A technique for approximating transition rates from published survival analyses

© 2019 The Author(s). Background: Quality-adjusted-life-years (QALYs) are used to concurrently quantify morbidity and mortality within a single parameter. For this reason, QALYs can facilitate the discussion of risks and benefits during patient counseling regarding treatment options. QALYs are often calculated using partitioned-survival modelling. Alternatively, QALYs can be calculated using more flexible and informative state-transition models populated with transition rates estimated using multistate modelling (MSM) techniques. Unfortunately the latter approach is considered not possible when only progression-free survival (PFS) and overall survival (OS) analyses are reported. Methods: We have developed a method that can be used to estimate approximate transition rates from published PFS and OS analyses (we will refer to transition rates estimated using full multistate methods as true transition rates). Results: The approximation method is more accurate for estimating the transition rates out of health than the transition rate out of illness. The method tends to under-estimate true transition rates as censoring increases. Conclusions: In this article we present the basis for and use of the transition rate approximation method. We then apply the method to a case study and evaluate the method in a simulation study

A General Population Utility Valuation Study For Metastatic Epidural Spinal Cord Compression Health States.

STUDY DESIGN: General population utility valuation study OBJECTIVES.: This study obtained utility valuations from a Canadian general population perspective for 31 unique Metastatic Epidural Spinal Cord Compression (MESCC) health states and determined the relative importance of MESCC-related consequences on quality-of-life. SUMMARY OF BACKGROUND DATA: Few prospective studies on the treatment of MESCC have collected quality-adjusted-life-year weights (termed utilities ). Utilities are an important summative measure which distills health outcomes to a single number that can assist healthcare providers, patients, and policy makers in decision making. METHODS: We recruited a sample of 1138 adult Canadians using a market research company. Quota sampling was used to ensure that the participants were representative of the Canadian population in terms of age, gender, and province of residence. Using the validated MESCC module for the Self-administered Online Assessment of Preferences (SOAP) tool, participants were asked to rate 6 of the 31 MESCC health states, each of which presented varying severities of 5 MESCC-related dysfunctions (dependent; non-ambulatory; incontinent; pain; other symptoms). RESULTS: Participants equally valued all MESCC-related dysfunctions which followed a pattern of diminishing marginal disutility (each additional consequence resulted in a smaller incremental decrease in utility than the previous). These results demonstrate that the general population values physical function equal to other facets of quality-of-life. CONCLUSIONS: We provide a comprehensive set of ex ante utility estimates for MESCC health states that can be used to help inform decision making. This is the first study reporting direct utility valuation for a spinal disorder. Our methodology offers a feasible solution for obtaining quality-of-life data without collecting generic health status questionnaire responses from patients. LEVEL OF EVIDENCE: 4

Macular hole formation, progression, and surgical repair: case series of serial optical coherence tomography and time lapse morphing video study

<p>Abstract</p> <p>Background</p> <p>To use a new medium to dynamically visualize serial optical coherence tomography (OCT) scans in order to illustrate and elucidate the pathogenesis of idiopathic macular hole formation, progression, and surgical closure.</p> <p>Case Presentations</p> <p>Two patients at the onset of symptoms with early stage macular holes and one patient following repair were followed with serial OCTs. Images centered at the fovea and at the same orientation were digitally exported and morphed into an Audiovisual Interleaving (avi) movie format. Morphing videos from serial OCTs allowed the OCTs to be viewed dynamically. The videos supported anterior-posterior vitreofoveal traction as the initial event in macular hole formation. Progression of the macular hole occurred with increased cystic thickening of the fovea without evidence of further vitreofoveal traction. During cyst formation, the macular hole enlarged as the edges of the hole became elevated from the retinal pigment epithelium (RPE) with an increase in subretinal fluid. Surgical repair of a macular hole revealed initial closure of the macular hole with subsequent reabsorption of the sub-retinal fluid and restoration of the foveal contour.</p> <p>Conclusions</p> <p>Morphing videos from serial OCTs are a useful tool and helped illustrate and support anterior-posterior vitreofoveal traction with subsequent retinal hydration as the pathogenesis of idiopathic macular holes.</p