Document retrieval

In total, 1716 articles were obtained from the initial search. Of these, 1018 articles were obtained after the first screening, and 77 RCTs were finally included after the second screening. The specific literature retrieval process and results are presented in Fig. 1.

Fig. 1

Flow chart of literature screening for RCTs of CP/CPPS. The number of final analysis RCTs of CP/CPPS, included and excluded articles, from the PubMed, Web of Science, and Embase databases

Basic characteristics of the included studies

The sample of these studies ranged from 17 to 324, with a median of 64, and only 12 (15.58%) of the studies described the process and method of sample size estimation. 21 (27.27%) were multicenter studies, with 2 to 34 research centers. The baseline information was consistent and comparable across studies. The RCTs all aimed to evaluate the effectiveness and safety of the interventions. Regarding the diagnostic criteria for CP/CPPS, 8 (10.39%) studies used the Chronic Prostatitis Collaborative Research Network sponsored by the National Institutes of Health; 4 (5.19%) studies used the European Association of Urology guidelines; 53 (68.83%) studies stated that the diagnosis was made based on history, physical examination, and laboratory tests; and 12 (15.59%) studies only mentioned patients with CP/CPPS, without specifying which diagnostic criteria were used. Of the interventions, 9 (11.69%) studies were alpha1 receptor blockers, including terazosine, doxazosin, and alfuzosin. 5 (6.49%) studies were pollen extracts, and other therapeutic agents included finasteride, palmetto, tamsulosin, silodosin, apremilast, tanezumab, duloxetine, pregabalin, rofecoxib, and zafirlukast, among others. 8 (10.39%) of the studies were extracorporeal shock wave therapy, and other physical rehabilitation treatments included transurethral needle ablation, transurethral microwave thermotherapy with urethral cooling, sono-electro-magnetic therapy, transcutaneous electrical nerve stimulation, repetitive transcranial magnetic stimulation, posterior tibial nerve stimulation, myofascial physical therapy, and cryotherapy, etc. Among the control groups, 44 (57.14%) studies used a placebo or sham treatment, and 33 (42.86%) studies used positive treatment.

Literature quality evaluation results based on the CONSORT statement

The evaluation of the quality of the literature in the CONSORT statement included the title and abstract, introduction, methods, results, conclusions, and other information. The number and percentage of articles for each topic are presented in Table 1.

Table 1 Assessment of the quality of RCTs of CP/CPPS based on the CONSORT statementTitle and abstract

Among the included 77 RCTs, 67 (87.01%) articles mentioned “randomized” and “controlled” in the title and abstract, and the other 10 (12.99%) articles did not specify the type of study in the title and abstract.

Randomization, blinding, and allocation hiding

Although the 77 included RCTs mentioned “randomized,” only 26 (33.77%) papers mentioned the specific randomization methods. Among them, 17 (33.77%) papers generated random assignment sequences by computer, and 9 (11.69%) papers used the order of patient visits as the grouping method. Only 26 (33.77%) articles mentioned the “blind method,” but they did not explain how the method was implemented. 6 (7.79%) studies mentioned allocation hiding.

Subjects and test procedures

36 (46.75%) articles mentioned the recruitment of subjects and the baseline situation of subjects. Conversely, only 6 (7.79%) articles used graphs to present the baseline data. Only 34 articles (44.16%) recorded the number of patients who withdrew from each group after random grouping. 16 (20.78%) articles used flowcharts to record the test process.

Adverse reactions

Of the 77 included RCTs, 67 (87.01%) studies reported whether adverse events occurred during the study, and none of the remaining literature stated whether adverse events occurred before or after the trial.

Statistical methods

Among the 77 included RCTs, all articles specifically described the statistical methods used to compare the primary and secondary outcome indicators of each group, and 15 (19.48%) articles described the methods of additional analysis.

Clinical registration, plan announcement, and funding description

Among the included studies, only 16 (20.78%) documents stated that they were registered on various registration platforms, only 3 (3.90%) mentioned the relevant trial schemes and 6 (7.79%) mentioned funding status.

Interpretation of results

Among the 77 included RCTs, 57 (74.03%) studies described the limitations and reasons for the trial in the discussion section. And 57 (74.03%) studies provided explanations that are consistent with the experimental results. Meanwhile, 61 (79.22%) articles provided negative results.

Literature quality evaluation results based on the improved Jadad scale

Among all 77 articles evaluated by the improved Jadad scale, only 19 (24.68%) had a score of ≥ 4. Meanwhile, 58 (75.32%) were low-quality studies (score ≤ 3), and little of them mentioned random hiding and execution. The number and percentage of articles for each score are presented in Table 2.

Table 2 Assessment of the quality of RCTs in the treatment of CP/CPPS based on improved Jadad scale scores