobotulinumtoxinA Doses in Upper and Lower Limb Spasticity: A Systematic Literature Review.

Disabling limb spasticity can result from stroke, traumatic brain injury or other disorders causing upper motor neuron lesions such as multiple sclerosis. Clinical studies have shown that abobotulinumtoxinA (AboBoNT-A) therapy reduces upper and lower limb spasticity in adults. However, physicians may administer potentially inadequate doses, given the lack of consensus on adjusting dose according to muscle volume, the wide dose ranges in the summary of product characteristics or cited in the published literature, and/or the high quantity of toxin available for injection. Against this background, a systematic literature review based on searches of MEDLINE and Embase (via Ovid SP) and three relevant conferences (2018 to 2020) was conducted in November 2020 to examine AboBoNT-A doses given to adults for upper or lower limb muscles affected by spasticity of any etiology in clinical and real-world evidence studies. From the 1781 unique records identified from the electronic databases and conference proceedings screened, 49 unique studies represented across 56 publications (53 full-text articles, 3 conference abstracts) were eligible for inclusion. Evidence from these studies suggested that AboBoNT-A dose given per muscle in clinical practice varies considerably, with only a slight trend toward a relationship between dose and muscle volume. Expert-based consensus is needed to inform recommendations for standardizing AboBoNT-A treatment initiation doses based on muscle volume.

Efficacy of Bimekizumab and Other Biologics in Moderate to Severe Plaque Psoriasis: A Systematic Literature Review and a Network Meta-Analysis.

INTRODUCTION: Biologic treatments are increasingly being used in the management of moderate to severe plaque psoriasis (PSO). Bimekizumab is a selective inhibitor of both interleukin (IL)-17A and IL-17F approved for the treatment of moderate to severe PSO. Although bimekizumab trials provide comparisons to secukinumab, adalimumab and ustekinumab, there are no further head-to-head comparisons of bimekizumab to other biologics. This network meta-analysis (NMA) aimed to compare the short-term efficacy of bimekizumab versus other biologic systemic therapies for moderate to severe PSO. METHODS: A systematic literature review was conducted to identify randomised controlled trials (RCTs) in patients with moderate to severe PSO. MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Database of Systematic Reviews and PsycINFO were searched on July 1, 2020. An enhanced multinomial Bayesian NMA model was used to evaluate the comparative efficacy in 50%, 75%, 90% and 100% improvement from baseline Psoriasis Area and Severity Index (PASI 50/75/90/100) at 10-16 weeks. The model was also adjusted for baseline risk, given the variable placebo responses across the trials. RESULTS: Eighty-six RCTs (including 34,476 patients) were included in the NMA. IL-17 and IL-23 inhibitors were the most effective treatments across all PASI levels. At 10-16 weeks, bimekizumab had the highest probability of achieving PASI 75 (92.3%), PASI 90 (84.0%) and PASI 100 (57.8%). Bimekizumab demonstrated statistical superiority over all biologics in achieving PASI 90 and PASI 100 thresholds. For PASI 75, the benefit of bimekizumab was statistically significant compared to all other treatments except risankizumab and ixekizumab. CONCLUSION: This analysis demonstrated that IL-17 and IL-23 inhibitors were highly effective in achieving short-term improvement among patients with moderate to severe PSO. Patients receiving bimekizumab were significantly more likely to achieve PASI 90 or PASI 100 within 10-16 weeks of the first injection than all other biologics.

Pharmacological treatment for chronic venous disease: an umbrella review of systematic reviews.

