Methods
Protocol and registration: The study protocol was
established and recorded in the International Prospective Register of
Systematic Reviews (Prospero: CRD42020198387).
Eligibility criteria: Studies investigating the
proportion of human subjects with accompanying thyroid disorders among
PE or DE sufferers or vice versa, correlation studies evaluating serum
TSH with IELT and/or PRO measures of the EjD sufferers and measuring
treatment effects that aim to establish a euthyroid state on the IELT
and/or PRO measures of thyroid dysfunction sufferers were considered for
this review. Both studies performed in the population and hospital
settings were eligible in the case of appropriate ethical review board
approval.
Information sources and search: An electronic data
search was performed on Medline (via PubMed) without any time limit. A
query by the different combinations of the following keywords:
“ejaculation” and “thyroid,” “serum TSH,” “serum T3,” and
“serum T4”was performed on July 3rd 2020 and updated on November 3rd
2020.
Study selection: Initial screening via review keywords
on PubMed was performed by the first author and title and abstract of
the journal articles were evaluated for eligibility. Randomized and
non-randomized studies on human subjects that declare ethical approval
and clearly report all of the components of the population,
interventions, comparators, and outcome measures of the trial were
eligible for our review. Reviews and meta-analyses of existing data were
not included in the current study. Irrelevant reports were removed, and
candidate studies for the scope of the current review were finally
evaluated for eligibility with their full-text files. Finally, the
relevance of the studies was assessed with both review authors not
blinded to the names and institutions of the study authors. The study
flow diagram is shown in Figure 1 and characteristics of the included
studies are shown in Table 1.
Risk of bias in individual studies: We established the
risk of bias assessment tool for eligible studies specific to the
current review and classified all of the included studies according to
their grade and type of bias according to GRADE recommendations for
evaluation of certainty of the evidence (Table 2) (Guyatt et al., 2008).
Summary measures: We rendered the presence of EjD,
either PE or DE, as a dichotomous qualitative outcome measure. The mean
PRO measures of the subjects and the mean of the IELT measurements in
the reviewed studies were quantitative outcome measures.