Supplementary Material for: Increasing Temporal Trends in the Frequency of Methamphetamine-Associated Intracerebral Hemorrhage in the Philippines

Introduction: Methamphetamine is an established risk factor for intracerebral hemorrhage (ICH). Despite growing concerns over its abuse, particularly in the Philippines, region-specific data on its neurological consequences remain lacking. This study aimed to investigate the temporal trends in the frequency of methamphetamine-associated ICH (Meth-ICH) in the Philippines.
Methods: Consecutive patients presenting with ICH at the Philippine National Specialty Center for Brain and Spine Care between 2018 and 2024 were retrospectively included. Meth-ICH cases were identified through positive urine toxicology tests at the time of admission. Frequency counts of total ICH and Meth-ICH cases were used to calculate the proportion of Meth-ICH cases for each year. Temporal trends were assessed using the two-sided Cochrane-Armitage test for trend, and by analyzing absolute and relative changes in proportions.
Results: Of the 1,652 ICH patients included, 116 (7.02%) tested positive for methamphetamine. The proportion of Meth-ICH cases increased 11.82-fold over the seven-year study period, rising from 1.49% (4/268, 95% confidence interval [CI]: 1.15% to 1.83%) in 2018 to 17.58% (74/421, 95% CI: 14.04% to 21.12%) in 2024. Between 2018 and 2021, no significant changes were observed in the number and proportion of Meth-ICH cases. A non-significant upward trend was noted between 2021 and 2022, with a relative change in proportion of 67.30% (95% CI: -86.57% to 231.17%; p = .635). A significant increase in the proportion of Meth-ICH cases was seen between 2022 and 2024, with relative changes in proportion of 310.70% (95% CI: 213.70% to 407.70%; p = .003) from 2022 to 2023, and 100.80% (95% CI: 5.89% to 207.69%; p = .001) from 2023 to 2024.
Conclusion: There was an increasing trend in the frequency of Meth-ICH cases in the Philippines from 2018 to 2024, with a significant and sustained surge beginning in 2022. Comprehensive evidence-based public health strategies are urgently needed, particularly in regions with high rates of methamphetamine use.