Revisiting sample size planning for receiver operating characteristic studies: a confidence interval approach with precision and assurance

Di Shu; Guangyong Zou

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arXiv · 2208.01614

Revisiting sample size planning for receiver operating characteristic studies: a confidence interval approach with precision and assurance

Di Shu·Guangyong Zou

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Abstract

Objectives: Estimation of areas under receiver operating characteristic curves (AUCs) and their differences is a key task in diagnostic studies. We aimed to derive, evaluate, and implement simple sample size formulas for such studies with a focus on estimation rather than hypothesis testing. Materials and Methods: Sample size formulas were developed by explicitly incorporating pre-specified precision and assurance, with precision denoted by the lower limit of confidence interval and assurance denoted by the probability of achieving that lower limit. A new variance function was proposed for valid estimation allowing for unequal variances of observations in the disease and non-disease groups. Performance of the proposed formulas was evaluated through simulation. Results: Closed-form sample size formulas were obtained. Simulation results demonstrated that the proposed formulas produced empirical assurance probability close to the pre-specified assurance probability and empirical coverage probability close to the nominal 95%. Real-world worked examples were presented for illustration. Conclusions: Sample size formulas based on estimation of AUCs and their differences were developed. Simulation results suggested good performance in terms of achieving pre-specified precision and assurance probability. An online calculator for implementing the proposed formulas is openly available at https://dishu.page/calculator/.

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Di Shu, Guangyong Zou. 2022-08-02. Revisiting sample size planning for receiver operating characteristic studies: a confidence interval approach with precision and assurance. https://arxiv.org/abs/2208.01614

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