Background
Admissions to intensive care units (ICUs) are on the rise due to advancements in treatment options and the growing elderly population [1, 2]. During pandemic periods, such as coronavirus disease (COVID-19), the increasing demand for intensive care units, combined with the 24-hour dynamic and variable process, makes it challenging to manage the nursing workload [3, 4]. The increasing burden of nursing responsibilities in ICUs negatively affects both patient safety and the overall quality of healthcare [5‐7].
The evaluation of the cost-effectiveness relationship in the utilization of healthcare services in intensive care is inevitable. An important determinant of this relationship is intensive care nursing workload. However, reducing the workforce solely due to cost does not seem to be a rational approach. A diminished workforce, particularly in the monitoring and care of critical patients like those in intensive care, can have adverse effects on the duration of stay in the ICU. This reduction in service quality may lead to an unintended increase in costs, counteracting the intended goal of cost reduction. Therefore, intensive care nursing workload should be evaluated objectively [8].
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Numerous tools for evaluating nursing workload have been acknowledged in both national and international literature [9]. One of these assessment tools the Critical Nursing Situation Index (CNSI), was developed by Binnekade et al. The final version, consisting of 84 items, encompasses eight main sections related to nursing care in the ICU, which are mechanical ventilation applications, administered intravenous treatments, fluid therapy, cardiovascular system assessment, medical treatments, nutritional support, and the control of devices and connections [10]. The CNSI has been validated and adapted for use in our country, and it has been determined to be a valid and reliable scale for the Turkish population [11].
Another scoring system measuring nursing workload Therapeutic Intervention Scoring System-28 (TISS-28), was developed by Cullen et al. in 1974 [12]. The TISS-28 was designed to evaluate nursing workload in ICUs by taking into account the severity of patients’ illnesses. It was originally intended to undergo periodic reviews by a panel of experts. Before the development of specific tools for measuring illness severity, TISS-28 was employed to categorize patients according to the severity of their conditions. Additionally, TISS-28 found utility in assessing the utilization of hospital resources. In studies related to nursing workload and costs where TISS-28 is to be utilized, it is crucial to ensure the accuracy of the assumption that TISS-28 reliably measures nursing time devoted to patient care. The work of nurses in the ICU comprises various activities. Nurses allocate only 43.3% of their time to activities related to the items in TISS-28. Hence, nursing activities assessed with TISS-28 may not be accurately evaluated. To reduce potential inaccuracies in assessment, Miranda et al. introduced modifications to TISS-28, leading to the creation of the Nursing Activities Score (NAS) (see Appendix 1). NAS encompasses 80.8% of all nursing activities, surpassing the 43.3% coverage of TISS-28 [13]. In contrast, neither the TISS-28 nor the NAS despite their recognized high reliability and sensitivity in measuring nursing workload have been validated for the Turkish setting. As a result, there is a lack of locally validated versions of these scales, which limits their applicability in evaluating nursing activities or workload in Turkey.
The objective of this study was to assess the Turkish validity and applicability of the model, taking into account the capacity of NAS to gauge nursing workload in intensive care units.
Methods
The study was planned as a validation study. The study was completed in three intensive care units with a total of 34 beds, where similar patients were followed to avoid possible incorrect assessments. Patients over the age of 18 who spent at least 24 h in level 3 intensive care and full-time nurses who participated in the treatment of these patients, provided only direct patient care, and worked in the ward for at least 2 months were included in the study. Data from nurses who cared for patients under the age of 18, those responsible for patients scheduled for discharge from the intensive care unit within 24 h, and those who changed their workplace for any reason during their shift were excluded from the analysis. Data collection was conducted from May to November 2023. Approval was first obtained from the Hospital Directorate and Intensive Care Unit Supervisor, and local ethics committee approval Samsun University Clinical Research Ethics Committee (KAEK 2023-12/2) was subsequently secured. Furthermore, permission was sought and granted via email from the original developer of NAS. Following these approvals, the study was registered in the Protocol Registration and Results System (ClinicalTrials.gov NCT04928040) and was conducted in compliance with the principles outlined in the Declaration of Helsinki. The need for consent to participate was waived by our Institutional Review Board (Samsun University Clinical Research Ethics Committee (KAEK) 02.12.2023).
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Setting and sample
The purposive sampling method was used in sample selection in the study. In developing the scale, a sample size of 5–10 times the number of items in the scale is necessary for factor analysis in reliability and validity studies. Additionally, to conduct the test-retest method to examine its invariance over time, a minimum of 30 pairs of data is required [14]. In this study, considering that the Nursing Activity Score (NAS) consists of 23 items (n = 23), a total of 150 intensive care nurse shifts were evaluated with the NAS, which would be compatible with 5–10 times the number of recommended scale items. That decision was reached based on the suggestion that the number of individuals should be at least 5–10 times greater than the number of items in a scale when determining sample size for explanatory factor analysis in studies developed in different languages and/or cultures [15].
The study was conducted in three stages: (Fig. 1)
Fig. 1
Workflow diagram
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First stage
The translation process followed the method outlined by Guillemin, Bombardier, and Beaton [16‐18] involving translation, back-translation, and evaluation. The English version of the 23 items was initially translated into Turkish by three professional translation companies. The three translations were consolidated into a single text by an intensive care specialist. A council (formed by three intensivists) whose English proficiency was approved and whose native language was Turkish, compared the text with the original NAS text, resulting in the most appropriate Turkish translation (see Appendix 2).
The Turkish translation was again translated into English by three professional companies. The three translations were consolidated into a single text by an intensive care specialist. A council (formed by three intensivists) whose English proficiency was approved and whose native language was Turkish, compared this text with the original NAS text. The evaluation was conducted based on the degree of similarity (in percentage) of three variables to the main text. The arithmetic mean of the similarity percentages was calculated (see Appendix 3).
Second stage
A pilot study was planned after translating and retranslating the original text. It involved 30 nurses providing care to patients aged 18 years and above, admitted to Level 3 intensive care for at least 24 h. The study recorded the nurses’ professional experience, gender, reason for patient admission, Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score, mechanical ventilation requirement, need for renal replacement therapy, and requirement for inotropic treatment. Nursing activities based on the NAS were evaluated and documented during the nursing shift by an intensive care operations nurse and an anesthesia assistant doctor.
Third stage
Comparative study: The effectiveness of the translated NAS score was investigated by evaluating it together with the CNSI score, which has been validated and proven for Turkish, in terms of Turkish validation and validity. The study was conducted by two assessors through 150 nursing shifts involving individuals aged 18 years and above and who had spent at least 24 h in Level 3 intensive care. The study recorded various factors related to the nurses and patients. For nurses, gender, age, and professional experience were documented. Regarding patients, the reasons for admission to the ICU, SOFA score, and APACHE II score were noted. Furthermore, the study assessed patients’ requirements for mechanical ventilation, renal replacement therapy, and inotropic treatment. During nursing shifts, the NAS and CNSI scores were recorded by a nurse responsible for intensive care operations and an independent evaluator, and the correlation between the two scores was investigated.
Data analysis
The statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS) program, version 26 (IBM Corp., Armonk, NY, USA). The Kolmogorov-Smirnov test was employed for normality tests, and the Shapiro-Wilk test was used for subgroup analyses with sample sizes of 30 and below. For quantitative data with a normal distribution, the mean (± standard deviation) was presented, while for non-normally distributed data, the median (interquartile range) was utilized. Categorical data were presented using frequencies (and percentages). Comparisons between quantitative variables were conducted using Student’s t-test or the Mann-Whitney U test, while comparisons of categorical data were assessed using the Chi-square (χ2) test or Fisher’s exact test.
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In the pilot study, the reliability of Turkish translation variables for NAS validation was evaluated using the Cronbach’s alpha method, and inter-rater reliability was measured using Kappa statistics. The NAS and CNSI scores were examined using the Pearson correlation test. A Cronbach’s alpha result greater than 0.70 was considered indicative of good reliability among variables. For other tests, a p-value less than 0.05 was considered statistically significant.
Results
The study spanned 7 months and took place in three Level 3 ICUs. Over this period, a total of 1,651 patients were admitted to the intensive care units, with 74 nurses providing care during their hospitalization. Nurses worked either 8-hour shifts during the day or 16-hour shifts in the evening. The NAS validation study specifically conducted assessments during 8-hour daytime work periods.
The translation process involved three translations and three back-translations, resulting in a conformity rate of 96.9% when compared to the original text (see Appendix 3). Following 150 assessments, the NAS (%) value ranged from a minimum of 32 to a maximum of 119.8, with a calculated Mean ± SD of 90.2 ± 17.3.
After the pilot study, which included the assessment of 30 patients and 30 nurse shifts, an internal consistency Cronbach’s alpha coefficient of p = 0.718 was determined. This result prompted the commencement of the NAS and CNSI assessment study. The characteristics of the assessed nurses and patients throughout the study process are detailed in Table 1.
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Table 1
Nurse and patient characteristics
Nurse | |
Gender (female) n (%) | 83 (55.3) |
Age (years) mean ± SD | 31.6 ± 3.9 |
Years in profession | 9.1 ± 3 |
Patient | |
Gender (female) n (%) | 62 (41.3) |
Age (years) mean ± SD | 67.1 ± 12.3 |
APACHE II mean ± SD | 18.9 ± 6.3 |
SOFA mean ± SD | 5.6 ± 2.9 |
Admission ICU n (%) | |
PACU | 33 (22) |
Trauma | 36 (24) |
Intracranial hemorrhage | 33 (22) |
Ileus | 14 (9.3) |
Sepsis | 34 (22.7) |
Mechanical ventilation n (%) | 80 (53.3) |
Inotrop treatment | 61 (40.7) |
RRT | 34 (22.7) |
NAS (%) mean ± SD | 90.2 ± 17.3 |
CNSI (%) mean ± SD | 24.3 ± 3.5 |
The assessment of inter-rater reliability indicated a high level of agreement (99%) and an average Kappa index of 0.598 (p < 0.001). In the study evaluating 150 patient and 150 nurse shifts, the internal consistency Cronbach’s alpha coefficients for NAS were found to be 0.759 for assessor 1 and 0.767 for assessor 2.
Significant statistical correlations were identified between the average NAS measurements by two assessors and CNSI scores, as well as APACHE II scores (r = 0.71; p < 0.001, r = 0.80; p < 0.001), as evidenced by multivariate regression analysis (R2 = 83%, p < 0.001). The validity is substantiated by a statistically significant relationship between NAS and CNSI, as well as APACHE II scores. The relationship between NAS, CNSI, and APACHE II is illustrated in Fig. 2.
Fig. 2
Relationship of NAS, CNSI and APACHE II score
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Furthermore, a positive correlation was noted between NAS and patient age (r = 0.213, p = 0.009), as well as SOFA score (r = 0.417, p < 0.001). However, there was no significant association between NAS and patient gender (p = 0.131) or the reason for admission to the intensive care unit (p = 0.120).
Discussion
Precise calculation of nursing workload and the efficient organization of nursing activities can significantly decrease the risk of stress and burnout among ICU nurses. This, in turn, can lead to positive outcomes, including enhanced patient results and more optimized healthcare expenditures, achieved through the delivery of improved healthcare services. The study provided evidence of the Turkish validity and reliability of the NAS, a globally recognized measure of nursing activities that has been proven effective and reliable.
The calculated NAS results in the literature exhibit variations [19, 20]. In the study by Moghadam et al., NAS (%) was calculated as 72.84 (22.07) [21]. In the retrospective study conducted by Sardo et al., NAS (%) was found to be 67.5 ± 10.9 [22]. The calculation of NAS varies depending on the day it is assessed after patients are admitted to the ICU. Especially, NAS values calculated within the first 24 h after patient admission tend to be higher. In the same study by Sardo et al., NAS values (%) within the first 24 h were found to be 80.67 ± 10.89 [22]. In our study conducted in three level-3 intensive care units, where the working period was organized as 8 h during the day and 16 h in the evening and with a nurse serving two patients, NAS (%) was calculated as 90.2 ± 17.3. The calculated NAS in our study was found to be higher compared to the values reported in the literature. This could be attributed to the potential differences between nursing activities defined in our country and those in other countries. Furthermore, in the studies, nursing shifts are generally organized as 3/day (8 h during the day, 8 h in the evening, 8 h at night). In our country, however, nursing shifts are organized as 2/day (8 h during the day and 16 h in the evening). Additionally, our hospital is a significant level-3 healthcare center in the region. Therefore, our hospital is confronted with a high influx and burden of patients. Initially planned as a 400-bed center in 2010, our hospital is currently striving to provide services with a capacity of more than 1,000 beds. Due to these reasons, our NAS values may have been found to be higher compared to the literature.
