Objective: To determine if the level of self-reported physical activity 1 month after deep vein thrombosis (DVT) is associated with the risk of post-thrombotic syndrome (PTS) in the first 2 years post-DVT.
Design: Prospective cohort study.
Setting: Multicenter study (8 hospitals).
Participants: Patients presenting with objectively diagnosed acute DVT to 8 hospitals in Quebec and Ontario, Canada.
Assessment of risk factors: We used validated questionnaires to measure physical activity (Godin questionnaire) and venous disease severity [generic physical quality of life (SF-36 PCS scale) or VEINES-QOL]. We adjusted for potential confounding effects of age, sex, and body mass index. We used multiple imputation to account for missing data.
Main outcome measures: Post-thrombotic syndrome (validated Villalta scale).
Results: For the 387 patients enrolled, univariate analysis suggested no association between 1-month activity and risk of PTS. After adjusting for missing data and potential confounders, there was no evidence of a trend toward increasing risk of PTS with increasing physical activity [1.65 (95% confidence interval, 0.87-3.14) for mild-moderate activity and 1.35 (95% confidence interval, 0.69-2.67) for high activity]. The results were similar when PTS was dichotomized as none/mild versus moderate/severe. Finally, patients with PTS had lower levels of activity at 2 years post-DVT.
Conclusions: The level of self-reported exercise in the first month post-DVT is not associated with an increased risk of PTS in the first 2 years after DVT. Post-thrombotic syndrome is associated with decreased levels of physical activity 2 years after DVT.