INTRODUCTION: Chronic venous disease is a persistent venous drainage alteration caused by valvular incompetence and/or outflow obstruction. Disease management includes a variety of treatments, whose evidence and clinical performance in the mid-long term are variable. The objective of this umbrella review was to summarize efficacy data for pharmacological treatments including venoactive drugs from previously published reviews that included a meta-analytic component. EVIDENCE ACQUISITION: Systematic database searches were conducted via Ovid SP on 13 August 2019, covering MEDLINE, Embase, and the Cochrane Database of Systematic Reviews. Reviews that included a meta-analytic component of four or more clinical trials or observational studies reporting on the efficacy of systemic or topical pharmacological treatments for adults with chronic venous disease published since 2010 were eligible for inclusion. EVIDENCE SYNTHESIS: Eleven publications were included in this umbrella review. Change in ankle circumference was the most commonly reported outcome. Overall, several systemic treatments had significant effects compared with placebo on multiple efficacy outcomes, including measures of edema and pain. Out of them, Micronized Purified Flavonoid Fraction had the most comprehensive evidence of effectiveness on main symptoms and signs and on improving quality of life throughout chronic venous disease stages. CONCLUSIONS: Systemic pharmacotherapies represent a valuable therapeutic option in CVD management. As a result of this umbrella review, several gaps were identified with respect to research topics that warrant further investigation, particularly in the category of topical medications.

Modeling Challenges in Cost-Effectiveness Analysis of First-Line Immuno-Oncology Therapies in Non-small Cell Lung Cancer: A Systematic Literature Review.

INTRODUCTION: The introduction of immuno-oncology (IO) therapies has changed the treatment landscape of non-small cell lung cancer (NSCLC). Numerous cost-effectiveness analyses (CEAs) and technology appraisals (TAs) evaluating IO therapies have been recently published. OBJECTIVE: We reviewed economic models of first-line (1L) IO therapies for previously untreated advanced or metastatic NSCLC to identify methodological challenges associated with modeling cost effectiveness from published literature and TAs and to make recommendations for future CEAs in this disease area. METHODS: A systematic literature review was conducted following Cochrane and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We searched MEDLINE, Embase, EconLit (January 2009-January 2020), and select conferences (since 2016) for CEAs of 1L IO treatments in patients with recurrent or metastatic, epidermal growth factor receptor (EGFR)/anaplastic lymphoma kinase (ALK) mutation-negative NSCLC, published in English. TAs from England, Scotland, Canada, Australia, Germany, and France were also examined. Two reviewers screened the results and extracted the data. The quality of the CEAs was described using the Drummond checklist. RESULTS: In total, 46 records reporting on 38 unique models met protocol-defined criteria and were included. Five models adjusted for treatment switching or crossover in base-case analyses, and the remainder considered treatment switching or crossover to represent clinical practice and made no adjustment. Seven models used external real-world data for survival modeling or extrapolation validation. Six models that assumed long-term treatment benefit stopped at 3 or 5 years after initiation. Seven models used the observed time-on-treatment distribution from the trial, and eight used progression-free survival for treatment duration. All models compared one or more IO monotherapies or combination therapies with chemotherapy. Only one study directly compared different IO agents but did not consider the concordance issue across programmed death-ligand 1 (PD-L1) testing methods. Utilities were modeled by health state in 12 models, four applied a time-to-death approach, and ten explored both. None applied cure models. CONCLUSION: Variations in methodological challenges were seen across studies. Previous models took approaches that were followed in subsequent models, such as a 2-year stopping rule of IO duration or treatment-effect waning. Challenges such as heterogeneity in PD-L1 testing and survival extrapolation and validation using real-world data should be further considered for future models in advanced or metastatic NSCLC.

Epidemiology of Clonal Pseudomonas aeruginosa Infection in a Canadian Cystic Fibrosis Population.

RATIONALE: The extent of the genetic relatedness among Pseudomonas aeruginosa isolates and its impact on clinical outcomes in the cystic fibrosis (CF) population is poorly understood. OBJECTIVES: The objectives of this study were to determine the prevalence of clonal P. aeruginosa infection in Canada and to associate P. aeruginosa genotypes with clinical outcomes. METHODS: This was an observational study of adult and pediatric patients with CF across Canada. Isolates were typed using multilocus sequence typing. A clone was defined as sharing at least six of seven alleles. Genotyping results were associated with clinical outcomes, including forced expiratory volume in 1 second, body mass index, rate of pulmonary exacerbation, and death/transplant. RESULTS: A total of 1,537 P. aeruginosa isolates were genotyped to 403 unique sequence types (STs) in 402 individuals with CF. Although 39% of STs were shared, most were shared only among a small number of subjects, and the majority (79%) of the genetic diversity in P. aeruginosa isolates was observed between patients. There were no significant differences in clinical outcomes according to genotype. However, patients with a dynamic, changing ST infection pattern had both a steeper decline in forced expiratory volume in 1 second (-2.9% predicted change/yr, 95% confidence interval [CI] = -3.8 to -1.9 compared with 0.4, 95% CI = -0.3 to 1.0; P < 0.001) and body mass index (-1.0 percentile change/yr, 95% CI = -1.6 to -0.3 compared with -0.1, 95% CI = -0.7 to 0.5; P = 0.047) than those with a stable infection with the same ST. CONCLUSIONS: There was no widespread sharing of dominant clones in our CF population, and the majority of the genetic diversity in P. aeruginosa was observed between patients. Changing genotypes over time within an individual was associated with worse clinical outcomes.

