Initially, 334 articles were found, and based on the criteria for the review of the titles and abstracts, avoidance of duplicates, and similarity of the contents, 12 articles were selected for the final analysis.
Figure 1 shows the flowchart of the database search and selection of the final articles.
Flow chart of systematic search and studies selection
Table 1 shows the average elasticity of the inputs of physicians, nurses, active beds, other staff, technology, and virtual variables in the selected studies. The elasticity in the logarithmic functions indicated that per one percent of change in the explanatory variable, the dependent variable changed by a few percent. For instance, the elasticity of physicians showed that if the number of physicians changed by 1%, to which extent the output change of the hospital would change. The physician input elasticity was estimated at 0.22, and the nurse input elasticity was estimated at 0.55. In other words, per every 1% increase in the physician input, a 22% increase would occur in hospitalizations. In addition, the number of hospitalized patients increased by 55% with the employment of more than one nurse. The active bed input elasticity was estimated at 0.64, and per every 1% increase in the bed input, patient admission would increase by 64%. The average elasticity of other staff, technology, and virtual variables were estimated at 0.36, 0.0004, and 0.047, respectively.
| Author | City | Physician | Nurse | Bed | Other Staff | Technology | Virtual Variable | Summed Elasticity | Return to Scale |
|---|
| Mahboobi Ardakan et al. (1) | Mashhad | 0.57 | 0.36 | 0.24 | -0.07 | 0.0004 | 0.047 | 1.1 | Increasing |
| Rezapoor et al. (6) | Qazvin | -0.55 | 0.29 | 0.81 | 0.73 | NA | NA | 1.28 | Increasing |
| Yaghoubi et al. (7) | Ahvaz | 0.28 | 0.1 | 0.95 | -0.11 | NA | NA | 0.88 | Decreasing |
| Karimi et al. (5) | Esfahan | 0.01 | 0.11 | 0.91 | 0.008 | NA | NA | 1.03 | Increasing |
| Hadian et al. (3) | Orumieh | 1.08 | 3.4 | 1.4 | 2.08 | NA | NA | 8.68 | Increasing |
| Rezaei et al. (8) | Kurdistan | 0.17 | 0.25 | 0.2 | 0.44 | NA | NA | 1.06 | Increasing |
| Kardan Moghadam et al. (9) | Yazd | 0.18 | -0.2 | 0.5 | NA | NA | NA | 0.48 | Decreasing |
| Karami Matin et al. (10) | Kermanshah | 0.115 | 0.18 | 1.02 | 0.14 | NA | NA | 1.45 | Increasing |
| Mehraban et al. (11) | Social Security Organization Hospitals | 0.073 | 0.0 | 0.835 | 0.0201 | NA | NA | NA | NA |
| Sabbagh Kermani & Shaghaghi Shahri (2) | Iran | 0.18 | 1.72 | 0.17 | 0.12 | NA | NA | 1.83 | Increasing |
| Pourmohammadi et al. (12) | Social Security Organization Hospitals | 0.05 | 0.04 | 0.52 | 0.04 | NA | NA | 0.65 | Decreasing |
| Haqparast (13) | General Hospitals of Iran University of Medical Sciences | 0.52 | 0.33 | 0.22 | -0.07 | 0.0004 | NA | 1 | Constant |
| Average | | 0.22 | 0.55 | 0.64 | 0.36 | 0.0004 | 0.047 | 1.76 | Increasing |
Abbreviations: NA, not available
Table 2 shows the reported marginal production and average production of the production inputs in the hospitals in Iran in the reviewed studies. Average production is defined as the average output of each unit of labor per unit of time. According to the findings, the average number of the hospitalized patients per each physician was 219.63, and the average number of the hospitalized patients per each nurse was 50.38. In addition, the average production of the active bed inputs and other staff was estimated at 43.06 and 37.76, respectively.
