A systematic review of the use of the then-test for evaluating health-related quality of life in cancer patients.

BACKGROUND: The then-test, also known as the retrospective pre- and post-test design method, is a measurement used to evaluate response shift. The method requires patients to assess their previous health-related quality of life (HRQoL) and provide a retrospective judgement based on their current perspectives. The then-test, however, has been criticized for its reliability and validity. The objective of this systematic review is to summarize the current literature for the use of the then-test for evaluating HRQoL in cancer patients and account for potential response shift effects. METHODS: A literature search was conducted in May 2022 using MEDLINE, PubMed, and PsychINFO dated from 2005 to the time of the search. Studies were included if they (I) used the then-test and (II) involved a population of cancer patients (any cancer site). RESULTS: The literature search resulted in 16 studies, published between 2005 and 2020. All studies used the then-test to detect response shifts. The EORTC QLQ-C30 and EORTC QLQ-BR23 questionnaires were the most common assessments used to evaluate HRQoL. Of the 16 articles, 5 exclusively reported on breast cancer, 5 reported on prostate cancer, and the remaining included all cancer sites. Most studies looked at patients undergoing a combination of chemotherapy, radiotherapy, and hormonal therapy. The mean differences between the retrospective assessment at both 3 and 6 months were significant for various quality of life (QoL) dimensions. Patients in some studies recalled their pretreatment HRQoL (then-score) as better than the pretreatment baseline scores and others reported them as worse, both confirming the existence of a response shift. CONCLUSIONS: Our review demonstrates that the then-test measurement tool has been commonly used for the detection of response shift. Newer measures for response shift have become more accepted; the then-test, if used, should be used with caution considering its limitations and the emergence of more advanced methods.

Do patients enrolled in observational studies have better outcomes than non-participants? A retrospective analysis.

PURPOSE: Patients are commonly enrolled into clinical trials. It has been reported that these patients may have better outcomes than those not enrolled into the study. The reasoning from these improvements could be attributable to closer follow-up, better patient adherence, more health aware patients have, or reaction to observation such as the Hawthorne effect. METHODS: Three hundred forty-six patients were approached for a prospective skin toxicity study in adjuvant breast cancer radiotherapy (RT) but declined participation between January 2018 and July 2019 (non-trial group). They were retrospectively reviewed and patient, treatment and RT-related characteristics, as well as the occurrence of skin reactions, and the usage of topical treatments were collected. This was compared with a comparison cohort of 349 patients who were enrolled into a previously conducted prospective study (trial group). RESULTS: More patients in the trial group had conventional RT (CFRT) versus hypofractionated RT (HFRT). Data was further stratified and there was no significant difference in moist desquamation, topical antibiotic usage, dressing application, home care use, topical corticoid steroid use, and oral analgesic use. There was a significantly lower pain score in the group compared with the non-trial group in both HFRT and CFRT (OR = 0.091 and OR = 0.348, p < 0.0001). CONCLUSION: Our results demonstrated no differences other than pain between the trial group and non-trial group. Therefore, in this cohort, patients enrolled into an observational trial while undergoing adjuvant breast RT demonstrated similar experiences of skin reactions. There are challenges to assessing differences between these groups, as confounding is likely. Therefore, it is recommended for future studies to additionally assess the impact of study participation on outcomes such as quality of life, quality of care received, and/or anxiety levels.