A scoping assessment of dental services at designated head and neck cancer centres in Ontario, Canada.

BACKGROUND: Dentists serve a crucial role in managing treatment complications for patients with head and neck cancer, including post-radiation caries and oral infection. To date, dental services for head and neck cancer patients in Ontario, Canada have not been well characterized and considerable disparities in allocation, availability, and funding are thought to exist. The current study aims to describe and assess the provision of dental services for head and neck cancer patients in Ontario. METHODS: A mixed methods scoping assessment was conducted. A purposive sample of dentist-in-chiefs at each of Ontario's 9 designated head and neck cancer centres (tertiary centres which meet provincially-set quality and safety standards) was invited to participate. Participants completed a 36-item online survey and 60-minute semi-structured interview which explored perceptions of dental services for head and neck cancer patients at their respective centres, including strengths, gaps, and inequities. If a centre did not have a dentist-in-chief, an alternative stakeholder who was knowledgeable on that centre's dental services participated instead. Thematic analysis of the interview data was completed using a mixed deductive-inductive approach. RESULTS: Survey questionnaires were completed at 7 of 9 designated centres. A publicly funded dental clinic was present at 5 centres, but only 2 centres provided automatic dental assessment for all patients. Survey data from 2 centres were not captured due to these centres' lack of active dental services. Qualitative interviews were conducted at 9 of 9 designated centres and elicited 3 themes: (1) lack of financial resources; (2) heterogeneity in dentistry care provision; and (3) gaps in the continuity of care. Participants noted concerning under-resourcing and limitations/restrictions in funding for dental services across Ontario, resulting in worse health outcomes for vulnerable patients. Extensive advocacy efforts by champions of dental services who have sought to mitigate current disparities in dentistry care were also described. CONCLUSIONS: Inequities exist in the provision of dental services for head and neck cancer patients in Ontario. Data from the current study will broaden the foundation for evidence-based decision-making on the allocation and funding of dental services by government health care agencies.

Association of Household Income at Diagnosis With Financial Toxicity, Health Utility, and Survival in Patients With Head and Neck Cancer.

Importance: While several studies have documented a link between socioeconomic status and survival in head and neck cancer, nearly all have used ecologic, community-based measures. Studies using more granular patient-level data are lacking. Objective: To determine the association of baseline annual household income with financial toxicity, health utility, and survival. Design, Setting, and Participants: This was a prospective cohort of adult patients with head and neck cancer treated at a tertiary cancer center in Toronto, Ontario, between September 17, 2015, and December 19, 2019. Data analysis was performed from April to December 2021. Exposures: Annual household income at time of diagnosis. Main Outcome and Measures: The primary outcome of interest was disease-free survival. Secondary outcomes included subjective financial toxicity, measured using the Financial Index of Toxicity (FIT) tool, and health utility, measured using the Health Utilities Index Mark 3. Cox proportional hazards models were used to estimate the association between household income and survival. Income was regressed onto log-transformed FIT scores using linear models. The association between income and health utility was explored using generalized linear models. Generalized estimating equations were used to account for patient-level clustering. Results: There were 555 patients (mean [SD] age, 62.7 [10.7] years; 109 [20%] women and 446 [80%] men) included in this cohort. Two-year disease-free survival was worse for patients in the bottom income quartile (<$30 000: 67%; 95% CI, 58%-78%) compared with the top quartile (≥$90 000: 88%; 95% CI, 83%-93%). In risk-adjusted models, patients in the bottom income quartile had inferior disease-free survival (adjusted hazard ratio, 2.13; 95% CI, 1.22-3.71) and overall survival (adjusted hazard ratio, 2.01; 95% CI, 0.94-4.29), when compared with patients in the highest quartile. The average FIT score was 22.6 in the lowest income quartile vs 11.7 in the highest quartile. In adjusted analysis, low-income patients had 12-month FIT scores that were, on average, 134% higher (worse) (95% CI, 16%-253%) than high-income patients. Similarly, health utility scores were, on average, 0.104 points lower (95% CI, 0.026-0.182) for low-income patients in adjusted analysis. Conclusions and Relevance: In this cohort study, patients with head and neck cancer with a household income less than CAD$30 000 experienced worse financial toxicity, health status, and disease-free survival. Significant disparities exist for Ontario's patients with head and neck cancer.

