Dataset Information

Predicting Lung Function Following Lobectomy: A New Method to Adjust for Inherent Selection Bias.

ABSTRACT: BACKGROUND:Predictions that overestimate post-lobectomy lung function are more likely than underestimates to lead to lobectomy. Studies of post-lobectomy lung function have included only surgical patients, so overestimates are overrepresented. This selection bias has led to incorrect estimates of prediction bias, which has led to inaccurate threshold values for determining lobectomy eligibility. OBJECTIVE:The objective of this study was to demonstrate and adjust for this selection bias in order to arrive at correct estimates of prediction bias, the 95% limits of agreement, and adjusted threshold values for determining when exercise testing is warranted. METHODS:We conducted a retrospective study of patients evaluated for lobectomy. We used multiple imputations to determine postoperative results for patients who did not have surgery because their predicted postoperative values were low. We combined these results with surgical patients to adjust for selection bias. We used the Bland-Altman method and the bivariate normal distribution to determine threshold values for surgical eligibility. RESULTS:Lobectomy evaluation was performed in 114 patients; 79 had lobectomy while 35 were ineligible based on predicted values. Prediction bias using the Bland-Altman method changed significantly after controlling for selection bias. To achieve a postoperative FEV1 > 30% and DLCO ?30%, a predicted FEV1 > 46% and DLCO ?53% were required. Compared to current guidelines, using these thresholds would change management in 17% of cases. CONCLUSION:The impact of selection bias on estimates of prediction accuracy was significant but can be corrected. Threshold values for determining surgical eligibility should be reassessed.

SUBMITTER: Ontiveros N

PROVIDER: S-EPMC6538262 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Predicting Lung Function Following Lobectomy: A New Method to Adjust for Inherent Selection Bias.

Ontiveros Narda N Eapen-John David D Osorio Natasha N Song Juhee J Li Liang L Sheshadri Ajay A Tiang Xin X Ghosh Natasha N Vaporciyan Ara A Correa Arlene A Walsh Garrett G Grosu Horiana B HB Ost David E DE

Respiration; international review of thoracic diseases 20180926 5

<h4>Background</h4>Predictions that overestimate post-lobectomy lung function are more likely than underestimates to lead to lobectomy. Studies of post-lobectomy lung function have included only surgical patients, so overestimates are overrepresented. This selection bias has led to incorrect estimates of prediction bias, which has led to inaccurate threshold values for determining lobectomy eligibility.<h4>Objective</h4>The objective of this study was to demonstrate and adjust for this selection ...[more]

PMID: 30257257

Similar Datasets

Project description:Lone atrial fibrillation (AF) is associated with various ion channel gene sequence variants, notably the common S38G loss-of-function polymorphism in the KCNE1 K(+) channel ancillary subunit gene. New-onset postoperative AF (POAF) generally occurs 48-72 h after major surgery, particularly following procedures within the chest, but its molecular bases remain poorly understood. To begin to address this gap in knowledge, we analyzed molecular changes in the left atrium (LA) in relation to simultaneous changes in hemodynamics, LA effective refractory period (ERP), and the capacity to sustain electrically-induced AF following left upper lung lobectomy in swine. Relative to control pigs (no previous surgery), 3 days after lobectomy higher values for mean pulmonary artery pressure (16 ± 1 vs 22 ± 2 mmHg; P=0.045) and pulmonary vascular resistance (273 ± 47 vs 481 ± 63 dyns/cm(5); P=0.025) were evident, whereas other hemodynamic variables were unchanged. LA ERP trended toward reduction in lobectomy animals (187 ± 16 vs 170 ± 20 ms, P>0.05). None of the lobectomy pigs developed spontaneous POAF as assessed by telemetric ECG. However, all lobectomy pigs, but none of the controls, were able to sustain AF induced by a 10s burst of rapid pacing for ≥ 30 s (P=0.0079), independent of LA ERP; AF was sustained ≥ 60s in 3/5 postoperative pigs versus 0/5 controls and correlated with a shorter ERP overall (P=0.023). Transcriptomic analysis of LA tissue revealed 23 up-regulated and 10 down-regulated transcripts (≥ 1.5-fold, P<0.05) in lobectomy pigs. Strikingly, of the latter, KCNE1 down-regulation showed the statistically strongest link to surgery (2.0-fold, P=0.009), recapitulated at the protein level with Western blotting (P=0.039), suggesting KCNE1 down-regulation as a possible common mechanistic factor in POAF and lone AF. Of the up-regulated transcripts, while Teneurin-2 was the strongest linked (1.5-fold change, P=0.001), DSCR5 showed the highest induction (2.7-fold, P=0.02); this and other hits will be targeted in future functional studies.