| City | AP Physician | AP Nurse | AP Bed | AP Other Staff | MP Physician | MP Nurse | MP Bed | MP Other Staff |
|---|
| Mashhad (1) | 2.42 | 1.61 | 1.22 | 0.99 | 1.24 | 0.53 | 0.25 | 1.24 |
| Qazvin (6) | NA | NA | NA | NA | -114 | 38.6 | 54 | 37 |
| Ahvaz (7) | 386.28 | 66.62 | 49.28 | 91.57 | 109.15 | 6.72 | 46.63 | -9.69 |
| Esfahan (5) | 3.36 | 1.86 | 1.78 | 1.72 | 0.03 | 0.2 | 1.62 | 0.01 |
| Orumieh (3) | NA | NA | NA | NA | 391 | 244 | 103 | 273 |
| Kurdistan (8) | 317 | 93 | 81 | 71 | 56 | 23.6 | 16.7 | 40.9 |
| Yazd (9) | NA | NA | NA | NA | 44 | 19 | 27 | NA |
| Kermanshah (10) | 555 | 91 | 77 | 44 | 73.3 | 19.3 | 76.7 | 6.7 |
| Social Security Organization (11) Hospitals | NA | NA | NA | NA | 9.48 | 1.73 | 79.14 | NA |
| Iran (2) | NA | NA | NA | NA | NA | NA | NA | NA |
| Social Security Organization Hospitals (12) | 271 | 97 | 90 | 54 | 14 | 4 | 47 | -2 |
| General Hospitals of Iran University of Medical Sciences (13) | 2.39 | 1.60 | 1.20 | 1.09 | 1.24 | 0.52 | 0.26 | -0.07 |
| Average | 219.63 | 50.38 | 43.06 | 37.76 | 53.22 | 32.56 | 41.10 | 38.56 |
According to the obtained results, the highest rate of average production belonged to the physician input (219.63), and the lowest rate belonged to the other staff input (37.76).
Table 2 also shows the marginal production of the factors of hospital production for all the inputs. Marginal production is defined as the ration of change in total production per unit of additional labor per unit of time. For instance, the marginal production of physicians was the ration of change in the total hospital production per unit of additional physicians per unit of time.
According to the findings, the marginal production of the physician input was 53.22 as with the employment of one more physician unit, the total number of the inpatients (total hospital production) increased by 53.22 units. The marginal production of nurses was 32.56 as with the employment of one more nurse, hospitalization (total productivity) increased by 32.56 units. Furthermore, the marginal production of the active bed and other staff inputs was 41.10 and 38.56, respectively, and the highest rate of marginal production belonged to physicians (53.22).
In the reviewed studies, the marginal rate of technical substitution (MRTS) of the inputs was also reported in Mashhad (
1), Qazvin (
6), Ahwaz (
7), Iran (
2), social security organization hospitals (
12), and the general hospitals affiliated to Iran University of Medical Sciences (
13), as well as in Isfahan (
5), Urmia (
3), Kurdistan (
8), Yazd (
9), Kermanshah (
10), and social security hospitals (
11). For instance, in Kermanshah (
10), the MRTS for physicians and active beds was 0.95, which indicated that a physician is replaced with 0.95 beds, and the production level remains constant. However, the MRTS for nurses-physicians was 0.26 and if a nurse is replaced by 0.26, the level of production remains constant. The MRTS for physicians-other staff, nurses-active beds, nurses-other staff was estimated at 10.96, 0.25, and 2.86, respectively.
The results of the review regarding the production function indicated that the production factors of elasticity were 0.64, 0.55, 0.36, 0.22, 0.047, and 0.0004 for active beds, nurses, other staff, physicians, virtual variable, and technology, respectively. Compared to the other inputs, active beds had the maximum effect on the hospital output as per a 1% increase in the number of the active beds, the number of patients increased by 64%. On the other hand, technology had the minimum effect on the hospital output as per a 1% increase in the number of technology, the number of patients increased by 0.04%.
The total elasticity of the production factors was estimated at 1.76, and the efficiency to the scale increased in this review. In addition, the physician input had the highest level of marginal production (53.22), and the nurse input had the lowest level of marginal production (32.56). The maximum and minimum levels of average production were 219.636 and 37.76 in physicians and other staff, respectively.