Construct Validity of the EuroQoL-5 Dimension and the Health Utilities Index in Head and Neck Cancer.

OBJECTIVE: The objective of this study was to evaluate the construct validity of 2 health utility instruments-the EuroQoL-5 Dimension (EQ-5D) and the Health Utilities Index-Mark 3 (HUI-3)-and to compare them with disease-specific measures in patients with head and neck cancer. STUDY DESIGN: Prospective cross-sectional analysis. SETTING: Princess Margaret Cancer Centre. METHODS: Patients were administered the EQ-5D, HUI-3, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its head and neck cancer module (EORTC QLQ-H&N35), and the University of Washington Quality of Life Questionnaire (UWQoL). Several a priori expected relations were examined. The correlative and discriminative properties of the various instruments were examined. RESULTS: A total of 209 patients completed the 4 questionnaires. A significant ceiling effect was observed among EQ-5D responses (23% reported a maximum score of 1). The EQ-5D (rho = 0.79) and HUI-3 (rho = 0.60) had a strong correlation with the social-emotional domain of the UWQoL. The EQ-5D had a moderate correlation with the physical domain of the UWQoL (rho = 0.42), whereas the HUI-3 had a weak correlation (rho = 0.29). The EQ-5D and HUI-3 were able to distinguish among levels of health severity measured on the EORTC QLQ-C30 though not the QLQ-H&N35. Comparatively, the UWQoL was able to distinguish levels of disease severity on the EORTC QLQ-C30 and QLQ-H&N35. CONCLUSION: The results of this study demonstrate that disease-specific domains from head and neck quality-of-life instruments are not strongly correlated with the EQ-5D and HUI-3. Consideration should be put toward development of a disease-specific preference-based measure for health economic evaluation. LEVEL OF EVIDENCE: 4.

Rapid Development and Deployment of an Intensivist-Led Venovenous Extracorporeal Membrane Oxygenation Cannulation Program.

OBJECTIVES: To determine the safety and efficacy of a rapidly deployed intensivist-led venovenous extracorporeal membrane oxygenation cannulation program in a preexisting extracorporeal membrane oxygenation program. DESIGN: A retrospective observational before-and-after study of 40 patients undergoing percutaneous cannulation for venovenous extracorporeal membrane oxygenation in an established cannulation program by cardiothoracic surgeons versus a rapidly deployed medical intensivist cannulation program. SETTING: An adult ICU in a tertiary academic medical center in Camden, NJ. PATIENTS: Critically ill adult subjects with severe respiratory failure undergoing percutaneous cannulation for venovenous extracorporeal membrane oxygenation. INTERVENTIONS: Percutaneous cannulation for venovenous extracorporeal membrane oxygenation performed by cardiothoracic surgeons compared with cannulations performed by medical intensivists. MEASUREMENTS AND MAIN RESULTS: Venovenous extracorporeal membrane oxygenation cannulation site attempts were retrospectively reviewed. Subject demographics, specialty of physician performing cannulation, type of support, cannulation configuration, cannula size, imaging guidance, success rate, and complications were recorded and summarized. Twenty-two cannulations were performed by three cardiothoracic surgeons in 11 subjects between September 2019 and February 2020. The cannulation program rapidly transitioned to an intensivist-led and performed program in March 2020. Fifty-seven cannulations were performed by eight intensivists in 29 subjects between March 2020 and December 2020. Mean body mass index for subjects did not differ between groups (33.86 vs 35.89; p = 0.775). There was no difference in days on mechanical ventilation prior to cannulation, configuration, cannula size, or discharge condition. There was no difference in success rate of cannulation on first attempt per cannulation site (95.5 vs 96.7; p = 0.483) or major complication rate per cannulation site (4.5 vs 3.5; p = 1). CONCLUSIONS: There is no difference between success and complication rates of percutaneous venovenous extracorporeal membrane oxygenation canulation when performed by cardiothoracic surgeons versus medical intensivist in an already established extracorporeal membrane oxygenation program. A rapidly deployed cannulation program by intensivists for venovenous extracorporeal membrane oxygenation can be performed with high success and low complication rates.

