Background
Scraping therapy is widely used in treating stage I and II essential hypertension in China. However, there has been no systematic evaluation of the efficacy of scraping therapy on blood pressure and sleep quality in stage I and II essential hypertension.

Search strategy
Seven electronic databases (PubMed, Scopus, Cochrane Library, Web of Science, EBSCO, China National Knowledge Infrastructure and Wanfang Data electronic databases) were searched from inception to December 2022. Based on the principle of combining subject words with text words, the search strategy was constructed around search terms for “scraping therapy,” “scraping,” “Guasha,” “Gua sha,” “hypertension,” and “high blood pressure” during the database searches.

Inclusion criteria
Randomized controlled trials (RCTs) were included if they recruited patients with stage I and II essential hypertension and included a scraping therapy intervention. The intervention group received antihypertensive drugs and scraping therapy, while the control group only took antihypertensive drugs.

Data extraction and analysis
Review Manager 5.4.0 and STATA 15.1 were used to enter all the relevant outcome variables to conduct the meta-analysis. The quality of the selected RCTs was assessed using the PEDro scale. The sensitivity analysis was carried out by iteratively excluding individual studies and repeating the analysis to determine the stability of the findings and identify any studies with greater influence on the outcome. Subgroup analysis was performed to find the source of heterogeneity. Funnel plots were used to evaluate the publication bias of included studies.

Results
Nine RCTs including 765 participants were selected. Meta-analysis showed that scraping therapy combined with medication had an advantage over the use of medication alone in lowering systolic blood pressure (mean difference [MD] = ?5.09, 95% confidence interval [CI] = ?6.50 to ?3.67, P < 0.001) and diastolic blood pressure (MD = ?2.66, 95% CI = ?3.17 to ?2.14, P < 0.001). Subgroup analysis showed that scraping therapy improved sleep quality in middle-aged patients with hypertension, but the efficacy was better in elderly patients (MD = ?7.91, 95% CI = ?8.65 to ?7.16, P < 0.001) than in middle-aged patients (MD = ?2.67, 95% CI = ?4.12 to ?1.21, P = 0.0003).

Conclusion
The available evidence indicates that scraping therapy has significant effects on patients with stage I and II hypertension, and it improves sleep quality for elderly patients with hypertension better than for middle-aged ones. Scraping therapy can be an adjunctive treatment for stage I and II essential hypertension. However, further high-quality studies are needed to verify its effectiveness and the best therapeutic strategies.

Key words: Scraping therapy, Essential hypertension, Efficacy, Blood pressure, Sleep quality, Systematic review, Meta-analysis