A randomized clinical trial of isolated ambulatory phlebectomy versus saphenous thermal ablation with concomitant phlebectomy (SAPTAP Trial).

BACKGROUND: Current treatment of patients with saphenous trunk and tributary incompetence consists of truncal ablation with concomitant, delayed or no treatment of the tributary. However, reflux of the saphenous trunk may be reversible after treatment of the incompetent tributary. The aim of this study was to determine whether single ambulatory phlebectomy with or without delayed endovenous truncal ablation (SAP) is non-inferior to thermal endovenous ablation with concomitant phlebectomy (TAP), and whether SAP is a cost-effective alternative to TAP. METHODS: A multicentre, non-inferiority RCT was conducted in patients with an incompetent great saphenous vein or anterior accessory saphenous vein with one or more incompetent tributaries. Participants were randomized to receive SAP or TAP. After 9 months, additional truncal treatment was considered for SAP patients with remaining symptoms. The primary outcome was VEnous INsufficiency Epidemiological and Economic Study Quality of Life/Symptoms (VEINES-QOL/Sym score) after 12 months. Secondary outcomes were, among others, cost-effectiveness, perceived improvement of symptoms, and anatomical success. RESULTS: Some 464 patients received the allocated treatment (SAP 227, TAP 237). VEINES-QOL scores were 52.7 (95 per cent c.i. 51.9 to 53.9) for SAP and 53.8 (53.3 to 55.1) for TAP; VEINES-Sym scores were 53.5 (52.6 to 54.4) and 54.2 (54.0 to 55.6) respectively. Fifty-eight patients (25.6 per cent) in the SAP group received additional truncal ablation. Treatment with SAP was less costly than treatment with TAP. CONCLUSION: One year after treatment, participants who underwent SAP had non-inferior health-related quality of life compared with those who had TAP. Treatment with SAP was a cost-effective alternative to TAP at 12 months. REGISTRATION NUMBER: NTR 4821 (www.trialregister.nl).

Stratification of COPD patients towards personalized medicine: reproduction and formation of clusters.

BACKGROUND: The global initiative for chronic obstructive lung disease (GOLD) 2020 emphasizes that there is only a weak correlation between FEV1, symptoms and impairment of the health status of patients with chronic obstructive pulmonary disease (COPD). Various studies aimed to identify COPD phenotypes by cluster analyses, but behavioral aspects besides smoking were rarely included. METHODS: The aims of the study were to investigate whether (i) clustering analyses are in line with the classification into GOLD ABCD groups; (ii) clustering according to Burgel et al. (Eur Respir J. 36(3):531-9, 2010) can be reproduced in a real-world COPD cohort; and (iii) addition of new behavioral variables alters the clustering outcome. Principal component and hierarchical cluster analyses were applied to real-world clinical data of COPD patients newly referred to secondary care (n = 155). We investigated if the obtained clusters paralleled GOLD ABCD subgroups and determined the impact of adding several variables, including quality of life (QOL), fatigue, satisfaction relationship, air trapping, steps per day and activities of daily living, on clustering. RESULTS: Using the appropriate corresponding variables, we identified clusters that largely reflected the GOLD ABCD groups, but we could not reproduce Burgel's clinical phenotypes. Adding six new variables resulted in the formation of four new clusters that mainly differed from each other in the following parameters: number of steps per day, activities of daily living and QOL. CONCLUSIONS: We could not reproduce previously identified clinical COPD phenotypes in an independent population of COPD patients. Our findings therefore indicate that COPD phenotypes based on cluster analysis may not be a suitable basis for treatment strategies for individual patients.

Does the 2013 GOLD classification improve the ability to predict lung function decline, exacerbations and mortality: a post-hoc analysis of the 4-year UPLIFT trial.

