{'fraction_non_alphanumeric': 0.020895522388059702, 'fraction_numerical': 0.0, 'mean_word_length': 5.171779141104294, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Optimal Patient-specific Post-operative Surveillance for Vascular Surgery

We optimize post-operative surveillance schedules for patients who have undergone surgery to restore peripheral blood flow. Post-operative surveillance is performed using periodic duplex ultrasound tests to detect loss of blood flow before it poses a serious risk to the patient. Currently, tests are performed according to the same schedule for all patients, even though problems tend to occur early in some patient groups, and later in others. Moreover, the current schedule is not optimized to when failures occur. We provide a statistical procedure for estimating, from censored observations, the joint distribution of the time at which a problem can be detected in a follow-up visit, and the possibly later time at which the problem threatens the health of the patient. We then find optimal patient-specific follow-up schedules based on this estimation procedure, and compare its performance to the schedule currently in use.