The Edmonton Symptom Assessment System: A narrative review of a standardized symptom assessment tool in head and neck oncology.

OBJECTIVE: Symptom burden is common in head and neck cancer patients though it frequently remains undetected and untreated. The Edmonton Symptom Assessment System - revised version (ESAS-r) is a generic symptom scale deployed in many outpatient settings worldwide. The ESAS-r is meant to improve symptom detection and management. We sought to review the ESAS-r and its psychometric properties in a head and neck oncology population. METHODS: Narrative Review. RESULTS: Over the past 30 years, the ESAS-r has emerged as one of the most used symptom scales for cancer patients. Its psychometric properties in a heterogenous cancer population are well supported, proving to be reliable and valid in a variety of settings. The linking of ESAS-r scores with Ontario administrative health data has led to a detailed assessment of validity in head and neck cancer. The ESAS-r can discriminate between high and low levels of symptom burden and is responsive to change over time in this patient population. ESAS-r scores have also been shown to be a strong predictor of future emergency department use and unplanned hospitalization in head and neck cancer patients. CONCLUSIONS: The ESAS-r is reliable and valid in the head and neck cancer population and may serve as a useful clinical endpoint in research studies.

A cost-utility analysis comparing CT surveillance, PET-CT surveillance, and planned postradiation neck dissection for advanced nodal HPV-positive oropharyngeal cancer.

BACKGROUND: The cost utility of image-guided surveillance using computed tomography (CT) and positron emission tomography (PET)-CT to planned postradiation neck dissection (PRND) was compared for the management of advanced nodal human papillomavirus-positive oropharyngeal cancer following chemoradiation. METHODS: A universal payer perspective was adopted. A Markov model was designed to simulate four treatment approaches with 3-month cycles over a lifetime horizon: 1) CT surveillance, 2) standard PET-CT surveillance, 3) a novel PET-CT approach with repeat PET at 6 months postchemoradiation for equivocal responders, and 4) PRND. Parameters including probabilities of CT nodal progression/resolution, PET avidity, recurrence, and survival were obtained from the literature. Costs were reported in 2019 Canadian dollars and utilities were expressed in quality-adjusted life years (QALYs). Deterministic and probabilistic sensitivity analyses were performed to evaluate model uncertainty. RESULTS: PET-CT surveillance dominated CT surveillance and PRND in the base case scenario, and the novel PET-CT approach was the most cost-effective strategy across a wide range of variables tested in one-way sensitivity analysis. On probabilistic sensitivity analysis, novel PET-CT surveillance was the most cost-effective strategy in 78.1% of model iterations at a willingness-to-pay of $50,000/QALYs. Novel PET-CT surveillance resulted in a 49% lower rate of neck dissection compared with traditional PET-CT, and yielded an incremental benefit of 0.14 QALYs with average cost savings of $1309. CONCLUSIONS: Image-guided surveillance including PET-CT and CT are more cost effective than PRND. The novel PET-CT approach with repeat PET for equivocal responders was the dominant strategy and yielded both higher benefit and lower costs compared with standard PET-CT surveillance.

Elective neck dissection versus positron emission tomography-computed tomography-guided management of the neck in clinically node-negative early oral cavity cancer: A cost-utility analysis.

