Incidence and risk factors of venous thromboembolism in patients with amyotrophic lateral sclerosis: a systematic review and meta-analysis.

Aims: This systematic review and meta-analysis aimed to determine the annual incidence rate of venous thromboembolism (VTE) and identify risk factors of VTE in amyotrophic lateral sclerosis (ALS) patients.

Methods: A comprehensive search of three databases was conducted up to April 8, 2024, to identify longitudinal studies reporting VTE incidence in ALS patients. The included studies were either prospective or retrospective, following up with ALS patients. Quality assessment was performed using the NIH tool for observational cohort studies. Meta-analysis was conducted using Open Meta Analyst, employing a random-effect model. Subgroup, Meta-regression, and sensitivity analyses were also carried out.

Results: Our analysis included eight studies comprising a total of 26,758 ALS patients that met the inclusion criteria. The pooled annual incidence of VTE across all studies was found to be 22 cases per 1,000 person-year (95% CI = 18 to 27). Subgroup analysis revealed that the annual incidence of VTE in males was 19 cases per 1,000 person-year (95% CI = 15 to 22), while in females, it was 20 cases per 1,000 person-year (95% CI = 16 to 25). Leave-one-out analysis demonstrated that the incidence ranged from 21 to 28 cases per 1,000 person-year when excluding each study individually. Meta-regression analysis did not find a significant association between age and the risk of VTE (P = 0.079). Based on the included studies, risk factors of VTE in ALS patients included a history of VTE, non-invasive ventilation, immobility, and decreased functional status.

Conclusion: Patients with ALS face a higher risk of developing VTE compared to individuals of the same age. These findings underscore the importance of implementing preventive measures and closely monitoring VTE in ALS patients.