Regarding the sex disparities between men and women, we found that female patients were significantly older at the time of stroke than men in the first group, although this was not the case with the second group. The age difference in the first period is consistent with previous findings that reported women were significantly older at the time of stroke [7,31−34]. While no significant difference was observed in the severity of stroke between men and women during the first period, the pattern of presentation has changed in the second group, with a higher proportion of women presenting with moderate and moderate-to-severe stroke compared to men. This finding aligns with previous claims that women had a higher stroke severity at admission [4, 7, 34]. There were no sex differences considering the mode of arrival and in-hospital mortality between men and women during the whole study period. Remarkably, we found that although DTN was previously affected by gender using the conventional algorithm (females had almost 4 times odds for delayed DTN as males, which increased almost to 6.5 times after adjusting for age, NIHSS at admission, mode of arrival, and time of admission), after employing the modified algorithm, being female was no longer associated with DTN> 1h, even after adjusting for important covariates. This interesting finding implies that using the modified algorithm with a special focus on D4 and D6 is plausible to alleviate sex disparities in DTN time, thereby improving females’ stroke outcomes. This result is consistent with findings from GWTG-Stroke (Get with The Guidelines-Stroke) study that showed adhering to a stroke performance program could narrow the gap in performance measures between men and women [4].
There is a discrepancy between study findings on gender disparities in DTN duration. The FL-PR CReSD Study (Florida-Puerto Rico Collaboration to Reduce Stroke Disparities) suggested after adjusting for multiple covariates, including the ones that we accounted for, being female is an independent predictor for having DTN≤ 1 hour (OR: 0.81, CI: 0.72-0.92) [3]. Similarly, large registry-based longitudinal studies from GWTG-Stroke also found that women had significantly less odds for having DTN within 1 hour (OR:0.83) [4]. A study among Dutch patients also revealed a significant relationship between female gender and having severely extended DTN (OR 1.17, 95% CI 1.05–1.31) [23]. In contrast, according to European studies, the average DTN for men and women are almost identical or differ only for a few minutes (2013; DTN in women: 67 [48-92] versus 66 [47-90] in men (P-value: 0.002), 2014; DTN: 49 [34-70] in women versus 48 [35-68] in men) [5, 18].
Generally, delayed diagnosis and the inability to determine eligibility are some of the most important reasons for DTN delay [19]. Various reasons are suggested for longer DTN in women, although these reasons are not clear yet [20]. Some of these factors are related to physicians’ decisions on patients’ eligibility and some others are patient-related factors. Regarding the former factors, studies suggested that physicians may be more reluctant to use r-tPA in women because they tend to be older or present with more severe stroke than men [33–35]. Additionally, several studies have revealed an increased prevalence in stroke mimics as well as non-traditional stroke manifestations in women which could affect physicians’ decisions considering the patients' eligibility for receiving r-tPA [7,36−38]. Moreover, previous studies suggested women are less likely to receive timely neuroimaging which could lead to longer DTN [35, 39], although some other studies found no disparity in this regard [32]. Considering the patient-related factors, some researches showed that women are less likely to consent to thrombolysis [4, 40]. Another possible rationale is that women are more likely to be widowed or living alone, resulting in delayed symptoms recognition, later hospital arrival, difficulty in obtaining the time of symptom onset from a family member, and ultimately eventuating in difficulty with physicians’ decision on the patient’s eligibility to receive r-tPA [17, 33].
Limitations and Strengths
This study was conducted at a single certified comprehensive stroke center, limiting its generalizability especially to the population who does not have access to specialized stroke care. However, our results were in line with large multicenter studies. We attempted to consider every possible factor that could affect the association between gender and DTN, though there might be some residual undetected confounding factors. We will gather more data in the following years and make every effort to treat both men and women as fast as possible.