Survival of patients with chronic respiratory failure on long-term oxygen therapy and or non-invasive ventilation at home.

BACKGROUND & AIMS: Chronic respiratory failure (CRF) is the common fate of respiratory diseases where systemic effects contribute to outcomes. In a prospective cohort of home-treated patients with CRF, we looked for predictors of long-term survival including respiratory, nutritional and inflammatory dimensions. METHODS: 637 stable outpatients with CRF, 397 men, 68 ± 11 years, on long-term oxygen therapy and/or non-invasive ventilation from 21 chest clinics were enrolled and followed over 53 ± 31 months. CRF resulted from Chronic Obstructive Pulmonary Disease (COPD) in 48.5%, restrictive disorders 32%, mixed (obstructive and restrictive patterns) respiratory failure 13.5%, bronchiectasis 6%. Demographic characteristics, smoking habits, underlying respiratory diseases, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), arterial blood gases, 6-min walking distance (6MWD), hemoglobin, body mass index (BMI), serum albumin, transthyretin, C-reactive protein (CRP), history of respiratory assistance, antibiotic and oral corticosteroid use during the previous year were recorded. RESULTS: 322 deaths occurred during the follow-up. One-, five- and 8-year actuarial survival was 89%, 56% and 47%. By Cox univariate analysis, age, respiratory disease, PaO2, PaCO2, FEV1/FVC, BMI, 6MWD, activity score, type and length of home respiratory assistance, smoking habits, oral corticosteroid and antibiotic uses, albumin, transthyretin, hemoglobin and CRP levels were associated with survival. Multivariate analysis identified eight independent markers of survival: age, FEV1/FVC, PaO2, PaCO2, 6MWD, BMI, serum transthyretin, CRP ≥ 5 mg/l. CONCLUSIONS: In CRF, whatever the underlying diseases, besides the levels of obstructive ventilatory defect and gas exchange failure, 6MWD, BMI, serum transthyretin and CRP ≥ 5 mg/l predicted long-term survival identifying potential targets for nutritional rehabilitation.

Do public reports of provider performance make their data and methods available and accessible?

Public reports of provider performance are widespread and the methods used to generate the provider ratings differ across the sponsoring entities. We examined 115 hospital and 27 physician public reports to determine whether report sponsors made the methods used to score providers available and accessible. While nearly all websites made transparent some of the methods used to assess provider performance, we found substantial variation in the extent to which they fully adhered to recommended methods elements identified in the Consumer-Purchaser Disclosure Project's Patient Charter for performance reporting. Most public reports provided descriptions of the data sources, whether measures were endorsed, and the attribution approach. Least often made transparent were methods descriptions related to advanced provider review and reconsideration of results, reliability assessment, and case-mix adjustment. Future research should do more to identify the core elements that would lead consumer end users to have confidence in public reports.

Performances of Elasto-FibroTest(®), a combination between FibroTest(®) and liver stiffness measurements for assessing the stage of liver fibrosis in patients with chronic hepatitis C.

BACKGROUND: FibroTest(®) (FT), and liver stiffness measurement (LSM) are the most validated techniques for the non-invasive assessment of fibrosis in patients with chronic hepatitis C (CHC). The combination between FibroTest(®) and LSM has never been assessed using methods assuming that biopsy is not a perfect gold standard. AIM: The aim was to assess the performance of a new test the Elasto-FibroTest(®) (EFT) combining FibroTest(®) and LSM. METHODS: An integrated data base of 1289 patients with biopsy and 604 healthy volunteers was analyzed. EFT took into account the applicability of both tests, included two algorithms taking one for the diagnosis of advanced fibrosis (EFT-F2) and one for the diagnosis of cirrhosis (EFT-F4). Performances of EFTs were assessed by three methods: area under the ROC curve (AUROC), "Obuchowski method" (OBU) and 1 TAGS the "Latent class with random factor". RESULTS: For the diagnosis of advanced fibrosis EFT-F2 performances (specificity=0.99 and sensitivity=0.83) were not greater than the performances of FibroTest(®) alone (specificity=0.93 and sensitivity=0.99). For the diagnosis of cirrhosis, EFT-F4 performances were greater than those of FibroTest(®) alone, particularly for the sensitivity (0.88 vs. 0.74); when compared with LSM, EFT-F4 performances (specificity=0.99 and sensitivity=0.99) were also greater than those of LSM alone particularly because of its lower specificity (0.92). CONCLUSION: For the diagnosis of cirrhosis the Elasto-FibroTest(®) has higher performances than FibroTest(®) or FibroScan(®) alone. No improvement in performance has been observed for the diagnosis of advanced fibrosis vs. FibroTest(®) alone.

