BACKGROUND: There has been unexpected influx of patients into hospitals, especially in United Kingdom. The reasons for non-elective hospital admission in hospital (NeHA) remain poorly understood. The unprecedented rise in NeHA places severe financial and manpower strain on hospitals, due to the continuous targets to meet statutory patients’ expectations and admissions demand OBJECTIVE: This research study examines the sociodemographic risk factors that account for non-elective hospital admission among patients who experienced non-elective hospital admission(s). METHOD: A review of literature was carried out to identify relevant studies published between 2010 and 2017 using a range of search engine including CINAHL, Medline, Scopus and Cochrane Library. Inclusion criteria were; published in the English language, cohort studies, with population sample aged mostly 18 years and above, not a specific health condition and focused on influencing factors for NeHA(s). FINDINGS: From a total of 6,889 reviewed papers, 15 studies on risk factors to NeHA(s) met the inclusion criteria. Data extraction sheets captured information on the population setting, study design, characteristics, quality assessment, methodology, findings and risk factors included in the analysis. Less studies addressed non-clinical risk factors. Seven studies relied on retrospective administrative data which explored unplanned hospital admission. From the overall studies, only 1 study in Belgium reported a discriminative ability (c statistic: 0.73). Another UK study yielded a R-squared value of 0.74, while the remaining studies presented result using odds ratio at a 95% confidence interval (ranging from 0.001 to 8.600). Six studies explored similar models within the same population, from which various non-clinical risk factors, including deprivation, age, sex, ethnicity, financial support, income, living situation and social factors, were reported as risk factors for unplanned hospital admission(s). Thirteen out of the fifteen included studies incorporated variables for groups of conditions, which capture physical illness, cognitive heart failure and mental health conditions. Two studies did not report variables relating to patient’s health condition rather they presented demographic characteristics. Age was found to be a significant influencing risk factor to non-elective admissions in 8 out of the 15 studies that were included and was the most dominant significant risk factors among the sociodemographic risk factors that were examined. Sex was also reported to be significant in 4 studies, while ethnicity was reported to be significant in only 3 studies which and were conducted in the UK among a reasonable population sizes ranging from 867 to 1,177,304. CONCLUSION: The findings suggest that, recent studies on non-elective hospital admission(s) were designed for clinical comparative purposes and very few studies reflected the implication of non-clinical sociodemographic risk factors as presented in this review. The outcome of this review presented age, sex and ethnicity as the sociodemographic risk factors influencing NeHA, a discovery that emerged from the three levels classificatory system, which was uniquely produced in this review. Thus, health organisations should therefore, render necessary intervention towards older ethnic minority men, that are rated high unplanned hospital utilizers, so that the exceptional increase in NeHA could be significantly reduced.