BACKGROUND: In early oral cavity cancer, elective neck dissection (END) for the clinically node-negative (cN0) neck improves survival compared with observation. This paradigm has been challenged recently by the use of positron emission tomography-computed tomography (PET-CT) imaging in the cN0 neck. To inform this debate, we performed an economic evaluation comparing PET-CT-guided therapy with routine END in the cN0 neck. METHODS: Patients with T1-2N0 lateralized oral tongue cancer were analyzed. A Markov model over a 40-year time horizon simulated treatment, disease recurrence, and survival from a US health care payer perspective. Model parameters were derived from a review of the literature. RESULTS: The END strategy was dominant, with a cost savings of $1576.30 USD, an increase of 0.055 quality-adjusted life years (QALYs), a net monetary benefit of $4303 USD, and a 0.22 life-year advantage. END was sensitive to variation in cost and utilities in deterministic and probabilistic sensitivity analyses. PET-CT became the preferred strategy when decreasing occult nodal disease to 18% and increasing the negative predictive value (NPV) of PET-CT to 89% in 1-way sensitivity analyses. In probabilistic sensitivity analysis, assuming a cost effectiveness threshold of $50,000 USD/QALY, END was dominant in 64% of simulations and cost effective in 69.8%. CONCLUSION: END is a cost-effective strategy compared with PET-CT in patients who have node-negative oral cancer. Although lower PET standardized uptake value thresholds would result in fewer false negatives and improved NPV, it is still uncertain that PET-CT would be cost effective, as this would likely result in more false positive tests.

Decision Modeling for Economic Evaluation in Otolaryngology-Head and Neck Surgery: Review of Techniques.

Decision making in health care is complex, and substantial uncertainty can be involved. Structured, systematic approaches to the integration of available evidence, assessment of uncertainty, and determination of choice are of significant benefit in an era of "value-based care." This is especially true for otolaryngology-head and neck surgery, where technological advancements are frequent and applicable to an array of subspecialties. Decision analysis aims to achieve these goals through various modeling techniques, including (1) decision trees, (2) Markov process, (3) microsimulation, and (4) discrete event simulation. While decision models have been used for decades, many clinicians and researchers continue to have difficulty deciphering them. In this review, we present an overview of various decision analysis modeling techniques, their purposes, how they can be interpreted, and commonly used syntax to promote understanding and use of these approaches. Throughout, we provide a sample research question to facilitate discussion of the advantages and disadvantages of each technique.

Predictors of surgical readmission, unplanned hospitalization and emergency department use in head and neck oncology: A systematic review.

OBJECTIVE: To identify predictors of unplanned hospitalization and emergency department (ED) use among head and neck oncology patients. METHODS: Peer reviewed publications were identified through a systematic search of MEDLINE, Embase and Cochrane CENTRAL. Studies describing a cohort of HNC patients that detailed predictors of unplanned hospitalization or ED use in risk-adjusted models were eligible for inclusion. The methodologic quality of included studies was assessed using the Quality In Prognostic Studies (QUIPS) tool and an adapted version of the GRADE framework. RESULTS: Of the 932 articles identified, 39 studies met our inclusion criteria with 31/39 describing predictors of surgical readmission and 10/39 describing predictors of ED use or unplanned hospitalization during radiation/chemoradiation treatment. Risk factors were classified into either 'patient-related', 'cancer severity' or 'process' factors. In the subset of studies looking at readmission following surgery wound complications (10/14 studies), presence of comorbidity (16/28 studies), low socioeconomic status (8/17 studies), cancer stage (9/14 studies), and prolonged hospital stay (7/18 studies) were the variables most frequently associated with readmission on multivariable analysis. Presence of comorbidity (6/10) and chemotherapy use (4/10) were more frequently associated with ED use and unplanned hospitalization. CONCLUSIONS: Several consistent predictors have been identified across a variety of studies. This work is a critical first step towards the development of readmission and ED prediction models. It also enables meaningful comparison of hospital readmission rates with risk adjustment in HNC patients.

Nonsurgical management of resectable oral cavity cancer in the wake of COVID-19: A rapid review and meta-analysis.

OBJECTIVE: Surgery is the preferred treatment modality for oral squamous cell carcinoma (OSCC). However, due to limited resources, re-assessment of treatment paradigms in the wake of the Coronavirus Disease 2019 (COVID-19) pandemic is urgently required. In this rapid review, we described contemporary oncological outcomes for OSCC using non-surgical modalities. METHODS: A systematic literature search was conducted for articles published between January 1, 2010 and April 1, 2020 on MEDLINE and Cochrane CENTRAL. Studies were included if they contained patients with OSCC treated with either neoadjuvant, induction, or definitive radiotherapy, chemotherapy, immunotherapy, or combination thereof, and an outcome of overall survival. RESULTS: In total, 36 articles were included. Definitive radiotherapy or chemoradiotherapy were the focus of 18 articles and neoadjuvant chemotherapy or chemoradiotherapy were the focus of the other 18 articles. In early stage OSCC, definitive radiotherapy, with or without concurrent chemotherapy, was associated with a significantly increased hazard of death compared to definitive surgery (HR: 2.39, 95% CI: 1.56-3.67, I2: 63%). The hazard of death was non-significantly increased with definitive chemoradiotherapy in studies excluding early disease (HR: 1.98, 95% CI: 0.85-4.64, I2: 84%). Two recent randomized control trials have been conducted, demonstrating no survival advantage to neoadjuvant chemotherapy. CONCLUSION: This review suggests that primary radiotherapy and chemoradiotherapy are inferior to surgical management for OSCC. Strategies for surgical delay warranting consideration are sparse, but may include several neoadjuvant regimens, recognizing these regimens may not offer a survival benefit over definitive surgery alone.

Mapping the University of Washington Quality of life questionnaire onto EQ-5D and HUI-3 indices in patients with head and neck cancer.

BACKGROUND: There is no mechanism to predict health utility (HU) values from the University of Washington Quality of Life Questionnaire (UWQoL) scores. We sought to develop a mapping algorithm capable of using UWQoL data to approximate HU scores. METHODS: Outpatients with head and neck cancer completed the UWQoL, EQ-5D, and the Health Utilities Index-Mark 3 (HUI-3). Results of the UWQoL were mapped onto both EQ-5D and HUI-3 scores using ordinary least-squares regression models. Two-part models were explored. The predictive power of the model was assessed using 10-fold cross-validation. RESULTS: A total of 209 patients were recruited. The reduced model converting UWQoL data into EQ-5D scores performed best (adjusted R2 = 0.628, root mean square error = 0.076). Both models demonstrated construct validity by discriminating between clinical indices of disease severity. CONCLUSIONS: The abovementioned algorithms enable researchers to perform health economic evaluations with existing UWQoL data in cases where prospectively collected HU values are not available.

Finding/identifying primaries with neck disease (FIND) clinical trial protocol: a study integrating transoral robotic surgery, histopathological localisation and tailored deintensification of radiotherapy for unknown primary and small oropharyngeal head and neck squamous cell carcinoma.

INTRODUCTION: Carcinomas of unknown primary site (CUP) of the head and neck have historically been worked up and managed heterogeneously. Failure to identify a primary site may result in large radiotherapy mucosal volumes. Transoral approaches such as Transoral Robotic Surgery (TORS) may improve the yield of identifying hidden primaries. We aim to assess the oncological and functional outcomes of a combined treatment approach with TORS and tailored radiotherapy. METHODS AND ANALYSIS: Twenty-five patients with metastatic squamous cell carcinoma to the neck without clinical or radiographic evidence of a primary site will be enrolled in a phase II trial. Patients will undergo a diagnostic or therapeutic approach with TORS based on specific algorithms incorporating tailored radiotherapy according to the location and laterality of the primary tumour. The primary outcome is to evaluate the out-of-field failure rate over a 2-year period. Secondary outcomes include identification rates, survival outcomes, patient reported outcomes and functional swallowing outcomes. ETHICS AND DISSEMINATION: The University Health Network Research Ethics Board approved this study (ID 15-9767). The results will be published in an open access journal. TRIAL REGISTRATION NUMBER: NCT03281499.

