The validity, reliability and minimal clinically important difference of the patient specific functional scale in snake envenomation

The BRAVO Clinical Study Protocol: Oral Varespladib for Inhibition of Secretory Phospholipase A2 in the Treatment of Snakebite Envenoming

INTRODUCTION

Snakebite is an urgent, unmet global medical need causing significant morbidity and mortality worldwide. Varespladib is a potent inhibitor of venom secretory phospholipase A2 (sPLA2) that can be administered orally via its prodrug, varespladib-methyl. Extensive preclinical data support clinical evaluation of varespladib as a treatment for snakebite envenoming (SBE). The protocol reported here was designed to evaluate varespladib-methyl for SBE from any snake species in multiple geographies.

METHODS AND ANALYSIS

BRAVO (Broad-spectrum Rapid Antidote: Varespladib Oral for snakebite) is a multicenter, randomized, double-blind, placebo-controlled, phase 2 study to evaluate the safety, tolerability, and efficacy of oral varespladib-methyl plus standard of care (SoC) vs. SoC plus placebo in patients presenting with acute SBE by any venomous snake species. Male and female patients 5 years of age and older who meet eligibility criteria will be randomly assigned 1:1 to varespladib-methyl or placebo. The primary outcome is the Snakebite Severity Score (SSS) that has been modified for international use. This composite outcome is based on the sum of the pulmonary, cardiovascular, nervous, hematologic, and renal systems components of the updated SSS.

ETHICS AND DISSEMINATION

This protocol was submitted to regulatory authorities in India and the US. A Clinical Trial No Objection Certificate from the India Central Drugs Standard Control Organisation, Drug Controller General-India, and a Notice to Proceed from the US Food and Drug Administration have been obtained. The study protocol was approved by properly constituted, valid institutional review boards or ethics committees at each study site. This study is being conducted in compliance with the April 1996 ICH Guidance for Industry GCP E6, the Integrated Addendum to ICH E6 (R2) of November 2016, and the applicable regulations of the country in which the study is conducted. The trial is registered on Clinical trials.gov, NCT#04996264 and Clinical Trials Registry-India, 2021/07/045079 000062.

Outcomes in intervention research on snakebite envenomation: a systematic review

INTRODUCTION

A core outcome set (COS) is a minimal list of consensus outcomes that should be used in all intervention research in a specific domain. COS enhance the ability to undertake meaningful comparisons and to understand the benefits or harms of different treatments. A first step in developing a COS is to identify outcomes that have been used previously. We did this global systematic review to provide the foundation for development of a region-specific COS for snakebite envenomation.  Methods: We searched 15 electronic databases, eight trial registries, and reference lists of included studies to identify reports of relevant trials, protocols, registry records and systematic reviews. We extracted verbatim data on outcomes, their definitions, measures, and time-points. Outcomes were classified as per an existing outcome taxonomy, and we identified unique outcomes based on similarities in the definition and measurement of the verbatim outcomes.

RESULTS

We included 107 records for 97 studies which met our inclusion criteria. These reported 538 outcomes, with a wide variety of outcome measures, definitions, and time points for measurement. We consolidated these into 88 unique outcomes, which we classified into core areas of mortality (1, 1.14 %), life impact (6, 6.82%), resource use (15, 17.05%), adverse events (7, 7.95%), physiological/clinical (51, 57.95%), and composite (8, 9.09%) outcomes. The types of outcomes varied by the type of intervention, and by geographic region. Only 15 of the 97 trials (17.04%) listed Patient Related Outcome Measures (PROMS).

CONCLUSION

Trials evaluating interventions for snakebite demonstrate heterogeneity on outcomes and often omit important information related to outcome measurement (definitions, instruments, and time points). Developing high quality, region-specific COS for snakebite could inform the design of future trials and improve outcome reporting. Measurement of PROMS, resource use and life impact outcomes in trials on snakebite remains a gap.

