Prevalence and adverse consequences of delayed diagnosis and misdiagnosis in thrombotic antiphospholipid syndrome. An observational cohort study and a review of the literature

OBIECTIVES: This study aims to prospectively evaluate the frequency and adverse consequences of diagnostic delay and misdiagnosis in a cohort of patients with thrombotic antiphospholipid syndrome (TAPS). In addition, a systematic review of the literature concerning the diagnostic delay and misdiagnosis of TAPS was carried out. METHODS: Patient enrollment occurred between 1999 and 2022. The study group was formed by TAPS patients whose diagnosis was delayed and those who were misdiagnosed. The control group was made up of patients who were timely and correctly diagnosed with TAPS. RESULTS: The literature review showed 42 misdiagnosed patients, 27 of them were in one retrospective cohort study and 15 in 13 case reports. One hundred sixty-one out of 189 patients (85.2%) received a timely, correct diagnosis of TAPS; 28 (14.8%) did not. The number of patients with diagnostic issues was significantly higher for the first period (1999–2010), and the number of patients with a correct diagnosis was significantly higher for the second one (2011–2022). When the clinical and laboratory characteristics of the patients with delayed diagnosis were compared with those with misdiagnosis, there was a significantly higher number of severe adverse consequences characterized by permanent disability or death in the latter group. The two most common types of misdiagnoses were systemic lupus erythematosus (6 cases, 46.1%) and cardiovascular diseases (4 cases, 30.8%). CONCLUSIONS: The study demonstrates that although knowledge about TAPS has improved over time, diagnostic delays and errors remains to be addressed as they are strongly associated to adverse consequences.