What questionnaires to use when measuring quality of life in sacral tumor patients: the updated sacral tumor survey.

BACKGROUND CONTEXT: Patient-reported outcomes are becoming increasingly important when investigating results of patient and disease management. In sacral tumor, the symptoms of patients can vary substantially; therefore, no single questionnaire can adequately account for the full spectrum of symptoms and disability.

PURPOSE: The purpose of this study is to analyze redundancy within the current sacral tumor survey and make a recommendation for an updated version based on the results and patient and expert opinions.

STUDY DESIGN/SETTING: A survey study from a tertiary care orthopedic oncology referral center was used.

PATIENT SAMPLE: The patient sample included 70 patients with sacral tumors (78% chordoma).

OUTCOME MEASURES: The following 10 questionnaires included in the current sacral tumor survey were evaluated: the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Item short form, PROMIS Pain Intensity short form, PROMIS Pain Interference short form, PROMIS Neuro-QOL v1.0 Lower Extremity Function short form, PROMIS v1.0 Anxiety short form, the PROMIS v1.0 Depression short form, the International Continence Society Male short form, the Modified Obstruction-Defecation Syndrome questionnaire, the PROMIS Sexual Function Profile v1.0, and the Stoma Quality of Life tool.

METHODS: We performed an exploratory factor analysis to calculate the possible underlying latent traits. Spearman rank correlation coefficients were used to measure to what extent the questionnaires converged. We hypothesized the existence of six domains based on current literature: mental health, physical health, pain, gastrointestinal symptoms, sexual function, and urinary incontinence. To assess content validity, we surveyed 32 patients, 9 orthopedic oncologists, 1 medical oncologist, 1 radiation oncologist, and 1 orthopedic oncology nurse practitioner with experience in treating sacral tumor patients on the relevance of the domains.

RESULTS: Reliability as measured by Cronbach alpha ranged from 0.65 to 0.96. Coverage measured by floor and ceiling effects ranged from 0% to 52% and from 0% to 30%, respectively. Explanatory factor analysis identified three traits to which the questionnaires that were expected to measure a similar construct correlated the most: mental health, physical function, and pain. Content validity index demonstrated low disagreement among patients (range: 0.10-0.18) and high agreement among physicians (range: 0.91-1.0) on the relevance of the proposed domains. Social health was identified by 50% of the commenting patients as an important yet missing domain.

CONCLUSIONS: The current sacral tumor survey is incomplete and time-consuming, and not all surveys are appropriate for the sacral tumor population. Our recommended survey contains less than half the questions and includes the newly recognized social health domain.