Measurement Properties of the Patient-Specific Functional Scale and Its Current Uses: An Updated Systematic Review of 57 Studies Using COSMIN Guidelines

OBJECTIVE

To systematically review measurement properties, including acceptability, feasibility, and interpretability, and current uses of the Patient-Specific Functional Scale (PSFS).

DESIGN

Systematic review of a patient-reported outcome measure using the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) guidelines.

LITERATURE SEARCH

We searched 11 databases from January 2010 to July 2020 for articles on measurement properties or use of PSFS.

STUDY SELECTION CRITERIA

Published primary articles without language restrictions.

DATA SYNTHESIS

Two independent reviewers screened all records, extracted data, and performed risk of bias assessments using COSMIN guidelines. We qualitatively synthesized findings for each measurement property in musculoskeletal and nonmusculoskeletal conditions, and 2 reviewers independently performed Grading of Recommendations Assessment, Development and Evaluation assessments. This study was preregistered with the Open Science Framework (https://doi.org/10.17605/OSF.IO/42UZT).

RESULTS

Of the 985 articles screened, we included 57 articles on measurement properties and 255 articles on the use of PSFS. The PSFS had sufficient test-retest reliability in musculoskeletal (22 studies, 845 participants, low-to-moderate certainty) and nonmusculoskeletal conditions (6 studies, 197 participants, very low certainty), insufficient construct validity as a measure of physical function (21 studies, 2 945 participants, low-to-moderate certainty), and sufficient responsiveness (32 studies, 13 770 participants, moderate-to-high certainty). The standard error of measurement ranged from 0.35 to 1.5. The PSFS was used in 87 unique health conditions, some without prior evidence of validity.

CONCLUSION

The PSFS is an easy-to-use, reliable, and responsive scale in numerous musculoskeletal conditions, but the construct validity of PSFS remains uncertain. Further study of the measurement properties of the PSFS in nonmusculoskeletal conditions is necessary before clinical use. J Orthop Sports Phys Ther 2022;52(5):262-275. Epub: 05 Feb 2022. doi:10.2519/jospt.2022.10727.

A simple mortality risk prediction score for viper envenoming in India (VENOMS): A model development and validation study

BACKGROUND

Snakebite is a neglected problem with a high mortality in India. There are no simple clinical prognostic tools which can predict mortality in viper envenomings. We aimed to develop and validate a mortality-risk prediction score for patients of viper envenoming from Southern India.

METHODS

We used clinical predictors from a prospective cohort of 248 patients with syndromic diagnosis of viper envenoming and had a positive 20-minute whole blood clotting test (WBCT 20) from a tertiary-care hospital in Puducherry, India. We applied multivariable logistic regression with backward elimination approach. External validation of this score was done among 140 patients from the same centre and its performance was assessed with concordance statistic and calibration plots.

FINDINGS

The final model termed VENOMS from the term "Viper ENvenOming Mortality Score included 7 admission clinical parameters (recorded in the first 48 hours after bite): presence of overt bleeding manifestations, presence of capillary leak syndrome, haemoglobin <10 g/dL, bite to antivenom administration time > 6.5 h, systolic blood pressure < 100 mm Hg, urine output <20 mL/h in 24 h and female gender. The lowest possible VENOMS score of 0 predicted an in-hospital mortality risk of 0.06% while highest score of 12 predicted a mortality of 99.1%. The model had a concordance statistic of 0·86 (95% CI 0·79-0·94) in the validation cohort. Calibration plots indicated good agreement of predicted and observed outcomes.

CONCLUSIONS

The VENOMS score is a good predictor of the mortality in viper envenoming in southern India where Russell's viper envenoming burden is high. The score may have potential applications in triaging patients and guiding management after further validation.

