Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Quality analysis of randomized controlled trials in the International Journal of Impotence Research: quality assessment and relevant clinical impact


The quality of randomized controlled trials (RCTs) reported in the International Journal of Impotence Research (IJIR) was analyzed. The original articles that reported RCTs and were published in the IJIR in 1997–2014 were identified by PubMed. Their methodological quality was assessed using the Jadad scale, van Tulder scale and Cochrane Collaboration Risk of Bias Tool. The review period was divided into three periods: early (1997–2002), mid (2003–2008) and late (2009–2014). The effect of study subject and presence of Institutional Review Board approval, intervention, funding and adequate allocation concealment on RCT quality was assessed. The frequency of RCT publication in the IJIR did not change over the 19-year study period. Numbers of low risk of bias articles were 1 (3.0%), 2 (4.4%) and 4 (12.1%) in the early, mid and late periods in Cochrane Collaboration Risk of Bias Tool (P=0.04). High-quality low risk of bias RCT publication frequency increased over time. Intervention and funding significantly influenced RCT quality. Thus, the number of RCTs published in the IJIR over time has remained constant while their quality has improved. Ongoing efforts to expand the numbers of RCTs and further improve the quality of research published by the IJIR will improve clinical practice.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 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.

    Article  Google Scholar 

  2. 2

    Altman DG . Better reporting of randomised controlled trials: the CONSORT statement. BMJ 1996; 313: 570–571.

    CAS  Article  Google Scholar 

  3. 3

    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.

    Article  Google Scholar 

  4. 4

    Jackson JL, Srinivasan M, Rea J, Fletcher KE, Kravitz RL . The validity of peer review in a general medicine journal. PLoS One 2011; 6: e22475.

    CAS  Article  Google Scholar 

  5. 5

    Moher D, Hopewell S, Schulz KF, Montori V, Gøtzsche PC, Devereaux PJ et al. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. Int J Surg 2012; 10: 28–55.

    Article  Google Scholar 

  6. 6

    Chung W, Lee KW, Hwang IH, Lee DH, Kim SY . Quality assessment of randomized controlled trials in the journal of the korean academy of family medicine. Korean J. Fam Med 2009; 30: 626–631.

    Google Scholar 

  7. 7

    Jadad AR, Cook DJ, Jones A, Klassen TP, Tugwell P, Moher M et al. Methodology and reports of systematic reviews and meta-analyses: a comparison of Cochrane reviews with articles published in paper-based journals. JAMA 1998; 280: 278–280.

    CAS  Article  Google Scholar 

  8. 8

    Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Gavaghan DJ et al. Assessingthe quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials 1996; 17: 1–12.

    CAS  Article  Google Scholar 

  9. 9

    van Tulder M, Furlan A, Bombardier C, Bouter L . Updated method guidelines for systematic reviews in the cochrane collaboration back review group. Spine 2003; 28: 1290–1299.

    PubMed  Google Scholar 

  10. 10

    Higgins JP, Green S, eds. Cochrane handbook for systematic reviews of interventions. Ver. 5.1.0. The Cochrane Collaboration. 2011. Available at Accessed 7 January 2011.

  11. 11

    Sutton AJ, Cooper NJ, Jones DR . Evidence synthesis as the key to more coherent and efficient research. BMC Med Res Methodol 2009; 9: 29.

    Article  Google Scholar 

  12. 12

    Gill P, Dowell AC, Neal RD, Smith N, Heywood P, Wilson AE . Evidence based general practice: a retrospective study of interventions in one training practice. BMJ 1996; 312: 819–821.

    CAS  Article  Google Scholar 

  13. 13

    Scales CD Jr, Norris RD, Keitz SA, Peterson BL, Preminger GM, Vieweg J et al. A critical assessment of the quality of reporting of randomized, controlled trials in the urology literature. J Urol 2007; 177: 1090–1094.

    Article  Google Scholar 

  14. 14

    Jo JK, Chung JH, Kim KS, Lee JW, Lee SW . Randomized controlled trials in the journal of sexual medicine: a quality assessment and relevant clinical impact. J Sex Med 2014; 11: 894–900.

    Article  Google Scholar 

  15. 15

    Chalmers TC, Celano P, Sacks HS, Smith H Jr. . Bias in treatment assignment in controlled clinical trials. N Engl J Med 1983; 309: 1358–1361.

    CAS  Article  Google Scholar 

  16. 16

    Schulz KF, Chalmers I, Hayes RJ, Altman DG . Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials. JAMA 1995; 273: 408–412.

    CAS  Article  Google Scholar 

  17. 17

    Begg C, Cho M, Eastwood S, Horton R, Moher D, Olkin I et alImproving the quality of reporting of randomized controlled trials. The CONSORT statementJAMA 1996; 276: 637–639.

  18. 18

    Altman DG . Endorsement of the CONSORT statement by high impact medical journals: survey of instructions for authors. BMJ 2005; 330: 1056–1057.

    Article  Google Scholar 

  19. 19

    Jo JK, Autorino R, Chung JH, Kim KS, Lee JW, Baek EJ et al. Randomized controlled trials in endourology: a quality assessment. J Endourol 2013; 27: 1055–1060.

    Article  Google Scholar 

  20. 20

    Lee JW, Chung JH, Jo JK, Lee SW . Analysis of randomized controlled trials in Rheumatology International from 1981 to 2012: methodological assessment. Rheumatol Int 2014; 34: 1187–1193.

    Article  Google Scholar 

  21. 21

    Bridoux V, Moutel G, Roman H, Kianifard B, Michot F, Herve C et al. Methodological and ethical quality of randomized controlled clinical trials in gastrointestinal surgery. J Gastrointest Surg 2012; 16: 1758–1767.

    Article  Google Scholar 

  22. 22

    Lee JW, Chung JH, Jo JK, Lee SW . Assessing the quality of randomized controlled trials published in neurourology and urodynamics from 1993 to 2012. Neurourol Urodyn 2014; 33: 472–474.

    Article  Google Scholar 

  23. 23

    Kim SW, Choi YS, Ahn HS, Lee HY, Ahn DS, Lee YM . Quantity and quality assessment of randomized controlled trials published in five Korean medical journals, from 1980 to 2000. J Korean Acad Family Med 2004; 25: 118–125.

    Google Scholar 

  24. 24

    Clifford TJ, Barrowman NJ, Moher D . Funding source, trial outcome and reporting quality: are they related? Results of a pilot study. BMC. Health Serv Res 2002; 2: 18.

    Article  Google Scholar 

  25. 25

    Lee JY, Chung JH, Kang DH, Lee JW, Moon HS, Yoo TK et al. Quality assessment of randomized controlled trials published in the korean journal of urology over the past 20 years. Korean J Urol 2011; 52: 642–646.

    Article  Google Scholar 

  26. 26

    Schulz KF, Grimes DA . Allocation concealment in randomised trials: defending against deciphering. Lancet 2002; 359: 614–618.

    Article  Google Scholar 

  27. 27

    Hewitt C, Hahn S, Torgerson DJ, Watson J, Bland JM . Adequacy and reporting of allocation concealment: review of recent trials published in four general medical journals. BMJ 2005; 330: 1057–1058.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to S W Lee.

Ethics declarations

Competing interests

The authors declare no conflict of interest.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kim, K., Jo, J., Chung, J. et al. Quality analysis of randomized controlled trials in the International Journal of Impotence Research: quality assessment and relevant clinical impact. Int J Impot Res 29, 65–69 (2017).

Download citation

Further reading


Quick links