Project description:Acute lung injury following lung resection surgery is not rare and often related to mortality. Although it has been a significant clinical and economic impact associated with increased intensive care unit (ICU) utilization, length of hospital stay, and associated cost, it is unpredictable. Aims of this study were to identify the modifiable risk factors of postoperative acute lung injury (PALI) following lung cancer surgery.We retrospectively analyzed medical records of 354 cases of lung cancer surgery in the tertiary university hospital from January 2012 to December 2015. PALI was defined as bilateral diffuse pulmonary infiltration on chest radiography, oxygenation failure (PaO2/FiO2 < 300), and absence of sign of left ventricular failure within a week from operation. We classified patients into either PALI group or non-PALI group and compared clinical characteristics of two groups. Logistic regression model was fitted to evaluate the risk factor of PALI.Among 354 cases of lung cancer surgeries, 287 lobectomies were analyzed. The overall incidence of PALI was 2.79% (8/287); four patients developed pneumonia with acute respiratory distress syndrome, and four patients developed ALI without clinical infection sign. There was no difference in baseline characteristics between PALI group and non-PALI group, but in operative parameters, a larger amount of fluid infusion was observed in PALI group. Logistic regression model showed underlying ischemic heart disease (OR 7.67, 95% CI 1.21-47.44, P = .03), interstitial lung disease (OR 30.36, 95% CI 2.30-401.52, P = .01), intravascular crystalloid fluid during surgery (OR 1.10, 95% CI 1.00-1.20, P = .04), and intraoperative transfusion (OR 56.4, 95% CI 3.53-901.39, P < .01) were risk factors of PALI. PALI increases ICU admission, use of mechanical ventilator, duration of hospital stay, and mortality.The clinical impact of PALI is marked. Significant independent risk factors have been identified in underlying ischemic heart disease, interstitial lung disease, intravascular crystalloid fluid, and transfusion during surgery.

Project description:An important assumption in observational studies is that sampled individuals are representative of some larger study population. Yet, this assumption is often unrealistic. Notable examples include online public-opinion polls, publication biases associated with statistically significant results, and in ecology, telemetry studies with significant habitat-induced probabilities of missed locations. This problem can be overcome by modeling selection probabilities simultaneously with other predictor-response relationships or by weighting observations by inverse selection probabilities. We illustrate the problem and a solution when modeling mixed migration strategies of northern white-tailed deer (Odocoileus virginianus). Captures occur on winter yards where deer migrate in response to changing environmental conditions. Yet, not all deer migrate in all years, and captures during mild years are more likely to target deer that migrate every year (i.e., obligate migrators). Characterizing deer as conditional or obligate migrators is also challenging unless deer are observed for many years and under a variety of winter conditions. We developed a hidden Markov model where the probability of capture depends on each individual's migration strategy (conditional versus obligate migrator), a partially latent variable that depends on winter severity in the year of capture. In a 15-year study, involving 168 white-tailed deer, the estimated probability of migrating for conditional migrators increased nonlinearly with an index of winter severity. We estimated a higher proportion of obligates in the study cohort than in the population, except during a span of 3 years surrounding back-to-back severe winters. These results support the hypothesis that selection biases occur as a result of capturing deer on winter yards, with the magnitude of bias depending on the severity of winter weather. Hidden Markov models offer an attractive framework for addressing selection biases due to their ability to incorporate latent variables and model direct and indirect links between state variables and capture probabilities.

Dataset Information

Predicting Lung Function Following Lobectomy: A New Method to Adjust for Inherent Selection Bias.

Publications

Predicting Lung Function Following Lobectomy: A New Method to Adjust for Inherent Selection Bias.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets