OBJECTIVES: Hospitals are a favorable environment for early health technology assessment (HTA) and cross-over designs are ideally suited for this. For example, young children who cannot tolerate eye examinations may require examination under anesthesia (EUA) in an operating room. Examination under chloral hydrate sedation (EUS) in an outpatient clinic may be a convenient and cost-effective alternative.  The objective was to determine the incremental cost of EUS compared to EUA per additional successful procedure gained from a societal perspective. METHODS: A cost-effectiveness analysis was conducted using a retrospective cross-over cohort of 80 children that had both EUS and EUA.  Direct costs included health professional services, supplies and equipment and indirect costs included parent productivity losses.  Outcomes included the number of successful procedures and adverse events (AEs).  One-way and probabilistic sensitivity analyses were conducted. RESULTS: The mean cost per patient was $406 (95% CI $401, $411) for EUS and $1,135 (95% CI $1,125, $1,145) for EUA. The mean number of successful procedures per patient was 1.39 (95% CI 1.34, 1.42) for EUS and 2.06 (95% CI 2.02, 2.11) for EUA. EUS was $729 less costly on average than EUS but resulted in 0.68 fewer successful procedures per child.  Three AEs occurred in 2 EUS patients compared to 1 in the EUA group. The result was robust to varying the cost assumptions. When failed EUS were assumed to be completed as EUA, the mean cost of EUS increased to $586 (95% CI $438, $735), but remained significantly less than EUA. CONCLUSIONS: Hospitals pressured to rationalize care create opportunities for early HTA. Cross-over designs are promising for assessments of costs and effectiveness of emerging technologies because patients serve as their own control. This study demonstrated significant savings when ophthalmologic exams were carried out in a hospital outpatient clinic, albeit with slightly fewer procedures completed.