In the hospitals surveyed, out of a total of 245 patients, 38.37% had unnecessary admissions, and 39.29% had unnecessary hospitalizations. In some studies, the rate of unnecessary admissions was higher than that of unnecessary hospitalizations. This finding is consistent with our results. Additionally, the rate of unnecessary admissions and its associated factors were completely different from those in the present study (
10,
14). There is no significant association between patient age and unnecessary admissions or unnecessary hospital stays. Similar studies have shown that age is not a significant factor in the rate of hospitalization and hospital stays (
18,
20-
23). Studies conducted around the world also show that age has no effect on unnecessary admissions and unnecessary hospital stays (
4,
6,
9). The findings of this study show that there is a significant relationship between gender and unnecessary hospital stays. In this study, the majority of hospitalized patients were women. The results of several studies indicate that women consume more health services than men (
17). In the National Health Service Utilization Study in the country, it was also found that women are more likely than men to seek health care services (
18). Similar studies also found that women accounted for the majority of hospitalizations (
19,
20). Regarding the relationship between inappropriate admission and gender, the results showed that inappropriate admission was significantly higher in women than in men. This can be analyzed by considering that, due to the physical and psychological differences in women compared to men, women have a greater sense of dependence, need, and attention to health. This increases the likelihood of inappropriate admission in women. To address this problem, the establishment and expansion of family physicians and referral systems can provide reassurance to this segment of society and reduce costs.
Insurance coverage is significantly associated with unnecessary hospital admissions. Most patients admitted to the hospital had insurance coverage, and patients without insurance coverage had a longer average stay than patients with insurance. It can be inferred that people without insurance coverage are likely to have more severe illnesses due to delays in seeking medical attention and therefore have longer hospital stays. In general, the source of payment is an important determinant of healthcare utilization. A study by Nabi Lu shows that insured people have higher rates of health service utilization compared to uninsured people (
26).
Before conducting the present study, it was hypothesized that high hospitalization coverage by the insurance organization (especially social security insurance with zero deductible) would increase demand and consequently increase unnecessary hospitalizations. This led to the hypothesis that "insurance coverage is associated with unnecessary hospitalizations", but the opposite was proven.
The type of ward and the type of treatment (non-surgical or surgical inpatient) were two variables that influenced unnecessary hospitalizations. Inappropriate admissions were significantly higher in patients who received non-surgical inpatient treatment. Regarding the variable of ward type, the emergency department had the highest number of inappropriate admissions. Concerning the days of inappropriate hospitalizations, the effect of the two variables of treatment type and ward type on the days of inappropriate hospitalizations was significant.
Regarding the factor of residence, it was also found that this factor is related to hospital stay. A higher percentage of hospitalized patients were city residents. The reasons for hospitalization are also significantly associated with unnecessary admissions and unnecessary hospitalizations. The results of various studies show that the severity and type of illness affect the length of a patient's stay in the hospital (
17-
25,
31).
The results of this study show that patients hospitalized due to gastrointestinal diseases have more unnecessary admissions and hospitalizations than other patients, which is attributed to the long duration of treatment for these diseases. In this study, there was a significant relationship between admission days on holidays and weekdays with unnecessary admissions and unnecessary hospitalizations. This finding is consistent with the results of several studies. In a national study, 37.3% of unnecessary hospitalizations occurred on Thursdays and Fridays, and 2.09% on other days of the week, indicating a significant relationship between unnecessary hospitalizations on holidays and weekdays (
24).
Companion status is another factor affecting unnecessary admission and unnecessary hospital stay, with the LOS for patients with companions being shorter than for those without companions. The negative effect of having a companion on the length of hospital stay is likely due to the fact that patients with companions require fewer days of hospital stay than unaccompanied patients, owing to family support and care in the home environment (
26,
27).
The findings of the present study show that one of the main reasons for inappropriate patient hospitalization is "delays for laboratory and radiology tests". Pourreza et al. also mention the follow-up of clinical test results as the fifth most important factor in inappropriate patient stays (
1). In fact, physicians believe that in more than 50% of cases, test results delay patient treatment and increase the LOS (
21).