Unmet eye care needs among a homeless youth population.

OBJECTIVE: To assess the rate of visual impairment and quantify the unmet eye care needs within Toronto's homeless youth community. DESIGN: Prospective and cross sectional. PARTICIPANTS: Ninety randomly selected homeless youth aged 16-24 years. METHODS: From each of 9 participating homeless youth shelters and drop-in centres in Toronto, 10 English-speaking youths between ages 16 and 24 were randomly recruited. Information regarding sociodemographics, medical history, subjective visual acuity, and access to eye care was collected. Comprehensive visual screening and undilated direct fundoscopy were also performed. RESULTS: The median age of participants was 21 years (interquartile range = 19-23 years), and 62.2% were male. Most participants were homeless for less than 5 years (90%) and earning less than $500 monthly (57.8%). Despite 51.1% of participants having previously owned corrective lenses, only 20% of participants currently owned them when assessed/at study time. When analyzing the better-seeing eye, presenting visual acuity was 20/50 or worse in 18.9% (95% CI 10.8%-27.0%) of participants. Pinhole occlusion decreased the number to 2.2% (95% CI 0%-5.3%). The most common cause of visual impairment was uncorrected refractive error. Ocular pathology was observed in 8 participants. Compared to adults, youth have similar functional visual impairment (adults 24.0%, youth 18.9%) but less impairment uncorrectable by pinhole occlusion (adults 11.0%, youth 2.2%) and are less dissatisfied with their vision (adults 70.0%, youths 36.7%). Although a higher proportion of homeless youths have visited an eye specialist in the past year (adults 14.0%; youths 17.8%), neither group is visiting as frequently as the Canadian average (41%) (p < 0.01). CONCLUSIONS: Homeless youth have a high prevalence of visual impairment, even when living within a system of universal health insurance. Ongoing vision-screening programs, readily accessible free eye clinics, and particularly low-cost glasses may help address this need.

Comparison of Health State Utility Measures in Patients With Head and Neck Cancer.

IMPORTANCE: Accurate measurement of health state utilities (HU) is the cornerstone for cost-utility analyses and the valuation of quality of life for given health states. Current indirect methods of HU derivation lack face validity for patients with head and neck cancer. The appropriateness of these measures compared with direct methods, such as the standard gamble (SG), time trade-off (TTO), and visual analog scale (VAS), have not been assessed in this patient population. OBJECTIVE: To assess the convergent and construct validities of 5 different HU derivation methods in patients with head and neck cancer. DESIGN, SETTING, AND PARTICIPANTS: In a cross-sectional study, we recruited 100 consecutive patients with squamous cell carcinoma of the upper aerodigestive tract treated in the outpatient surgical oncology clinics of the Princess Margaret Cancer Centre from August 1 through October 31, 2014. We enrolled patients with a minimum of 3 months of follow-up after completion of treatment and no evidence of recurrent or metastatic disease. Participants completed SG, TTO, and VAS exercises, the EuroQoL instrument (EQ-5D), and the Health Utilities Index Mark 3 (HUI3) questionnaire. Data analysis was performed November 1 through December 15, 2014. EXPOSURES: Head and neck cancer and HU measures. MAIN OUTCOMES AND MEASURES: We assessed convergent validity of the 5 HU instruments through Spearman rank order correlation assessment. We determined construct validity through a priori hypotheses relating HU scores with clinical indexes of disease severity. RESULTS: The SG and TTO measures generated higher mean (SD) utility scores (0.91 [0.17] and 0.94 [0.14], respectively) than the VAS, EQ-5D, and HUI3 (0.76 [0.19], 0.82 [0.18], and 0.75 [025], respectively) (P < .001). The maximum score of 1.0 was reported in 60 of 99 cases (61%) for the SG and 75 of 99 cases (76%) for the TTO (a significant ceiling effect), in contrast to 5 of 99 cases (5%) for the VAS, 29 of 99 cases (29%) for the EQ-5D, and 6 of 99 cases (6%) for the HUI3. The VAS showed strong correlations with the EQ-5D (ρ = 0.63 [P < .001]) and HUI3 (ρ = 0.50 [P < .001]), and the HUI3 strongly correlated with the EQ-5D (ρ = 0.67 [P < .001]), whereas the SG and TTO generally correlated poorly with other HU measures (ρ range, 0.19-0.29) and with one another (ρ = 0.21 [P < .001]). The VAS, EQ-5D, and HUI3 were able to discriminate between participants who underwent salvage surgery compared with those who underwent primary surgery (mean [SD] utility scores, 0.48 [0.13] vs 0.76 [0.20] [P = .006], 0.62 [0.17] vs 0.83 [0.19] [P = .004], and 0.37 [0.29] vs 0.78 [0.22] [P = .004], respectively). Mean EQ-5D utility scores monotonically increased over time since completion of treatment (0.26 [P = .01]). The HUI3 yielded lower utility values for participants with laryngeal cancer (mean [SD], 0.59 [0.29]). The SG and TTO measures frequently generated utility scores that contradicted our hypothesized expectations. CONCLUSIONS AND RELEVANCE: Indirect HU measures may be more reflective of the health status of patients with head and neck cancer than direct measures. Current instruments lack face validity for attributes germane to this population.

Visual impairment and unmet eye care needs among homeless adults in a Canadian city.

IMPORTANCE: The ocular status of homeless populations remains largely unknown. Given that visual acuity has been shown to be heavily correlated with reduced well-being and decreased earning potential, findings of poor vision could have important health implications for people experiencing homelessness. OBJECTIVES: To assess the prevalence of visual impairment and to identify unmet eye care needs in an adult homeless population. DESIGN, SETTING, AND PARTICIPANTS: For this cross-sectional study, we recruited 100 homeless persons using a stratified random sampling technique from January to March 2014. Recruitment took place at 10 randomly selected adult shelters in Toronto, Ontario, Canada. All English-speaking persons older than 18 years of age were eligible to participate. Information was obtained on sociodemographic characteristics, ocular history, and subjective visual acuity. A comprehensive vision screening and an undilated retinal examination were performed for each participant. MAIN OUTCOMES AND MEASURES: Rates of functional visual impairment and prevalence of nonrefractive eye pathology. RESULTS: The median age of participants was 48 years (interquartile range, 36-56 years), and 62% were men. The median lifetime duration of homelessness was 12 months (interquartile range, 5-36 months). Based on the participants' presenting visual acuity, the age-standardized rate of visual impairment was 25.2% (95% CI, 16.7%-33.7%). After pinhole occlusion, this number decreased to 15.2% (95% CI, 7.7%-22.7%). In total, 13.0% (95% CI, 7.8%-20.0%) of participants experienced visual impairment secondary to a correctable refractive error. Although the major problem for this demographic was limited access to refractive correction, a large degree of nonrefractive pathology was also observed. Of all the participants, 34.0% (95% CI, 24.7%-43.3%) had 1 or more abnormal findings during the vision screening, and 8% (95% CI, 2.7%-13.3%) required urgent referral to an ophthalmologist. A large majority of participants (89.0%) indicated interest in accessing free eye examinations. CONCLUSIONS AND RELEVANCE: These data suggest that homeless adults have a high prevalence of visual impairment, even when living within a system of universal health insurance. Given the high level of interest in eye care among homeless persons, ongoing vision-screening programs and readily accessible free eye clinics may help address this need.