Table 1

Characteristics of included studies and the factors associated with adequate reporting of included studies (≥50% items were completely reported per article)

FactorsStudies (n (%*))Adequately reported studies (n (%)) Prevalence ratio (95% CI)Percentage of completely reported items per article
(median
(IQR))
Refer to systematic reviews (n (%))
Total497 (100)155 (31.0)36 (23–55)78 (15.7)
Affiliation(s) of the first author
 Palestine354 (71.2)99 (28.0)Reference36 (22–50)48 (13.6)
 Regional29 (5.80)6 (20.7)0.7 (0.4 to 1.5)28 (23–46)6 (20.7)
 International114 (22.9)50 (43.9) 1.6 (1.2 to 2.0) 46 (27–64)24 (21.1)
Collaborations
 The same Palestinian institution87 (17.5)12 (13.8)Reference23 (14–36)9 (10.3)
 Different Palestinians institutions149 (30.0)43 (28.9) 2.1 (1.2 to 3.8) 36 (23–54)15 (10.1)
 Palestinian and regional institutions30 (6.00)9 (30.0) 2.2 (1.0 to 4.6) 41 (23–50)5 (16.7)
 Palestinian and international institutions231 (46.5)91 (39.4) 2.9 (1.7 to 5.0) 43 (27–59) 49 (21.2)
Type of the study question
 Prevalence/association360 (72.4)125 (34.7)Reference41 (23–55)55 (15.3)
 Aetiology/risk factors25 (5.0)8 (32.0)0.9 (0.5 to 1.7)41 (36–54)0 (0.00)
 Diagnosis10 (2.0)0 (0.00)20 (15–33)3 (30.0)
 Therapeutic/intervention60 (12.1)12 (20.0) 0.6 (0.3 to 0.97) 32 (18–41) 16 (26.7)
 Prognosis16 (3.2)7 (43.8)1.3 (0.7 to 2.2)46 (41–56)1 (6.3.0)
 Others (case report)26 (5.2)3 (11.5) 0.3 (0.1 to 0.97) 35 (25–44)3 (11.5)
Study design
 Cross-sectional372 (74.8)121 (32.5)Reference36 (23–55)60 (16.1)
 Systematic review4 (0.8)2 (50.0)1.5 (0.6 to 4.1)44 (33–57)0 (0.00)
 RCTs8 (1.6)0 (0.00)20 (19–29) 4 (50.0)
 Non-RCTs8 (1.6)0 (0.00)18 (12–25)2 (25.0)
 Cohort36 (7.2)15 (41.7)1.3 (0.9 to 1.9)46 (32–55)7 (19.4)
 Case–control43 (8.7)14 (32.6)1.0 (0.6 to 1.6)46 (25–50)2 (4.7.0)
 Case reports/series26 (5.2)3 (11.5) 0.4 (0.1 to 1.0) 35 (25–44)3 (11.5)
Funding sources
 Not reported/unclear341 (68.6)87 (25.5)Reference33 (23–50)47 (13.8)
 Local (governmental/ industry/ institutional)49 (9.90)16 (32.7)1.3 (0.8 to 2.0)41 (23–55)11 (22.4)
 International and NGOs107 (21.5)52 (48.6) 1.9 (1.5 to 2.5) 46 (30–66)20 (18.7)
Reporting guidelines
 STROBE439 (88.3)150 (34.2)Reference41 (23–55)66 (15.0)
 PRISMA4 (0.80)2 (50.0)1.5 (0.54 to 3.9)44 (33–57)0 (0.00)
 CONSORT16 (3.20)0 (0.00)20 (12–28) 6 (37.5)
 CARE26 (5.20)3 (11.5) 0.3 (0.1 to 0.99) 35 (25–44)3 (11.5)
 STARD11 (2.20)0 (0.00)20 (17–33)3 (27.3)
 TRIPOD1 (0.20)0 (0.00)32 (32–32)0 (0.00)
Publication year
 200568 (13.7)6 (8.80)Reference23 (14–36)4 (5.90)
 2005–2010164 (33.0)49 (29.9) 3.4 (1.5 to 7.5) 36 (23–50)22 (13.4)
 2010265 (53.3)100 (37.7) 4.3 (2.0 to 9.3) 41 (23–55) 52 (19.6)
Number of authors per article
 Single51 (10.3)7 (13.7)Reference27 (18–36)6 (11.8)
 2–3134 (27.0)36 (26.9)2.0 (0.9 to 4.1)36 (23–50)14 (10.4)
 4–6227 (45.7)75 (33.0) 2.4 (1.2 to 4.9) 41 (23–55)35 (15.4)
 7–1057 (11.5)23 (40.4) 2.9 (1.4 to 6.3) 46 (27–63)15 (26.3)
 More than 1028 (5.60)14 (50.0) 3.6 (1.7 to 8.0) 48 (30–73)8 (28.6)
Impact factor of the journal
 No impact factor191 (38.4)54 (28.3)Reference36 (23–50)29 (15.2)
 Less than 2146 (29.4)39 (26.7)0.9 (0.7 to 1.3)32 (18–50)19 (13.0)
 2 or more160 (32.2)62 (38.8) 1.4 (1.0 to 1.8) 42 (31–59)30 (18.8)
Number of citations per article
 None164 (33.0)46 (28.0)Reference36 (23–51)28 (17.1)
 Less than 5190 (38.2)59 (31.1)1.1 (0.8 to 1.5)36 (23–53)34 (17.9)
 5 or more143 (28.8)50 (35.0)1.3 (0.9 to 1.7)41 (23–55)16 (11.2)
Referred to previous relevant systematic reviews
 Yes78 (15.7)30 (38.5)Reference44 (31–67)
 No419 (84.3)125 (29.8)1.3 (0.9 to 1.8)36 (23–50)
  • *The denominator of the percentage is the total included studies (n=497).

  • †The denominator of the percentage is the number of studies in each subgroup (row subgroup).

  • ‡Adequately reported means≥50% items were completely reported per article.

  • Bold means significant (p value of Fisher’s exact test of statistical significance was <0.05).

  • CARE, CAse REport; CONSORT, CONsolidated Standards of Reporting Trials; NGO, non-governmental organisation; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; RCT, randomised controlled trial; STARD, Standards for Reporting of Diagnostic Accuracy; STROBE, STrenghtening the Reporting of Observational studies in Epidemiology; TRIPOD, Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis.