Table 1. Summaries of the articles used in this review per PRISMA Guidelines [5].

CT: computed tomography; US: ultrasound; LA: laparsocopic appendectomy; PA: perforated appendicitis; NPA: non-perforated appendicitis; LOS: length of stay; WBC: white blood cells; CRP: C-reactive protein; AAp/AA: acute appendicitis; NA: negative appendicitis; MD: missed diagnosis; SED: single encounter diagnosis; NFHCT: non-focused helical CT; RLQ: right lower quadrant

	Author	Country	Design and study population	Findings	Conclusion
1	Abdelhalim et al., 2015 [6]	United Kingdom	Retrospective Cohort Study (n = 363)	There was a significantly higher prevalence of males at 62% compared to females at 38%. 53% of female patients received pre-diagnostic imaging compared to 28% of male patients. There was a difference in the sexes in that CT scans were utilized by 72% of males compared to 40% of females, of whom the US was the favored imaging modality. Finally, there was a difference between the sexes in that LA was favored in females and attempted first in 72% of females compared to males accounting for 31%.	There was a difference between the chosen imaging modality between sexes in that males received more CT scans than females, and females underwent US more than males.
2	Akbulut et al., 2021 [7]	Turkey	Retrospective Cohort Study (n = 1,316)	The study identified male sex, WBC ≥ 10,900, and CRP ≥ 0.725 as independent risk factors for developing acute appendicitis. The most prevalent age group was localized to the second and third decade of life for developing AAp. However, developing perforation was localized to the fifth decade.	Male sex is a risk factor for developing acute appendicitis, although sex was not a contributing risk factor for perforation.
3	Augustin et al., 2011 [8]	USA	Retrospective Cohort Study (n = 380)	Males have an increased prevalence of perforated appendicitis than females. There was also evidence suggesting that males have an increased risk of perforation in the first 36 hours of diagnosis compared to females. Males were found to have a shorter duration of perforating their appendix when compared to females.	There was a suggested finding that there is a risk of early perforation with a diagnosis of acute appendicitis. In this finding, it was expressed that males above 55 are at highest risk for early perforation.
4	Avci and Ayengin, 2019 [9]	Turkey	Retrospective Cohort Study (n = 267)	The incidence of acute appendicitis was higher in males, accounting for 63%. However, the number of perforated appendices was higher in females at 59% when compared to males and associated with a longer LOS.	The rate of perforated appendix was significantly higher in females than males, despite males having a significantly higher incidence of appendicitis
5	Bachur et al., 2012 [10]	USA	Retrospective Cohort Study (n = 55,227)	In male children, the rate of NA was 16.8%, significantly higher than in females, which was 14.6% for patients below the age of 5. However, after the age of 5, females were significantly more likely to have NA	This study suggests that there is a difference in negative appendectomy rate based on imaging modality when comparing both age and sex.
6	Barışık et al., 2020 [11]	Turkey	Prospective Cohort Study (n = 643)	There is a statistical significance between the age of appendicitis diagnosis in males and females, as well as BMI, cigarette smoking, sheesha smoking, family history of diabetes, and hypertension. There was also statistical significance in the perception of pain of acute appendicitis between males and females.	CT was more cost-effective than the US when diagnosing appendicitis. This study also identified potential factors as being high risk, some of which are nausea, vomiting, guarding, and loss of appetite.
7	Gil et al., 2023 [12]	USA	Prospective Cohort Study (n = 51,164)	A significantly lower proportion of those diagnosed with appendicitis were females. 98.2% of the population had SED, and 1.8% had MD, the strongest predictor of appendiceal perforation. MD’s were more likely to occur in females.	Minority race and females at high risk of MD and appendiceal perforation. The high rate of MD correlates to errors in clinical judgment and the decision not to pursue additional differential tests.
8	Günay et al., 2022 [13]	Turkey	Case-Control Study (n = 186)	Marked increases in Rho-kinase 1 and mRNA expression were observed in male patients. No significant variation was observed in alleles and genotype frequencies for Rho-kinase 1 genes rs35996865 and Rhino-kinase genes rs2230774 polymorphisms in AA patients and the control group.	Rho-kinase 1 and Rho-kinase 2 genes were no significant AA development risk factors. However, increased expression of mRNA of the Rho-kinase 1 genes in males suggested that this gene predicts the pathogenesis of AA in a sex-specific manner.
