Sharifzadeh 2016.
| Methods | Randomised double‐blind placebo‐controlled trial Duration of study: from March 2015 to November 2015 |
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| Participants | Country: Iran Population: Idiopathic subfertile men, N = 114 Mean age: Inclusion criteria: Idiopathic subfertile male with sperm rates 5 ‐ 20 million cells/mL, and according to failure of female to conceive after one year regular and unprotected intercourse Exclusion criteria: chromatically fertility disorder (Y chromosome deletions), use of zinc three months before recruitment |
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| Interventions | Zinc sulphate 10 mL solution of 0.5% (n = 61) versus Placebo 10 ml (n = 53) Duration of treatment: 3 months |
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| Outcomes | Sperm parameters, side‐effects, serum and semen plasma levels of zinc | |
| Notes | Trial registration: IR.IUMS.REC.1394.26155 Email sent to second author Norouzi (sr.norouzi@yahoo.com) on 06.03.2018 to ask if they can provide mean+SD instead of median, and if the motility is total motility or progressive motility. Reply on 11.03.2018: "yes we use SD for motility and total concentration, for both of them instead of a median. Motility means group A+ B (progressive motility)" New email on 12.03.2018 to ask if they can then provide mean + SD. Reply on 04.04.18 answering "In this study we used the SPSS software (SPSS, Inc., Chicago, IL, USA, version 20) for statistical analyses. After normality testing confirmed by Shapiro‐wilk test, quantitative data were reported as mean ± SD. Unfortunately there are some spelling and statistical errors in the final version of article. In the review process, some changes have been made in the manuscript and subtitle of the tables have been deleted. So all outcome are Mean ± SD." |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "In the current study males were divided into groups A and B by block randomized sampling." Quote: "sub fertile males were assigned according to a simple computer schedule into two groups to receive zinc sulfate or placebo." |
| Allocation concealment (selection bias) | Low risk | Quote: "Solutions were coded from 1 to 120 according to the randomization list by hospital pharmacy. Each code was given to one participant to receive one container of solution that according to their group called participates took zinc sulfate (0.5) or placebo." |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: "Double‐blind" Quote: "Containers of zinc solution and placebo were similar, and all of them had zinc syrup label. The secretary of infertility unit did not know about the box content and patients by showing their groups label could receive the medicine." |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Not mentioned |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Quote: "seven subjects in the zinc group withdrew because of adverse gastrointestinal side effects, and three subjects in the zinc group and four subjects in the placebo group withdrew because of lack of motivation" Dropouts accounted for and reasons mentioned. No ITT |
| Selective reporting (reporting bias) | Low risk | Reported all the outcomes from the methods section and according to the protocol: trial registration (IR.IUMS.REC.1394.26155) |