Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Apr;44(4):345-354.
doi: 10.15537/smj.2023.44.4.20220664.

Systematic review and pooled analysis of randomized controlled trials in countries of the Gulf Cooperation Council (GCC): Methods and quality assessment

Khalid S Alraddadi  1 , Fayzah H Al-Adwani  1 , Rajaa M Al-Raddadi  1 , Sultan H Alamri  1 , Iman K Ramadan  1 , Ahmad A Mirza  1
Affiliations

Systematic review and pooled analysis of randomized controlled trials in countries of the Gulf Cooperation Council (GCC): Methods and quality assessment

Khalid S Alraddadi et al. Saudi Med J. 2023 Apr.

Abstract

Objectives: To describe variations in characteristics of randomized controlled trials conducted in the Gulf Cooperation Council (GCC) countries, and critically appraising the quality of design, conduct and analysis of the trials.

Methods: We carried out a systematically comprehensive electronic search of articles published between 1990 and 2018 and indexed in several databases: i) MEDLINE/PubMed, ii) EMBASE, iii) Cochrane Central Register of Controlled Trials (CENTRAL), iv) ClinicalTrials.gov, and v) World Health Organization International Clinical Trials Registry Platform. We summarized the overall risk of bias present in all analyzed studies using the Cochrane Collaboration risk of bias tool (CCRBT).

Results: A remarkable shift in numbers of publications from 2006 onwards was found. The largest number of publications were from Saudi Arabia and consisted of hospitals/clinics based studies. Lack of randomization was found in the majority of reports, and nearly three-fourth of the studies involved the use of intention-to-treat (ITT) principle. However, the proportion of adequately generated random sequence methods has increased yearly, and this increase accounted for a relatively large proportion over the latter half of the studied period (p<0.001), in contrast to the proportion of allocation concealment and blinding. Journal impact factor was significantly correlated with the quality of random sequence generation (r=0.145; p=0.014).

Conclusion: The randomization methods have gained more attention over the last 3 decades. Secondly, Journal impact factor can serve as an indicator of randomization quality. To mitigate the large rate of overall high risk of bias in GCC studies, high-quality trials must be considered by ensuring adequate allocation concealment and blinding methods. PROSPERO No. ID: CRD42022310331.

Keywords: Arab world; Clinical Trial; bias; systematic review.

PubMed Disclaimer

Figures

Figure 1
Figure 1
- Flow diagram of study selection.
Figure 2
Figure 2
- Number of randomized-controlled trials published between 1990 and 2018.
Figure 3
Figure 3
- Quality of randomized-controlled trials published between 1990 and 2018.
Figure 4
Figure 4
- Trend of overall risk of bias of randomized-controlled trials based on Cochrane Collaboration Risk of Bias Tool between 1990–2018 years.
See this image and copyright information in PMC

References

    1. Chung JH, Lee SW.. Assessing the quality of randomized controlled urological trials conducted by Korean medical institutions. Korean J Urol 2013; 54: 289–296. - PMC - PubMed
    1. Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS.. Evidence based medicine: what it is and what it isn’t. BMJ 1996; 312: 71–72. - PMC - PubMed
    1. Uetani K, Nakayama T, Ikai H, Yonemoto N, Moher D.. Quality of Reports on Randomized Controlled Trials Conducted in Japan: Evaluation of Adherence to the CONSORT Statement. Intern Med 2009; 48: 307–313. - PubMed
    1. You YN, Cho MR, Park JH, Park GC, Song MY, Choi JB, et al. . Assessing the quality of reports about randomized controlled trials of scalp acupuncture treatment for vascular dementia. Trials 2017; 18: 205. - PMC - PubMed
    1. Lim SM, Shin ES, Lee SH, Seo KH, Jung YM, Jang JE.. Tools for assessing quality and risk of bias by levels of evidence. J Korean Med Assoc 2011; 54: 419–429.

Publication types