Quality of life after cardiac surgery the QUACS Study and benefit prediction model

Figures

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  Figure 1.. CONSORT Diagram of the QUACS Study. Levels of completeness of QoL data at each time point during the first and second years of post-surgery follow-up. Reasons for missingness include death, withdrawal of consent (abbreviated “WoC”), loss to follow-up (abbreviated “LFu”), and noncompletion of a questionnaire at a given time point while still alive and contributing to the study (column “Missing”). (*) For death, withdrawal of consent and loss to follow-up, cumulative numbers over the period of interest are provided. Abbreviations: LFu, loss to follow-up; QoL, quality of life; WoC, withdrawal of consent.

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  Figure 2.. Typical Patient’s QoL Trajectory After Cardiac Surgery. The solid grey line shows EQ5-T QoL status over time assuming 3 different reductions in QoL immediately after surgery (coloured dashed lines). The red shaded area represents surgery-related QoL loss or the “cost” of surgery in terms of QoL. T1 is the time at which the patient returns to baseline QoL. The green shaded area represents improvement over baseline QoL. T2 is the time at which the green shaded area equals the red shaded area and corresponds to the moment the surgery-related QoL loss has been compensated for by QoL improvement. Abbreviations: EQ5-T, EQ5 health thermometer; QoL, quality of life.

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  Figure 3.. Mean Change in QoL from the First Postoperative Measure for All Patients. Quality of life (y-axis) as a function of time (x-axis) after surgery (time 0) for all patients (individual grey lines) according to 2 QoL types: EQ-5D health thermometer (EQ5-T, upper plot) and utility (EQ5-U, lower plot). The brown line shows the average trend over all patients. On average for our cohort, QoL increases sharply from the first post-operative measurement during the first quarter, then improvement slows and a plateau is reached. As a composite end-point defined on 5 questions, EQ5-U shows less variability than EQ5-T, which is defined by a single patient input. Abbreviations: EQ5-T, EQ5 health thermometer; EQ5-U, EQ5 utility.

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  Figure 4.. Forest Plot of the Training Set Regression Coefficient Estimates (Points, Ordered from Smallest to Largest) and Related 95% Confidence Intervals (Bars) on the Log-odds Scale When Predicting Treatment Benefit as Defined by EQ5-T QoL Measures Using the Selected Multiple Logistic Regression Model. For continuous variables, estimates represent the change in the log-odds of treatment benefit associated with a 1 standard deviation unit increase from the mean. For categorical variables, the estimates represent the change in log-odds for treatment benefit when comparing the level listed on the left-hand side y-axis to its referent category. Negative (positive) values of the log-odds indicate a decreased (increased) probability of treatment benefit. Scaling and referent category information is provided in Appendix. Abbreviations: MI: myocardial infarction. LV: left ventricle. LVEF: LV ejection fraction. EQ5-T: EuroQol5 - health thermometer. EQ5-U: EuroQol - utility.

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  Figure 5.. Receiver Operating Characteristic (AUROC) Curves for the Training and Testing Datasets Using the Selected Multiple Logistic Regression Model. Abbreviation: AUROC, area under the receiver operating characteristic curve.