9	Kambouri et al., 2019 [14]	Greece	Retrospective Cohort Study (n = 602)	AA diagnosis for males was delayed for at least 48 hours in 47.7%. Males diagnosed but did not take antibiotics had lower odds of a prolonged diagnostic period greater than 48 hours. Females who took antibiotics are 12 times more likely than those who do not take antibiotics to have a longer diagnostic period greater than 48 hours.	Physicians assessing children with abdominal pain should consider various causes of diagnostic delay that can contribute to serious complications and prolonged hospital stays.
10	Lin et al., 2015 [15]	Taiwan	Population-Based Study (n = 294,544)	The incidence of appendicitis was 107.76 per 100,000 person-year, with the highest incidence between 15-29 years of age. Males had a significantly higher rate than females, except those over 70. Males with appendicitis were more likely to have a perforated appendix.	Males had a higher incidence of appendicitis and were more likely to develop perforated appendicitis compared to females.
11	Salö et al., 2015 [16]	Sweden	Retrospective Cohort Study (n = 427)	The rates of phlegmonous appendicitis, perforated appendicitis, open appendectomy, and RLQ tenderness with percussion/coughing/hopping were higher in males. In females, negative appendectomy, operative complications, gangrenous appendicitis, and pre-operative imaging were found to be higher.	Sex differences were noted, with males having appendicitis with perforation more than females and females had higher rates of negative appendectomies and operative complications.
12	Seow et al., 2022 [17]	Singapore	Retrospective Cohort Study (n = 1,185)	Males represented 79.3% of the sample, significantly more than females. The average duration of symptoms was 1.8 days with a mean LOS of 3.6 days, with males being a risk factor for prolonged LOS	Males were significantly more likely to develop appendicitis and were a risk factor for a prolonged LOS
13	Weiss et al., 2023 [18]	Israel	Retrospective Cohort Study (n = 1,839)	Males were found to have a significantly lower chance of receiving analgesia; however, males were associated with a significantly higher chance of receiving a minimum of one opioid medication, assuming that they were started on pain medication.	Males were not as likely as females to receive analgesics for pain management, but when given analgesics, males were more likely to receive at least one opioid.
14	Zvizdic et al., 2021 [19]	Bosnia	Retrospective Cohort Study (n = 295)	31.2% of patients had a perforated appendix. The male sex, fever, diarrhea, vomiting, high CRP levels, and elevated WBC levels were found to be predictors of perforated appendicitis.	Predicting factors to help distinguish between perforated and non-perforated appendicitis are the male sex, fever, CRP levels, and elevated WBC levels.
15	Ahmed et al., 2020 [20]	Iraq	Prospective Case Series Study (n = 5,847)	This study found that the most likely age group for acute appendicitis was between the age ranges of 21-40; within this age range, the female-to-male ratio was 1.49:1.00, respectively. This study found that the most likely age group for suspected appendicitis was the age range of 31-40, which had a female-to-male ratio of 1.5:1.00 respectively. The most common cause of morbidity in both sexes was surgical site infection.	Female patients have more postoperative complications than males when receiving appendectomy. However, no statistically significant findings suggest an increase between sexes in the development of appendicitis.
16	Şenocak et al., 2020 [21]	Turkey	Retrospective Cross-Sectional Study (n = 202)	For both sexes, the Ohmann scoring system was found to identify acute appendicitis the best, resulting in the lowest negative appendectomy rates (3.4% in males and 6.9% in females). Although combining the scores with ultrasonography did not increase the accuracy of diagnosing acute appendicitis, combining the Ohmann scoring system with ultrasonography resulted in a decrease of negative appendectomy rates for females from 6.9% to 4%.	The Ohmann score provided the best negative appendectomy rate and is a good diagnostic predictor of acute appendicitis in both male and female patients. When combined with ultrasonography, it resulted in a further decrease in the female negative appendectomy rate while minimally reducing the rate for females.
17	Drake et al., 2014 [22]	USA	Prospective Cohort Study (n = 9,048)	There was a significantly higher amount of males (55.3%) who developed a perforated appendix compared to females (52.1%), and males were also found to be an independent risk factor for developing PA. Males also had a shorter time to treatment following diagnosis compared to females.	Perforation was correlated with the male sex, who also had a significantly shorter time frame from diagnosis to treatment.
