Objectives:
Does face mask use reduce risk of COVID-19 infection?

Study design:
This review article included 4 articles with a total of 7,688 participants.
There was no publication bias.

Results and conclusions:   
The investigators found that face mask use significantly reduced risk of COVID-19 infection with 88% [pooled RR = 0.12, 95% CI = 0.06 to 0.27, p  0.001, I2 = 43.3%, p = 0.152].
Sensitivity analysis showed no significant changes in the pooled RR.

Objectives:
What is the safety of dihydroartemisinin-piperaquine (DHA-PQ) compared to artemether-lumefantrine (AL) for the treatment of uncomplicated P. falciparum malaria among children in Africa?

Study design:
This review article included 18 studies involving 10,498 African children with uncomplicated P. falciparum malaria.

Objectives:
What are the household secondary attack rates (SARs) between different variants of COVID-19 and between unvaccinated cases and vaccinated cases?

Study design:
This review article included 126 total studies representing 1,437,696 contacts from 35 countries from June 18, 2021 to January 7, 2022.

Objectives:
Does postoperative coffee or caffeine consumption causally reduce risk of postoperative ileus (POI) in patients undergoing elective colorectal surgery?

Study design:
This review article included 4 RCTs with 312 subjects.

Results and conclusions:

Objectives:
What the incidence rate of myocarditis after RNA vaccines?

Study design:
This review article included 7 studies with a total of 17,704,413 subjects vaccinated with the 2 doses of RNA vaccines for coronavirus, of which 627 cases of confirmed myocarditis.

There was significant heterogeneity between results.
The meta-regression analysis excluded mean age, region, number of cases or number of people included as sources of heterogeneity.
The Egger test excluded the small-study [p = 0.19].

Objectives:
Does a higher intake of dietary antioxidants (like vitamin C and E, β-carotene, zinc, anthocyanins, lutein) reduce risk of Parkinson's disease (PD)?

Objectives:
Severe hypertension in pregnancy is a hypertensive crisis that requires urgent and intensive care due to its high maternal and fetal mortality. However, there is still a conflict of opinion on the recommendations of antihypertensive therapy.

What are the optimal blood pressure (BP) levels to prevent severe hypertension in pregnant women with nonsevere hypertension?

Objectives:
Does a high olive oil consumption reduce cancer risk?

Study design:
This review article included 37 case-control studies with 17,369 cases (persons with cancer) and 28,294 controls (persons without cancer) and 8 cohort studies with 12,461 incident cases among 929,771 subjects (participants).

Objectives:
Does a high serum vitamin D level reduce risk of latent tuberculosis infection?

Study design:
This review article included 2 case-control studies and 3 cohort studies with a total of 1,516 subjects, comprising 117 latent tuberculosis infection (LTBI) patients.
Diagnosis of LTBI in all studies was based upon QFN-GIT, IGRAs and/or TST.
2 case-control and 3 cohort studies were considered as high quality.

Objectives:
There is some evidence regarding the positive effects of ginger supplementation on metabolic profile in patients with type 2 diabetes (T2DM). However, they are conflicting and therefore, this review article has been conducted. 

Does ginger supplementation improve metabolic profile (FBS, HbA1c, TC, TG, LDL, HDL, SBP and DBP) in patients with type 2 diabetes?

Study design:
This review article included 10 RCTs.