Since 60 - 70% of the objective information in patient records is related to laboratory data, delays in reporting laboratory results will subsequently lead to delays in the diagnosis and treatment of patients (
34). According to previous studies, there is a significant relationship between laboratory services and laboratory turnaround time (
33-
35). Many studies have identified mechanisms such as workflow automation, electronic medical record systems, process redesign and reengineering, and point-of-care testing as tools to reduce test cycle times (
38-
43). Some studies show that redesigning the laboratory workstation and eliminating unnecessary staff turnover can increase laboratory throughput (
39,
40). Laboratory workstation redesign and the elimination of unnecessary staff turnover are other approaches that contribute to expediting access to laboratory results and reducing patient LOS. Studies show that turnaround time has been reduced by an average of 87% after implementing laboratory workstation redesign and eliminating unnecessary staff turnover (
38-
40). The use of process automation tools is suggested as another solution to reduce turnaround time.
The results of this study, in confirmation of other studies, showed that accelerating access to imaging and radiology results and reducing the turnaround time for radiology procedures are other effective factors in reducing the LOS of patients (
41). In this area, the use of image archiving and transfer systems and voice recognition technology are additional tools that can reduce the turnaround time for radiology reports and, consequently, the number of unnecessary days of patient stay (
42,
43).
The present study showed that hospital postponement of surgery is another factor affecting inappropriate patient stays. Any inappropriate use of the operating room can cause delays in providing care to the patient and, as a result, impose costs on healthcare institutions (
44-
46). Improving surgical and non-surgical turnaround time is a major consideration for healthcare institutions (
44-
49). In this context, improving inefficient surgical time through the use of technology, preoperative assessment of high-risk patients and identification of comorbidities, appropriate scheduling and planning of educational, research, and executive activities of surgeons to reduce surgical cancellations, and educating and informing them about the financial losses resulting from surgical cancellations, as well as redesigning, reviewing, and improving workflows, are effective measures to improve surgical turnaround times (
50-
53).
In this context, it is recommended that centers or units be designed in hospitals for appropriate preoperative visits and screening of high-risk patients. Additionally, some studies have found that most of the reasons for surgical cancellations were related to surgeons. Setting up a preoperative assessment clinic is one of the mechanisms for reducing surgical cancellations (
54,
55). The absence of the surgeon, lack of proper planning regarding the number and sequence of surgeries, prolonged previous surgery, change in the diagnosis of the disease, or transfer of the patient to another department are considered to be the main reasons for surgery cancellation in the hospital (
55). Therefore, it is recommended that the possibility of surgical cancellations be reduced as much as possible through appropriate scheduling and planning of educational, research, and executive activities of physicians, as well as training and awareness-raising for them. Here, it may be helpful to remember that the perceptions of healthcare recipients about the service determine their behavior, not its actual effects (
56-
59).
Finally, the review of studies and the results of this study showed that unnecessary hospital stays are a significant issue driven less by patient demographics like age and more by gender, access factors (insurance, residence), and critical inefficiencies within the hospital system itself. The primary causes are operational bottlenecks, particularly delays in diagnostic services and surgical scheduling. Therefore, the focus for reducing unnecessary hospitalizations should shift from patient characteristics to improving internal hospital processes. Implementing strategic interventions such as workflow automation, pre-operative patient assessment, and better resource planning is essential to enhance efficiency, reduce costs, and optimize the use of hospital beds.
5.1. Conclusions
The study reveals alarmingly high rates of unnecessary hospital admissions and inpatient days, primarily driven by systemic inefficiencies rather than patient demographics. To address this, practical interventions are essential: Implementing automated systems and process redesign to expedite laboratory and radiology results, establishing pre-operative assessment clinics to reduce surgery cancellations, and strengthening primary care networks like the family physician program to manage demand appropriately.
In addition, interventions based on health information technologies, such as the use of hospital information systems (with an increased focus on clinical data recording) integrated with medical image storage and exchange systems, remote consultation, electronic tools for discharge planning and management of specialized consultations, and smart management dashboards, also help reduce LOS by optimizing processes related to patient admission, hospitalization, transfer, and discharge. Collectively, these interventions can improve hospital efficiency, reduce unnecessary utilization, and enhance the overall quality of healthcare delivery.
5.2. Limitations
This study was conducted in two governmental non-teaching hospitals in Shiraz, which may limit the generalizability of the findings to other types of hospitals (e.g., teaching or private hospitals) or other regions of Iran. The retrospective design, which relied on the accuracy and completeness of medical records, is another limitation of this study.