Comparison of health-related quality of life measures in chronic obstructive pulmonary disease

<p>Abstract</p> <p>Background</p> <p>The aims of this study were: (1) to compare the discriminative ability of a disease-specific instrument, the St. George's Respiratory Questionnaire (SGRQ) to generic instruments (i.e., EQ-5D and SF-36); and (2), to evaluate the strength of associations among clinical and health-related quality of life (HRQL) measures in chronic obstructive pulmonary disease (COPD).</p> <p>Methods</p> <p>We analyzed data collected from 120 COPD patients in a Veterans Affairs hospital. Patients self-completed two generic HRQL measures (EQ-5D and SF-36) and the disease-specific SGRQ. The ability of the summary scores of these HRQL measures to discriminate COPD disease severity based on Global Obstructive Lung Disease (GOLD) stage was assessed using relative efficiency ratios (REs). Strength of correlation was used to further evaluate associations between clinical and HRQL measures.</p> <p>Results</p> <p>Mean total scores for PCS-36, EQ-VAS and SGRQ were significantly lower for the more severe stages of COPD (<it>p </it>< 0.05). Using SGRQ total score as reference, the summary scores of the generic measures (PCS-36, MCS-36, EQ index, and EQ-VAS) all had REs of <1. SGRQ exhibited a stronger correlation with clinical measures than the generic summary scores. For instance, SGRQ was moderately correlated with FEV₁(<it>r </it>= 0.43), while generic summary scores had trivial levels of correlation with FEV₁(<it>r </it>< 0.2).</p> <p>Conclusions</p> <p>The SGRQ demonstrated greater ability to discriminate among different levels of severity stages of COPD than generic measures of health, suggestive that SGRQ may provide COPD studies with greater statistical power than EQ-5D and SF-36 summary scores to capture meaningful differences in clinical severity.</p

Estimation of minimally important differences in EQ-5D utility and VAS scores in cancer

We wish to correct a mistake in the abstract and conclusion of our published paper [1]. In the abstract and conclusion, the MID for EQ-VAS score should be reported as 7 rather than 0.07. EQ-VAS scores range from 0 to 100, while EQ-5D index-based scores are anchored by 0 (dead) and 1 (perfect health). The specific wording in the conclusion of the abstract should read “Important differences in EQ-5D utility and VAS scores were similar for all cancers and lung cancer, with the lower end of the range of estimates closer to the MID, i. e. 0.08 for UK-index scores, 0.06 for US-index scores, and 7 for VAS scores. Author details

Are decisions using cost-utility analyses robust to choice of SF-36/SF-12 preference-based algorithm?

BACKGROUND: Cost utility analysis (CUA) using SF-36/SF-12 data has been facilitated by the development of several preference-based algorithms. The purpose of this study was to illustrate how decision-making could be affected by the choice of preference-based algorithms for the SF-36 and SF-12, and provide some guidance on selecting an appropriate algorithm. METHODS: Two sets of data were used: (1) a clinical trial of adult asthma patients; and (2) a longitudinal study of post-stroke patients. Incremental costs were assumed to be $2000 per year over standard treatment, and QALY gains realized over a 1-year period. Ten published algorithms were identified, denoted by first author: Brazier (SF-36), Brazier (SF-12), Shmueli, Fryback, Lundberg, Nichol, Franks (3 algorithms), and Lawrence. Incremental cost-utility ratios (ICURs) for each algorithm, stated in dollars per quality-adjusted life year ($/QALY), were ranked and compared between datasets. RESULTS: In the asthma patients, estimated ICURs ranged from Lawrence's SF-12 algorithm at $30,769/QALY (95$63,492/QALY (95% CI: 48,780 to 83,333). ICURs for the stroke cohort varied slightly more dramatically. The MEPS-based algorithm by Franks et al. provided the lowest ICUR at $27,972/QALY (95$50,000/QALY and did not have confidence intervals that overlapped with most of the other algorithms. The ICUR-based ranking of algorithms was strongly correlated between the asthma and stroke datasets (r = 0.60). CONCLUSION: SF-36/SF-12 preference-based algorithms produced a wide range of ICURs that could potentially lead to different reimbursement decisions. Brazier's SF-36 and SF-12 algorithms have a strong methodological and theoretical basis and tended to generate relatively higher ICUR estimates, considerations that support a preference for these algorithms over the alternatives. The "second-generation" algorithms developed from scores mapped from other indirect preference-based measures tended to generate lower ICURs that would promote greater adoption of new technology. There remains a need for an SF-36/SF-12 preference-based algorithm based on the US general population that has strong theoretical and methodological foundations

Nine years of comparative effectiveness research education and training: initiative supported by the PhRMA Foundation

The term comparative effectiveness research (CER) took center stage with passage of the American Recovery and Reinvestment Act (2009). The companion US$1.1 billion in funding prompted the launch of initiatives to train the scientific workforce capable of conducting and using CER. Passage of the Patient Protection and Affordable Care Act (2010) focused these initiatives on patients, coining the term ‘patient-centered outcomes research’ (PCOR). Educational and training initiatives were soon launched. This report describes the initiative of the Pharmaceutical Research and Manufacturers Association of America (PhRMA) Foundation. Through provision of grant funding to six academic Centers of Excellence, to spearheading and sponsoring three national conferences, the PhRMA Foundation has made significant contributions to creation of the scientific workforce that conducts and uses CER/PCOR

