Rationale: predictive model, based on dependence of time till psoriatic arthritis onset on age of a patient at psoriasis skin manifestation, was previously developed and validated. This predictive model allows to get personal prognosis of time till psoriatic arthritis onset for patients with moderate or severe psoriasis. The following actual step in developing of prediction method is exploring the effect on the prognosis of other possible predictors. Aim: to assess the feasibility of patients with psoriasis separation by sex for predicting the time till psoriatic onset. Materials and methods: analysis of data of psoriasis patient registry of the Russian Society of Dermatovenereologists and Cosmetologists was performed. The number of patients with arthropathic psoriasis included was 1158, of whom 663 patients were males and 495 patients were females. Comparison of male and female patients datasets was performed. The median was used as a measure of central tendency, and the interquartile range (IQR) was used as a measure of dispersion. Pseudosamples were generated by bootstrap method. The differences in medians and IQR differences were calculated, and 95% confidence intervals (95% CI) were calculated. If the zero value of the difference in medians and the difference in IQR was within 95% CI, then at a significance level of 0.05, the hypothesis of homogeneity of the subsamples was accepted. Results: the zero values of the difference in medians and the difference in IQR in all ranges of the age of psoriasis onset are within 95% CI. This gives grounds to accept the hypothesis of homogeneity and to conclude about the absence of an effect of sex on the prognosis of time till joint damage onset. The estimates of prognosis obtained on datasets of male and female patients with psoriasis do not have significant differences. Conclusion: The patient's sex does not have a statistically significant effect on the time till psoriatic arthritis onset. When predicting the time till psoriatic arthritis onset depending on the age of patient at psoriasis onset, use of pooled data of male and female patients with psoriasis is feasible.