Contextualizing the Impact of Snakebite Envenoming on Patients: A Qualitative Content Analysis of Patient-Specific Functional Scale Activities Using the International Classification of Functioning, Disability and Health

To categorize the Patient-specific Functional Scale (PSFS) activities in snakebite envenoming (SBE) using the International Classification of Function (ICF) model in order to describe the impact of SBE on patients’ activities and daily lives and to develop a theoretical SBE model of functioning, we performed a post-hoc analysis of two multi-center, prospective studies, conducted at 14 clinical sites in the United States with consecutive SBE patients presenting to the emergency department. Qualitative content analysis and natural language processing were used to categorize activities reported in the PSFS using the ICF model. Our sample included 93 patients. The mean age was 43.0 (SD 17.9) years, most had lower extremity injuries (59%). A total of 99 unique activities representing eight domains came within the Activity and Participation component of the ICF model, with the majority in the Mobility and General Tasks and Demands domains. The main concerns of SBE patients are the ability to perform daily activities and to engage within their social environment. Applying the ICF model to SBE can facilitate the creation of a patient-centered treatment approach, moving beyond body-structural impairments towards a function-based treatment approach and facilitate early integration of rehabilitation services.

Clinical outcomes and outcome measurement tools reported in randomised controlled trials of treatment for snakebite envenoming: A systematic review

BACKGROUND

Snakebite is a priority neglected tropical disease and causes a range of complications that vary depending on the snake species. Randomised clinical trials have used varied outcome measures that do not allow results to be compared or combined. In accordance with the Core Outcomes Measurements in Effectiveness Trials (COMET) initiative, this systematic review aims to support the development of a globally relevant core outcome set for snakebite.

METHODS

All randomised controlled trials, secondary analyses of randomised controlled trials and study protocols investigating the efficacy of therapeutics for human snakebite envenoming were eligible for inclusion. Study screening and data extraction were conducted in duplicate by two independent reviewers. All primary and secondary outcome measures were extracted and compiled, as were adverse event outcome measures. Similar outcome measures were grouped into domains. The study was prospectively registered with PROSPERO: CRD42020196160.

RESULTS

This systematic review included 43 randomised controlled trials, two secondary analyses and 13 study protocols. A total of 382 outcome measures were extracted and, after duplicates were merged, there were 153 unique outcomes. The most frequently used outcome domain ('venom antigenaemia') was included in less than one third of the studies. The unique outcomes were classified into 60 outcome domains. Patient-centred outcomes were used in only three of the studies.

DISCUSSION

Significant heterogeneity in outcome measures exists in snakebite clinical trials. Consensus is needed to select outcome measures that are valid, reliable, patient-centred and feasible. The results of this systematic review strongly support the development of a core outcome set for use in snakebite clinical trials.

Chronic health effects and cost of snakebite

The burden of disability among survivors and the socio-economic impact of snakebite have not been adequately researched. We reviewed original research articles, case reports and small case series relating to chronic physical, mental and psycho-social disability and economic burden of snakebite. Both physical and psychological health problems seem common in snakebite survivors and can lead to disability and loss of productivity. Chronic physical health effects, musculoskeletal disability being the commonest, can be largely attributed to limited and delayed access to optimal treatment of acute envenoming. The economic burden is considerable, and includes health system costs, out-of-pocket expenditure and opportunity costs, with regional variations. Health systems should be more responsive to needs and circumstances of bite victims, and a more holistic approach should be developed in the treatment of snakebite which incorporates the management of chronic health effects.

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Limited attention has been paid to chronic disability and the socio-economic impact of snakebite.

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Physical and psychological health problems occur in snakebite survivors leading to disability and loss of productivity.

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Chronic health effects can be largely attributed to limited and delayed access to optimal treatment of acute envenoming.

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Economic burden includes health system costs, out-of-pocket expenditure and opportunity costs.

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Health systems should be responsive to needs and circumstances of bite victims including care of chronic health effects.

Cross-cultural adaptation and validation of the Amharic version of Roland Morris Disability Questionnaire in people with low back pain in Ethiopia

PURPOSE

Cross-culturally translate, adapt, and validate Roland Morris Disability Questionnaire (RMDQ) in Amharic language in Ethiopia.

