Development of a patient-reported questionnaire for collecting toxicity data following prostate brachytherapy
Received 15 May 2009; received in revised form 28 April 2010; accepted 6 May 2010. published online 21 June 2010. Corrected Proof
Abstract
Purpose
To improve a questionnaire used to collect patient-reported outcomes from patients with early stage prostate cancer treated with brachytherapy. A secondary aim was to adapt the Late Effects of Normal Tissue (LENT) subjective toxicity questionnaire for use to collect Common Terminology Criteria for Adverse Events (CTCAE) data, the current preferred platform for assessing radiation toxicity.
Materials and methods
Three hundred and seventy-seven patients were treated with permanent iodine-125 seed implant brachytherapy for early prostate cancer. Toxicity data were collected before and at nine time points post-treatment (0–36months). Compliance rates for patients completing individual items and item-subsection correlation coefficients were calculated. A factor analysis was carried out to analyse responses to the questionnaire and identify less informative questions, which could be removed. Cronbach’s α coefficient was used to measure reliability.
Results
Two thousand one hundred and eighty-eight questionnaires were analysed. There was poor compliance for questions specifically relating to operations and bowel medication. We found that the division of the questionnaire into subsections based on anatomical site was reasonable and that certain items could be safely removed. The high mean value for Cronbach’s α across all questionnaires (0.752; 95% CI: 0.726–0.779) indicated that the questionnaire was reliable. Fifteen of the 44 questions were removed from the original questionnaires. Questions on urinary incontinence severity, management of urinary and bowel incontinence, effects of reduced flow of urine and the effects of symptoms on activity of daily living and change in sexual function were required to adapt the LENT subjective questionnaire for use to collect CTCAE data.
Conclusions
A questionnaire, validated over 6years to collect LENT subjective data were adapted and is a reliable approach for collecting CTCAE data after prostate brachytherapy.
cMedical Statistics, The Christie NHS Foundation Trust, Manchester, UK
Corresponding author. Address: School of Cancer & Enabling Sciences, University of Manchester, c/o The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, United Kingdom.
ABSTRACT
months). Compliance rates for patients completing individual items and item-subsection correlation coefficients were calculated. A factor analysis was carried out to analyse responses to the questionnaire and identify less informative questions, which could be removed. Cronbach’s α coefficient was used to measure reliability.