Importance: Olfactory dysfunction (OD) is a common and underdiagnosed condition that is associated with increased morbidity and mortality. However, existing smell tests can be costly and time intensive and can lack scalability.
Objective: To evaluate the performance of a novel, self-administered mobile application-based olfactory screening tool.
Design, setting, and participants: This diagnostic study was conducted at a tertiary academic medical center in the US between June 1 and December 31, 2024, to assess the performance of a novel olfactory test for the detection of OD. English-speaking individuals who were 18 years or older were recruited for the study.
Intervention: Completion of a 5-item, mobile application-based smell identification test. A subset of participants also completed a comparator test.
Main outcomes and measures: Diagnostic performance of a novel smell identification test in detecting OD compared with that of a comparator test. Secondary outcomes included correlation with subjective olfactory function.
Results: The study included 484 participants, 243 (50.2%) of whom were men. The mean (SD) age was 53.4 (18.5) years; 160 participants (33.1%) were 65 years or older. Seventy-four participants (15.3%) reported having subjective OD. Participants with self-reported OD had significantly lower novel test scores than those with normosmia (2.54 vs 3.50; mean difference, -0.96 [95% CI, -1.24 to -0.68]). At a cut point of less than 3, the novel test achieved an area under the curve of 0.87 (95% CI, 0.78-0.96), a sensitivity of 74% (95% CI, 51%-88%), and a specificity of 86% (95% CI, 72%-93%). Novel test scores correlated with comparator test scores (r = 0.74 [95% CI, 0.59-0.83]) as well as self-reported smell (r = 0.34 [95% CI, 0.25-0.41]), with acceptable internal consistency (Cronbach α = 0.70-0.71). Novel test scores declined with age, and women aged 18 to 29 years had higher scores than men in the same age group.
Conclusions and relevance: The findings of this diagnostic study suggest that the novel study test is a rapid and reliable olfactory screening tool that correlates well with validated smell tests and has potential for longitudinal screening of OD in the clinical setting.
Importance: Innovative clinical trials (CTs) are needed to address the rising incidence of head and neck squamous cell carcinoma (HNSCC). Despite adequate trial initiation, HNSCC CTs experience high failure rates, and the factors driving these trends remain unclear.
Objective: To assess the characteristics associated with failure (termination or withdrawal) in CTs for the treatment of HNSCC.
Design and setting: HNSCC CTs were identified on ClinicalTrials.gov from January 1, 2000, to December 31, 2024, and trial failures were defined as early termination or withdrawal. Trial characteristics were compared between failed CTs and completed CT controls. Data were analyzed from June to August 2025.
Main outcomes and measures: The primary outcome was trial failure. The association between failure and CT characteristics, including phase, enrollment, funding source, intervention type, and age-eligibility criteria, was analyzed using descriptive statistics and multivariable regression models.
Results: A total of 692 matched trials were analyzed, including 346 trial failures and 346 completed control trials. The overall leading reasons for failure were strategic decisions (defined as nonscientific, sponsor-driven choices; 102 trials [29.5%]) and poor recruitment (90 trials [26.0%]). The reasons for failure varied by trial characteristics. Strategic decisions were the predominant reason for failure in phase 1 trials, industry-sponsored trials, and immunotherapy and targeted therapy trials. In contrast, poor recruitment was a more common reason in later-phase trials, non-industry-sponsored trials, and trials investigating chemotherapy, radiation, chemoradiation, combination treatments, and supportive care. Temporal analysis revealed a growing failure rate among CTs since 2000. Increased log-transformed actual enrollment safeguarded against trial failure, whereas industry funding was an independent risk factor.
Conclusions and relevance: In this study, HNSCC CTs were terminated early or withdrawn for a variety of reasons, most commonly due to strategic decisions or poor recruitment. Careful attention to trial characteristics associated with early failure is needed to overcome new barriers to drug development and adapt trial design to common reasons for failure.