METHODS

The English version RMDQ was translated into Amharic and back-translated into English. An expert review committee reviewed the translations and created Amharic version of the RMDQ (RMDQ-Am). Pilot testing and cognitive debriefing of the RMDQ-Am were conducted with a sample of 20 individuals with LBP. The RMDQ-Am was administered to 240 individuals with LBP from three rehabilitation centers to determine its psychometric properties. Internal consistency of the tool was determined by Cronbach's alpha. Test-retest reliability was determined by the Intraclass correlation coefficient. The Standard Error of Measurement (SEM), Minimum Detectable Change (MDC), and the Bland Altman Limit of Agreement (LOA) was also determined. The Short-Form Health Survey (SF-36) Bodily Pain and Physical Functioning subscales were used to assess convergent validity. Exploratory Factor Analysis (EFA) was used to determine the dimensionality of the tool.

RESULTS

RMDQ-Am demonstrated good internal consistency (α = 0.88), excellent test-retest reliability (ICC = 0.91), SEM (1.64), MDC (3.55), and good LOA. There is a significant moderate correlation between RMDQ-Am and the Physical Functioning (Rho = -0.62, p < 0.01) and Bodily Pain (BP) (Rho = -0.41, p < 0.01) subscales of the SF-36. Exploratory Factor Analysis demonstrates that the Amharic version of RMDQ is a primary one and secondary four-factor model [The Kaiser Meyer Olkin = 0.877, X² (df) =1413.278/190, p < 0.001].

CONCLUSION

RMDQ-Am is a reliable and valid tool that can be used in both clinical practice and research with the Ethiopian LBP population.IMPLICATION FOR REHABILITATIONDespite LBP being a concern in Ethiopia, the magnitude of disability related to this phenomenon is not studied in the country, mainly due to the absence of validated LBP specific patient-reported outcome measures such as the Roland Morris Disability Questionnaire (RMDQ).The RMDQ was successfully translated, adapted, and validated into the Amharic language and the Ethiopian context (RMDQ-Am).The RMDQ-Am is a reliable outcome measure among the Ethiopian population with LBP, as demonstrated by the good internal consistency (α = 0.88) and excellent test-retest reliability (ICC = 0.91).There is a moderate negative correlation between the RMDQ-Am and the Physical Functioning (Rho = -0.62, p < 0.01) and Bodily Pain (Rho = -0.41, p < 0.01) subscales of the SF-36.The RMDQ-Am can be used in clinical and research settings to measure LBP-related disability and its impact among individuals living with LBP in Ethiopia.

Review of North American pit viper antivenoms

PURPOSE

For the first time in nearly 20 years, 2 antigen-binding fragment (Fab) antivenoms are available to treat patients who incur North American pit viper snakebites: Crotalidae polyvalent immune Fab (ovine), or simply FabAV; and Crotalidae immune F(ab')2 (equine), or simply F(ab')2. Pharmacists are in a key position for the selection, dosing, reconstitution, administration, and monitoring of antivenom therapy; however, they encounter inconsistent exposure and experience with these drugs. Thus, an updated review of the literature is necessary.

METHODS

The search strategy and selection incorporated both controlled vocabulary terms and keywords to describe concepts relevant to the search. Retrieval was limited to literature published from 1997 to the present in English, Portuguese, or Spanish.

RESULTS

Given the paucity of available prospective literature, the authors elected to include all prospective evidence to best describe the role of antivenom. For the primary literature review, manuscripts were excluded if they were observational studies, conference abstracts, narrative or opinion articles, letters to the editor, or in-progress studies.

CONCLUSION

While there is limited evidence-based guidance on the superiority of F(ab')2 to FabAV, or vice versa, individual and regional considerations should contribute to formulary decisions. Pharmacists must play a role in the development of clinical pathways to ensure appropriate evaluation, supportive care, and antivenom procurement, administration, and monitoring.

Recovery from Copperhead Snake Envenomation: Role of Age, Sex, Bite Location, Severity, and Treatment

INTRODUCTION

Few data exist to understand the recovery phase of pit viper envenomation. A recently published placebo-controlled clinical trial affords this opportunity. The purpose of this study is to examine the time course of recovery from copperhead snake (Agkistrodon contortrix) envenomation patients managed with and without the use of antivenom, stratified by age, sex, anatomic site of envenomation, initial severity of envenomation, and geographic region.