Prediction of clinical peanut allergy status among children in Hamilton, Ontario using chart review data collected during 2012-2015.

BACKGROUND: Peanut sensitization does not necessarily indicate clinical peanut allergy, and uncertainty as to whether or not there is true peanut allergy can lead to increased anxiety and decreased quality of life for patients and their families. The gold standard for diagnosing clinical peanut allergy is the oral food challenge, but this method is time-consuming and can cause severe allergic reactions. It would therefore be beneficial to develop a tool for predicting clinical peanut allergy in peanut-sensitized individuals whose peanut allergy status is unknown so as to better determine who requires an oral food challenge for diagnosis. METHODS: Two separate studies were conducted. In Study 1, we recruited 100 participants from the allergy clinic at McMaster University and community allergy outpatient clinics in the greater Hamilton area. We examined 18 different variables from participants and used univariate and multivariable logistic regression analysis to determine how well these variables, singly and in combination, were able to predict clinical peanut allergy status. In Study 2, we conducted a retrospective chart review of a second cohort of 194 participants to investigate the reproducibility of our findings. This was a matched case-control study where 97 peanut-allergic participants were gender- and age-matched to 97 non-allergic control participants. RESULTS: Peanut skin prick test wheal size was the best predictor of clinical peanut allergy in both study cohorts. For every 1 mm increase in wheal size, the odds ratio of an individual having clinical peanut allergy was 2.36 in our first cohort and 4.85 in our second cohort. No other variable approached the predictive power of wheal size. CONCLUSIONS: Peanut skin prick test wheal size is a robust predictor of clinical peanut reactivity. The findings of this study may be useful in guiding clinician decision-making regarding peanut allergy diagnostics.

The association between platelet transfusions and bleeding in critically ill patients with thrombocytopenia.

BACKGROUND: Platelet transfusions are commonly used to treat critically ill patients with thrombocytopenia. Whether platelet transfusions are associated with a reduction in the risk of major bleeding is unknown. PATIENTS/METHODS: Observational cohort study nested in a previous multicenter, randomized thromboprophylaxis trial in the intensive care unit (ICU). The objective was to evaluate the association between platelet transfusions and adjudicated major bleeding events. Platelet transfusion episodes were reviewed for timing of administration, product type, and dose. Major bleeding with and without platelet transfusions was adjusted for severity of thrombocytopenia, use of anti-platelet agents, surgery and other covariates. Secondary outcomes were thrombosis, death in ICU and platelet count increment. RESULTS: Among 2,256 patients, 71 (3.1%) received 190 platelet transfusions. Of those, 121 (63.7%) were administered to 54 non-bleeding, thrombocytopenic patients. Adjusted rates of major bleeding were not statistically different with or without the administration of platelet transfusions (hazard ratio for transfused patients 0.85; 95% confidence interval, 0.42-1.72). We did not find a significant association between platelet transfusion use and thrombosis or death in ICU in adjusted analyses. Thrombocytopenia, anemia, major or minor bleeding and use of anticoagulants were associated with platelet transfusion administration. The median post-transfusion platelet count increment was 20×109/L at 3.5 hours post-transfusion. CONCLUSIONS: Rates of major bleeding were not different for patients who did and did not receive platelet transfusions. Inferences were limited by the small number of transfused patients. Clinical trials are needed to better investigate the potential hemostatic benefit and potential harms of platelet transfusions for this high-risk population.