With the dual challenge of shrinking finances and growing population needs, the health sector finds itself under pressure. Reducing ALOS is an effective way of containing this growing demand for beds as well as releasing capacity in the health system. However, there is often significant variation in ALOS between and within hospitals, suggesting the need for improvements in internal processes, tracking systems, and the development of alternative services [7].

HAI also imposes costs on both patients and society in the form of increased resources, loss of time and effort, in addition to psychological and emotional suffering. Relation between LOS and HAI is interrelated. In many cases, the onset of HAI extends ALOS, and in other cases, the increased ALOS may increase the probability of HAI [8].

Since the COVID-19 pandemic in 2020, continuous risk assessment and management strategies have been generated and applied for early diagnosis, containing and controlling infection [9, 10].

The risk of COVID-19 infection is associated with epidemiological factors, host status, immunity, age, overall health, etc. [11, 12]. It is critical to protect susceptible populations by eliminating the transmission risks and benefit from hazard control practices [13] so patients having cancer and undergoing surgery were targeted in this study as a high-risk group that requires special care for prevention and control of such infection.

Out of all included patients from January to June, only 2.2% of patients were positive for COVID-19 infection. This was lower than a similar study on cancer patients documented a 7.8% infection rate [14].

The whole ALOS was 10 days in the current study. This was similar to what is documented by the previous study [15] with ALOS of 10.3 days and comparable to what is in another study [16], with 9.1 days.

In this study, ALOS reached a maximum of 42 days in some patients. This number lies in the previously described range by a systematic review of 52 published articles, with a maximum ALOS varied from less than a week to nearly 2 months [17].

In the current study, there was a statistically significant difference in preoperative ALOS across the 6 months (p value < 0.001) with significantly lower ALOS in the later months (April, May, and June) than in the former months (January–February, and March) which is linked to the continuous and effective risk management and monitoring during this period.

Despite the less common use of preoperative ALOS as an indicator of efficient risk management than the postoperative and whole ALOS, it is considered a better indicator in this study. This is due to the presence of many confounding factors that may interact and prolog the whole ALOS (e.g., different stages of disease requiring different treatment strategies, presence of medical or nonmedical conditions leading to postponed surgery), as well as the post-operative ALOS (e.g., postoperative complications, in compliance to treatment or medical instructions).

No significant difference was found among the 6 surgical departments (p value = 0.423) which could be explained by the consistent application of risk management measures across all departments.

Regarding COVID-19 infection, only 28 out of the 1287 patients became positive after admission. As expected, a small number of COVID-19 patients (n = 3) were infected during (January and February, the inter-wave duration) and 25 were infected (from March to June, the 3rd wave duration).

Combined analysis of COVID-19 infection rates across the 6 months pooling the inter-wave duration together with the duration of the 3rd wave might have masked a significant change in COVID-19 infection across the 6 months, so a separate analysis of the 3rd wave duration (from March to June) was done and it revealed a statistically significant decreasing trend of infection (p value = 0.009). This decreasing trend was opposite to the rising curve of infection by that time. A finding can be explained by the decreasing admission rates during the same duration as well as endorsing the efficiency of risk management and infection control measures as well as the lowered ALOS during this period.

Failure of spotting a significant link between COVID-19 infection rate and ALOS duration is explained by the small number of infected cases that could have hindered observing a possible significant relation.

Average duration between negative and positive swabs was 6 days with a lower number of positive COVID-19 patients when re-swabbing was done within 5 days than when done after 5 days, so shortening of the re-swabbing period could lower the chance of COVID infection through early identification and isolation of positive patients.