Determinants of thrombocytopenia in critically ill patients: a systematic review and meta-analysis

Thrombocytopenia frequently occurs in critically ill patients and is associated with adverse clinical outcomes in the intensive care unit (ICU). Although numerous studies have explored potential contributors, the factors associated with the development of thrombocytopenia in critically ill populations have not been consistently summarized. This study aimed to synthesize available evidence and identify determinants associated with thrombocytopenia in critically ill patients.

A systematic search of PubMed, Embase, Web of Science, the Cochrane Library, CNKI, Wang fang and VIP were performed from database inception to 20 January 2026. Observational studies reporting factors associated with thrombocytopenia in critically ill patients were considered eligible. Two reviewers independently screened studies and extracted relevant data. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa Scale (NOS). Meta-analysis was conducted using Stata15 software, and pooled estimates were calculated using a random-effects model.

A total of 13 cohort studies involving 27,147 critically ill patients were included, among whom 4,820 developed thrombocytopenia. The pooled analysis indicated that bleeding was associated with a higher occurrence of thrombocytopenia (OR = 3.49, 95% CI: 1.70-7.19). A similar association was observed for sepsis (OR = 2.32, 95% CI: 1.74-3.09). Impaired liver function was also linked to an increased likelihood of thrombocytopenia (OR = 1.55, 95% CI: 1.14-2.11). In addition, a Simplified Acute Physiology Score (SAPS) < 20 showed a modest association with thrombocytopenia (OR = 1.09, 95% CI: 1.05-1.14).

Bleeding, sepsis, impaired liver function, and lower SAPS scores were associated with a higher likelihood of thrombocytopenia among critically ill patients. These findings highlight several clinical conditions that frequently accompany platelet decline in ICU settings and may assist clinicians in identifying patients who require closer monitoring. Additional prospective research may help clarify the underlying mechanisms and further define the clinical implications of these associations.