BACKGROUND: The 2013 GOLD classification system for COPD distinguishes four stages: A (low symptoms, low exacerbation risk), B (high symptoms, low risk), C (low symptoms, high risk) and D (high symptoms, high risk). Assessment of risk is based on exacerbation history and airflow obstruction, whatever results in a higher risk grouping. The previous system was solely based on airflow obstruction. Earlier studies compared the predictive performance of new and old classification systems with regards to mortality and exacerbations. The objective of this study was to compare the ability of both classifications to predict the number of future (total and severe) exacerbations and mortality in a different patient population, and to add an outcome measure to the comparison: lung function decline. METHODS: Patient-level data from the UPLIFT trial were used to analyze 4-year survival in a Weibull model, with GOLD stages at baseline as covariates. A generalized linear model was used to compare the numbers of exacerbations (total and severe) per stage. Analyses were repeated with stages C and D divided into substages depending on lung function and exacerbation history. Lung function decline was analysed in a repeated measures model. RESULTS: Mortality increased from A to D, but there was no difference between B and C. For the previous GOLD stages 2-4, survival curves were clearly separated. Yearly exacerbation rates were: 0.53, 0.72 and 0.80 for stages 2-4; and 0.35, 0.45, 0.58 and 0.74 for A-D. Annual rates of lung function decline were: 47, 38 and 26 ml for stages 2-4 and 44, 48, 38 and 39 for stages A-D. With regards to model fit, the new system performed worse at predicting mortality and lung function decline, and better at predicting exacerbations. Distinguishing between the sub-stages of high-risk led to substantial improvements. CONCLUSIONS: The new classification system is a modest step towards a phenotype approach. It is probably an improvement for the prediction of exacerbations, but a deterioration for predicting mortality and lung function decline. TRIAL REGISTRATION: ClinicalTrials.gov NCT00144339 (September 2, 2005).

Not simply more of the same: distinguishing between patient heterogeneity and parameter uncertainty.

In cost-effectiveness (CE) Markov models, heterogeneity in the patient population is not automatically taken into account. We aimed to compare methods of dealing with heterogeneity on estimates of CE, using a case study in chronic obstructive pulmonary disease (COPD). We first present a probabilistic sensitivity analysis (PSA) in which we sampled only from distributions representing parameter uncertainty. This ignores any heterogeneity. Next, we explored heterogeneity by presenting results for subgroups, using a method that samples parameter uncertainty simultaneously with heterogeneity in a single-loop PSA. Finally, we distinguished parameter uncertainty from heterogeneity in a double-loop PSA by performing a nested simulation within each PSA iteration. Point estimates and uncertainty differed substantially between methods. The incremental CE ratio (ICER) ranged from € 4900 to € 13,800. The single-loop PSA led to a substantially different shape of the CE plane and an overestimation of the uncertainty compared with the other 3 methods. The CE plane for the double-loop PSA showed substantially less uncertainty and a stronger negative correlation between the difference in costs and the difference in effects compared with the other methods. This came at the cost of higher calculation times. Not accounting for heterogeneity, subgroup analysis and the double-loop PSA can be viable options, depending on the decision makers' information needs. The single-loop PSA should not be used in CE research. It disregards the fundamental differences between heterogeneity and sampling uncertainty and overestimates uncertainty as a result.

Adjusting for COPD severity in database research: developing and validating an algorithm.

PURPOSE: When comparing chronic obstructive lung disease (COPD) interventions in database research, it is important to adjust for severity. Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines grade severity according to lung function. Most databases lack data on lung function. Previous database research has approximated COPD severity using demographics and healthcare utilization. This study aims to derive an algorithm for COPD severity using baseline data from a large respiratory trial (UPLIFT). METHODS: Partial proportional odds logit models were developed for probabilities of being in GOLD stages II, III and IV. Concordance between predicted and observed stage was assessed using kappa-statistics. Models were estimated in a random selection of 2/3 of patients and validated in the remainder. The analysis was repeated in a subsample with a balanced distribution across severity stages. Univariate associations of COPD severity with the covariates were tested as well. RESULTS: More severe COPD was associated with being male and younger, having quit smoking, lower BMI, osteoporosis, hospitalizations, using certain medications, and oxygen. After adjusting for these variables, co-morbidities, previous healthcare resource use (eg, emergency room, hospitalizations) and inhaled corticosteroids, xanthines, or mucolytics were no longer independently associated with COPD severity, although they were in univariate tests. The concordance was poor (kappa = 0.151) and only slightly better in the balanced sample (kappa = 0.215). CONCLUSION: COPD severity cannot be reliably predicted from demographics and healthcare use. This limitation should be considered when interpreting findings from database studies, and additional research should explore other methods to account for COPD severity.