Carbon network evolution from dimers to sheets in superconducting ytrrium dicarbide under pressure

Carbon-bearing compounds display intriguing structural diversity, due to variations in hybrid bonding of carbon. Here, first-principles calculations and unbiased structure searches on yttrium dicarbide at pressure reveal four new structures with varying carbon polymerisation, in addition to the experimentally observed high-temperature low-pressure I4/mmm dimer phase. At low pressures, a metallic C2/m phase (four-member single-chain carbide) is stable, which transforms into a Pnma phase (single-chain carbide) upon increasing pressure, with further transformation to an Immm structure (double-chain carbide) at 54 GPa and then to a P6/mmm phase (sheet carbide) at 267 GPa. Yttrium dicarbide is structurally diverse, with carbon bonded as dimers (at lowest pressure), four-member single chains, infinite single chains, double chains and eventually sheet structures on compression. Electron–phonon coupling calculations indicate that the high-pressure phases are superconducting. Our results aid the understanding and design of new superconductors and illuminate pressure-induced carbon polymerisation in carbides

Comparing responsiveness of the EQ-5D-5L, EQ-5D-3L and EQ VAS in stroke patients

Aims: To date, evidence to support the construct validity of the EQ-5D-5L has primarily focused on cross-sectional data. The aims of this study were to examine the responsiveness of EQ-5D-5L in patients with stroke and to compare it with responsiveness of EQ-5D-3L and visual analogue scale (EQ VAS). Methods: We performed an observational longitudinal cohort study of patients with stroke. At 1 week and 4 months post-stroke, patients were assessed with modified Rankin Scale (mRS) and Barthel Index (BI) and were administered the EQ-5D-5L and EQ-5D-3L, including the EQ VAS. The EQ-5D-5L index scores were derived using the crosswalk methodology developed by the EuroQol Group. We classified patients according to two external criteria, based on mRS or BI, into 3 categories: ‘improvement,’ ‘stable’ or ‘deterioration’. We assessed the responsiveness of each measure in each patient subgroup using: effect size (ES), standardized response mean (SRM), F-statistic, relative efficiency and area under the receiver operating characteristic curve. Results: A total of 112 patients (52 % females; mean age 70.6 years; 93 % ischemic stroke) completed all the instruments at both occasions. In subjects with clinical improvement, EQ-5D-5L was consistently responsive, showing moderate ES (0.51–0.71) and moderate to large SRM (0.69–0.86). In general, EQ-5D-3L index appeared to be more responsive (ES 0.63–0.82; SRM 0.77–1.06) and EQ VAS less responsive (ES 0.51–0.65; SRM 0.59–0.69) than EQ-5D-5L index. Conclusions: The EQ-5D-5L index, based on the crosswalk value set, seems to be appropriately responsive in patients with stroke, 4 months after disease onset. As far as EQ-5D-5L index is scored according to crosswalk approach, the EQ-5D-3L index appears to be more responsive in stroke population

Estimation of minimally important differences in EQ-5D utility and VAS scores in cancer

<p>Abstract</p> <p>Background</p> <p>Understanding what constitutes an important difference on a HRQL measure is critical to its interpretation. The aim of this study was to provide a range of estimates of minimally important differences (MIDs) in EQ-5D scores in cancer and to determine if estimates are comparable in lung cancer.</p> <p>Methods</p> <p>A retrospective analysis was conducted on cross-sectional data collected from 534 cancer patients, 50 of whom were lung cancer patients. A range of minimally important differences (MIDs) in EQ-5D index-based utility (UK and US) scores and VAS scores were estimated using both anchor-based and distribution-based (1/2 standard deviation and standard error of the measure) approaches. Groups were anchored using Eastern Cooperative Oncology Group performance status (PS) ratings and FACT-G total score-based quintiles.</p> <p>Results</p> <p>For UK-utility scores, MID estimates based on PS ranged from 0.10 to 0.12 both for all cancers and for lung cancer subgroup. Using FACT-G quintiles, MIDs were 0.09 to 0.10 for all cancers, and 0.07 to 0.08 for lung cancer. For US-utility scores, MIDs ranged from 0.07 to 0.09 grouped by PS for all cancers and for lung cancer; when based on FACT-G quintiles, MIDs were 0.06 to 0.07 in all cancers and 0.05 to 0.06 in lung cancer. MIDs for VAS scores were similar for lung and all cancers, ranging from 8 to 12 (PS) and 7 to 10 (FACT-G quintiles).</p> <p>Discussion</p> <p>Important differences in EQ-5D utility and VAS scores were similar for all cancers and lung cancer, with the lower end of the range of estimates closer to the MID, i.e. 0.08 for UK-index scores, 0.06 for US-index scores, and 0.07 for VAS scores.</p

Correction: Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa.

Correction to: 7 Aug 2015: The PLOS Neglected Tropical Diseases Staff (2015) Correction: Correction: Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa. PLoS Negl Trop Dis 9(8): e0003970. doi: 10.1371/journal.pntd.0003970

Respiratory and Bronchitic Symptoms Predict Intention to Quit Smoking among Current Smokers with, and at Risk for, Chronic Obstructive Pulmonary Disease

Rationale: Smoking cessation is the most important intervention for patients with chronic obstructive pulmonary disease (COPD). What leads smokers with COPD to quit smoking remains unknown