Relative performances of FibroTest, Fibroscan, and biopsy for the assessment of the stage of liver fibrosis in patients with chronic hepatitis C: a step toward the truth in the absence of a gold standard.

BACKGROUND & AIMS: Liver fibrosis stage is traditionally assessed with biopsy, an imperfect gold standard. Two widely used techniques, FibroTest®, and liver stiffness measurement (LSM) using Fibroscan® have been validated using biopsy, and therefore the true performances of these estimates are still unknown in the absence of a perfect reference. The aim was to assess the relative accuracy of FibroTest, LSM, and biopsy using methods without gold standard in patients with chronic hepatitis C (CHC) and controls. METHODS: A total of 1289 patients with CHC and 604 healthy volunteers, with assessment of fibrosis stage by the three techniques, and alanine aminotransferase (ALT) taken as a control test, were analyzed by latent class method with random effects. In the volunteers, the false positive risk of biopsy was obtained from a large surgical sample of four normal livers. RESULTS: The latent class model with random effects permitted to conciliate the observed data and estimates of test performances. For advanced fibrosis, the specificity/sensitivity was for FibroTest 0.93/0.70, LSM 0.96/0.45, ALT 0.79/0.78 and biopsy 0.67/0.63, and for cirrhosis FibroTest 0.87/0.41, LSM 0.93/0.39, ALT 0.78/0.08 and biopsy 0.95/0.51. The analysis of the discordances between pairs suggested that the variability of the model was mainly related to the discordances between biopsy and LSM (residuals>10; p<0.0001). CONCLUSIONS: A method without the use of a gold standard confirmed the accuracy of FibroTest and Fibroscan for the diagnosis of advanced fibrosis and cirrhosis in patients with chronic hepatitis C. The variability of the model was mostly due to the discordances between Fibroscan and biopsy.

FibroTest and Fibroscan performances revisited in patients with chronic hepatitis C. Impact of the spectrum effect and the applicability rate.

BACKGROUND: Two widely used biomarkers of fibrosis, FibroTest and liver stiffness measurement (LSM), have been mostly validated in patients with chronic hepatitis C (CHC) using the standard area under the ROC curve (sAUROC) which is not the most appropriate method due to the risk of fibrosis spectrum effect. Furthermore the performance of these biomarkers have not been assessed in "intention to diagnose" which takes into account the failures and non-reliable results. AIM: The aim was to compare the accuracy of FibroTest and LSM for the diagnosis of fibrosis using sAUROC, the pairwise comparison of fibrosis stages by Obuchowski measure (wAUROC), and these AUROCs reassessed after taking into account the applicability rates. METHODS: One thousand two hundred and eighty-nine patients with CHC and 604 healthy volunteers were analyzed. The performances of biomarkers assessed were compared in a patients-only group (P1: n=1289), in a population combining both patients and healthy volunteers (P2: n=1893) and in a simulated population (P3: n=1893) with the prevalence of stages observed in a reference population, to demonstrate the impact of spectrum effect. Applicability rates were estimated prospectively in 24,872 consecutive FibroTest and in 13,669 consecutive LSM examinations. RESULTS: Using wAUROC, the conclusions of studies with reliable results in P1 were different than in those of P2 and in P3. There was a lower performance of FibroTest versus LSM in P1 (0.864 [0.855-0.873] vs. 0.883 [0.874-0.892]; P=0.002) which was not found in P2 (0.893 [0.887-0.900] vs. 0.894 [0.887-0.901]; P=0.86) and in P3 (0.899 [0.893-0.905] vs 0.902 [0.895-0.909]; P=0.60). Using the sAUROC, in P1, P2 and P3, there was no significant difference between FibroTest and LSM performance for advanced fibrosis and a lower performance of FibroTest versus LSM for cirrhosis. In intention to diagnose, using wAUROCs performances were higher for FibroTest vs. LSM in P1 (0.857 [0.848-0.866] vs. 0.814 [0.807-0.821]; P<0.0001) and P2 (0.885 [0.879-0.892] vs. 0.743 [0.737-0.749]; P<0.0001), without difference in P3 (0.891 [0.885-0.897] vs. 0.894 [0.887-0.901]; P=0.90). Using sAUROC, the significant differences in favor of FibroTest vs LSM persisted also for the diagnosis of advanced fibrosis, both in P1 and P2 (P<0.0001) and for the diagnosis of cirrhosis in P1 (P<0.001). CONCLUSION: When the spectrum effects and applicability rates were taken into account, LSM had lower performance results than FibroTest for the diagnosis of fibrosis stages.