Strengths and Limitations
stroke, Stroke
STROKE, SECONDARY, RECRUITMENT, STROKE
The IMPROVE Stroke Care trial has several strengths. First, the STEP intervention package was created based on potential causes of China’s low rate of reperfusion therapy, as well as incorporating some successful practices from other countries. Second, it was built on previous observational data and the organization of the National Registry Program Chinese Stroke Center Alliance,This study also has several limitations. First, the rate of reperfusion therapy and the intraclass correlation coefficient are higher than those estimated in the sample size estimation stage. However, the final sample size was much larger than the planned sample size because of the increasing enrollment volumes of participating hospitals in clinical practice and the continuous recruitment design, which made the trial well powered to detect the current difference. Second, the COVID-19 pandemic slowed enrollment during the last period of the trial, which increased the imbalance between the intervention and control period and may also have introduced enrollment bias. However, the baseline characteristics were largely comparable. The COVID-19 pandemic led to difficulties in the implementation of the intervention, which may also have impaired the intervention effect. Third, the complex intervention included many components (eg, workflow reconstruction, toolkits, technical trainings, and workshops) that may not have been well received and fully implemented at all sites, especially at tertiary hospitals, or not implemented for a sufficient duration to take effect. On the basis of the survey after the intervention, a single call activation of the stroke team was implemented in only approximately 75% of hospitals (73% in tertiary vs 80% in secondary hospitals), stroke-specific order sets were used in only 77% (72% in tertiary vs 83% in secondary hospitals), and a weekly or biweekly improvement meeting was held in 85.4% (78% in tertiary vs 89% in secondary hospitals). Fourth, the effect of intervention was seen in secondary hospitals. However, this result was drawn from the post hoc subgroup analysis without prespecified sample size calculation or adjustment for multiple subgroup tests, and the interaction 