METHODS

This is a post-hoc subgroup analysis of data from a multi-center double-blinded clinical trial of Fab antivenom (FabAV) vs. placebo. Outcomes were the Patient-Specific Functional Scale (PSFS) score at 3, 7, 10, and 14 days after envenomation. Least-squares mean PSFS score curves were calculated for each subgroup, and repeated measures ANOVA was used to estimate between-group comparisons.

RESULTS

Seventy-two subjects were included, of whom 44 received FabAV. Males demonstrated better overall recovery than females (model predicted PSFS score 6.18 vs 4.99; difference 1.19; 95% CI 0.12 to 2.25; p = 0.029). No sex difference was found in response to FabAV. Overall recovery and effect of FabAV were similar in adult vs adolescent patients, patients with upper vs lower extremity envenomation, and patients with initially mild vs moderate envenomation signs. Analysis by geographic location was not successful due to ANOVA mode instability.

CONCLUSIONS

Male victims of copperhead snake envenomation demonstrate slightly better recovery than females, but response to Fab antivenom overall is similar across all subgroups studied.

Validity and reliability of telephone administration of the patient-specific functional scale for the assessment of recovery from snakebite envenomation

Objectives

Although more than 1.8 million people survive snakebite envenomation each year, their recovery is understudied. Obtaining long-term follow-up is challenging in both high- and low-resource settings. The Patient-Specific Functional Scale (PSFS) is an easily administered, well-accepted patient-reported outcome that is validated for assessing limb recovery from snakebite envenomation. We studied whether the PSFS is valid and reliable when administered by telephone.

Methods

This is a secondary analysis of data from a randomized clinical trial. We analyzed the results of PSFS collected in-person on days 3, 7, 14, 21, and 28 and by telephone on days 10, 17, and 24. We assessed the following scale psychometric properties: (a) content validity (ceiling and floor effects), (b) internal structure and consistency (Cronbach’s alpha), and (c) temporal and external validity using Intraclass Correlation Coefficient (ICC). Temporal stability was assessed using Spearman’s correlation coefficient and agreement between adjacent in-person and telephonic assessments with Cohen’s kappa. Bland Altman analysis was used to assess differential bias in low and high score results.

Results

Data from 74 patients were available for analysis. Floor effects were seen in the early post-injury time points (median: 3 (IQR: 0, 5) at 3 days post-enrollment) and ceiling effects in the late time points (median: 9 (IQR: 8, 10). Internal consistency was good to excellent with both in-person (Cronbach α: 0.91 (95%CI 0.88, 0.95)) and telephone administration (0.81 (0.73, 0.89). Temporal stability was also good (ICC: 0.83 (0.72, 0.89) in-person, 0.80 (0.68, 0.88) telephone). A strong linear correlation was found between in-person and telephone administration (Spearman’s ρ: 0.83 (CI: 0.78, 0.84), consistency was assessed as excellent (Cohen’s κ 0.81 (CI: 0.78, 0.84), and Bland Altman analysis showed no systematic bias.

Conclusions

Telephone administration of the PSFS provides valid, reliable, and consistent data for the assessment of recovery from snakebite envenomation.

Snakebite envenomation is an important but neglected tropical disease that impacts millions of people worldwide each year. These bites lead to both death and permanent disability. As they occur in tropical and subtropical regions, they primarily impact people from low-income areas of the world. As potential new treatments are being developed, we must understand their potential benefit in humans before they can be widely disseminated. Performing these human studies requires the ability to determine how patients recovered with these treatments. Having people return for evaluation during recovery is difficult in these low-income regions. We evaluated the ability to use a telephone version of an already accepted measurement of recovery in snakebite, the Patient-Specific Functional Scale. This study demonstrates that using this telephone-administered measure is feasible, valid, and reliable. With the results of this study, we now have an important tool to easily measure recovery in areas where snakebite predominates. This tool will help snakebite envenomation researchers evaluate the potential benefit of new treatments and accelerate the process of bringing new effective treatments to those snakebite patients in the most need.