18	McGann Donlan and Mycyk 2009 [23]	USA	Retrospective Cohort Study (n = 137)	The time from triage to CT order was 95 minutes in males and 138 minutes in females. The time from initial physician evaluation to CT order was 28 minutes in males and 45 minutes in females. Nonclassic symptoms were prevalent in females, and pelvic evaluation did not delay the CT order.	Female sex is associated with delays in CT acquisition and diagnosis of appendicitis.
19	Stein et al., 2012 [24]	Israel	Retrospective Cohort Study (n = 3,736)	Males were found to have more appendicitis attacks, while females were found to have a greater number of normal appendixes. The summer season months had increased numbers of appendectomies for acute appendicitis. There was a 0.33% mortality rate, with the majority being elderly and female, as the male:female ratio was 0.4.	Acute appendicitis was found to be more frequent in the summer season and the male sex. Females also had a slightly higher mortality rate than males.
20	Dohner et al., 2023 [25]	Switzerland	Retrospective Cohort Study (n = 457)	There were slightly more males diagnosed with appendicitis during this time frame compared to females, but neurogenic appendicopathy was diagnosed more frequently in females. Female sex was associated with more frequent in these patients than in those with acute appendicitis.	While males were more likely to be diagnosed with appendicitis, females were more likely to be diagnosed with acute and neurogenic appendicopathy.
21	Lien et al., 2011 [26]	Taiwan	Prospective Cohort Study (n = 128)	There was no significant difference in NPA and PA groups with recurrence rate; however, male sex was associated significantly with recurrence.	There was a significant risk of recurrence of appendicitis in males.
22	Oguntola et al., 2010 [27]	Nigeria	Retrospective Cohort Study (n = 299)	52% of patients in this study were males. Admission rates of appendicitis in both sexes have increased since 2004. The incidence of appendicitis in both sexes was significantly higher during the rainy season.	There is an increase in the incidence of appendicitis in males, but the overall incidence in both sexes has been increasing since 2004.
23	Sulu et al., 2010 [28]	Turkey	Retrospective Cohort Study (n = 1,871)	Appendicitis was seen mostly in males between the ages of 10 and 19, while perforate appendicitis was seen the most in the 0-9 and 50+ years age groups. Appendicitis was seen mostly in the winter months, while perforation rates were the lowest.	Appendicitis frequency was affected by age, sex, and possibly by seasons and temperatures.
24	Livingston et al., 2007 [29]	USA	Retrospective Cohort Study	Between 1970 and 1995, there was a decrease in the negative appendectomy rate in females. Nonperforated rates have been oscillatory, with large peaks in the male population. The rate of perforated appendicitis and abscesses has decreased in both sexes.	There’s been a decline in non-perforated appendicitis and an increase in appendectomies associated with the implementation of new technology
25	Peeters et al., 2023 [30]	Belgium	Retrospective Cohort Study (n = 9,723)	Male sex was found to be a significant independent risk factor in developing appendicitis.	Males are at an increased risk of developing appendicitis
26	Raman et al., 2003 [31]	USA	Retrospective Cohort Study (n = 552)	The sensitivity of NFHCT to diagnose appendicitis was significantly higher in males, while specificity was slightly higher in females. Accuracy of the diagnosis, however, did not differ between sexes. Males were slightly more likely to have thickened appendix and periappendiceal stranding.	NFHCT may be highly accurate in diagnosing appendicitis.
27	Peixoto et al., 2011 [32]	Brazil	Prospective Cohort Study (n = 156)	Sex differences did not alter the diagnostic accuracy of abdominal ultrasonography to diagnose appendicitis.	Sex does not influence the accuracy of ultrasound to diagnose appendicitis.
28	Akbulut et al., 2019 [33]	Turkey	Retrospective Cohort Study (n = 360)	No statistically significant data was identified that suggested a link between the sexes of patients and their likelihood of receiving a diagnosis of acute appendicitis. There were also no differences between the sexes regarding the incidence of incidental and emergent appendectomies.	The study did not find any significant link/difference with regards to sex linking patients who received incidental appendectomy and those who received emergent appendectomy.