Model-Based versus Clinical Prediction of the Spirometric Response to Lung Volume Reduction Surgery

Abstract

Background: Lung volume reduction surgery (LVRS) improves symptoms and lung function in selected patients with severe emphysema. Objectives: We investigated whether models based on physiologic and radiologic predictors discriminated patients with a favorable from those with a poor spirometric response to LVRS. Methods: Data of a derivation cohort of 70 patients who had previously undergone LVRS served to develop two types of prediction models, lookup functions and logistic regression equations. Presence or absence of improvement in forced expiratory volume in 1 s (FEV₁) ≧300 ml and forced vital capacity (FVC) ≧500 ml represented dichotomous outcomes. The residual volume/total lung capacity ratio, CT-radiological emphysema heterogeneity scores and diffusing capacity, a marker of emphysema severity, were the predictors. Models were used to predict spirometric outcomes for a validation cohort of 60 emphysema patients referred for LVRS. Furthermore, the surgeon preoperatively estimated outcomes based on all available clinical data but blinded to model predictions. Spirometric changes within 6 months following surgery were compared to predictions. Results: Median FEV₁ in the validation cohort increased from 0.69 to 1.00 liters (+41%), and FVC from 2.07 to 2.78 liters (+29%; p < 0.05 for changes). Lookup functions and logistic regression equations identified patients experiencing major increases in FEV₁ ≧300 ml and FVC ≧500 ml with an accuracy quantified by areas under the receiver-operating characteristic curves of 0.72 to 0.76 (all areas >0.5, p < 0.05). Predictions by the surgeon had an accuracy of 0.71 to 0.78 (p = NS vs. models). Conclusions: The accuracy of models based on three predictors was fair and similar to assessment by an experienced surgeon based on all available clinical information. Prediction models may contribute to the consistent assessment of LVRS candidates.

Prognostic models for outcome prediction in patients with chronic obstructive pulmonary disease: systematic review and critical appraisal

“…Supplementary table F shows all the external validation studies of the prognostic models for outcome prediction in COPD patients 2325 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81…”

A comprehensive review of predictive and prognostic composite factors implicated in the heterogeneity of treatment response and outcome across disease areas

“…The evidence review also identified several studies in disease states other than cancer, CVD, psychological disorders and disability. Other disease areas addressed by this review included respiratory disease (two studies) (35,36), diabetes (one study) (37), epilepsy (one study) (6), Gaucher disease (one study) (38) and muscle mass deficiency (one study) (39). Of these studies, one was a Level 1, two were Level 2, two were Level 3, and one was Level 4 according to the NICE quality ranking criteria.…”

A Patient with GOLD Stage 3 COPD « cured » by One-Way Endobronchial Valves

“…Although positive results have been reported after EBV treatment in homogeneous emphysema [10], better results are to be expected in very heterogeneous emphysema and particularly lobar emphysema as exemplified by the present case. In clinical studies, only the RV/TLC ratio that was proposed in the mathematical model by Fessler and Permutt [19] was consistently shown to predict a positive functional outcome after surgical lung volume reduction [26,27,28]. Moreover, for EBV treatment, it has been shown that fissure integrity [29] and absence of collateral ventilation [16] are important for achieving lobar atelectasis.…”