PATIENT'S PREFERENCE FOR SURGERY OR STEREOTACTIC ABLATIVE RADIOTHERAPY FOR STAGE I NON-SMALL CELL LUNG CANCER: A CONJOINT ANALYSIS OF TREATMENT DECISIONS

Purpose: The aim of this study was to investigate what treatment options thoracic oncologists of different specialties choose for different patient cases, and how these decisions are influenced by several patient characteristics and patient's treatment preference.

Methods: A conjoint analysis study was carried out among pulmonologists, surgeons and radiation oncologists, all of whom are routinely involved in the treatment of lung cancer. Clinicians were asked to indicate if they would advise surgery or stereotactic ablative radiotherapy (SABR) for hypothetical patient cases with stage I NSCLC. Cases varied on five patient characteristics: age (40y vs 75y), Chronic Obstructive Pulmonary Disease Global Initiative for Chronic Obstructive Lung Disease score (COPD GOLD score ≤I vs II), Charlson co morbidity index (0 vs 3+), World Health Organisation (WHO) performance status (≤1 vs 2) and preference of the patient (surgery vs SABR). Using a fractional factorial design we constructed 16 cases. Clinicians also indicated how certain they were about their decision on a 7-point Likert scale. Multilevel logistic regression analysis was used to determine the association of patient characteristics with treatment decisions of physicians. In addition, the relative importance was calculated.

Results: In total 249 clinicians were invited using records of professional associations in the Netherlands. Nearly half of them (n=126) completed the survey (73 pulmonologists, 17 surgeons and 36 radiation oncologists). Surgeons recommended SABR in 6.2 out of 16 cases (SD=4.1), radiation oncologists recommended SABR in 9.9 out of 16 cases (SD=2.9) and pulmonologists in 8.6 out of 16 cases (SD=2.8). All five patient characteristics contributed significantly (P < 0.0001) to clinicians’ decisions. Interaction effects were found between patients’ age and patients’ treatment preference, COPD and WHO, COPD and patients’ treatment preference and COPD and comorbidity (P ≤  0.05).

Conclusions: Despite current guidelines, a large variability is observed among thoracic oncologists in their treatment decisions for stage I NSCLC. Attributes most important to clinicians when advising a treatment option are comorbidity, WHO score and patients’ age, with patient preference playing only a marginal role.