Item 14 involves the calculation of the ratio of measurements taken during working hours for ‘Left Atrial Monitoring: Measurement of Cardiac Output in Patients with or without Pulmonary Artery Catheter.’ The monitoring and procedures are typically conducted by specialized cardiologists, anesthesiologists, or intensive care physicians in our center. Due to the inability of nurses to monitor the procedure, except for continuous monitoring with some invasive monitoring, all evaluations for ıtem 14 were considered as 0% when calculating the NAS. Item 15, ‘Cardiopulmonary resuscitation (excluding a single precordial thump) in the last 24 hours after arrest’ was scored as 0% for all evaluations during the study period, as there were no admissions of patients after arrest in our ICUs. Due to not being within the scope of the job description, ıtem 16, titled ‘Techniques of hemofiltration, dialysis techniques,’ was scored as 0 or with low percentages, as it is generally performed by dialysis technicians in our center and in our country, specifically for patients requiring hemodiafiltration. Item 18, titled ‘Intracranial pressure measurement,’ is generally monitored in our center using non-invasive methods such as ultrasound. In this monitoring, similar to the left atrial pressure monitoring, due to the requirement for a certain level of expertise, the measurement and monitoring are not conducted by the nurses who participated in the study. All evaluations within this parameter were scored at 0%.
Various reasons contributing to increased nursing activities in intensive care units have been identified. Rivera et al. demonstrated that a high APACHE II score, the monitoring of trauma patients, and the need for intensive care stay exceeding 3 days are associated with increased nursing activities [23]. In another study conducted in Brazil, it was shown that patient age is associated with an increase in NAS [24]. In our study, a high correlation was observed between APACHE II and NAS, a moderate correlation between SOFA score and NAS, and a weak but significant correlation with patient age.
Limitations
The study has various limitations. The inclusion of a nurse as one of the assessors may have led to a potential bias, resulting in inflated scores. However, statistical analyses and the comparison of two different scoring systems by a non-nurse evaluator yielded significant consistency and reliability. Furthermore, in our country’s healthcare system, the APACHE II score is calculated following the initial admission of patients. The APACHE II score was calculated by impartial physicians who did not participate in the study. We believe that the support of NAS validation reliability by the APACHE II score eliminates the potential for bias. Items 14, 15, 16, 18, 20, 21, 22, 23 were scored as more than 0 for more than two intervals due to both the absence of these tasks in the job description of the nurses who participated in the study and the impracticality of their application within the relevant shifts because of patient characteristics. Therefore, factor analysis could not be conducted in the study.
Conclusion
The study findings suggest that the NAS is a valid and reliable tool for measuring nursing workload in Turkish ICUs. These results carry implications for improving the assessment and management of nursing activities, ultimately contributing to enhanced patient care in the intensive care setting.
The Turkish version of the Nursing Activity Score is presented in Appendix 4.
Acknowledgements
We express our gratitude to Prof. Dr. Ender Gedik, who evaluated three Turkish translations after translating from English to Turkish and transformed them into a single text. Additionally, we thank the esteemed scientist Prof. Dr. Dinis dos Reis Miranda, who introduced us to NAS with the article published in 2003. After planning the study, we had the honor of contacting him, even if through email, and he permitted us to conduct the study. Unfortunately, with great sadness, we learned that Prof. Dr. Dinis dos Reis Miranda passed away on November 4, 2023. We extend our deepest respects to him.
Declarations
Ethics approval
The need for consent to participate was waived by our Institutional Review Board (Samsun University Clinical Research Ethics Committee (KAEK) 02.12.2023).
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Consent to participates
Not applicable.
Trial registration number
Samsun University Samsun Training and Research Hospital, following ethics committee approval (Samsun University clinical research ethics committee (KAEK) 2023-12/2) and Clinical Trials (NCT04928040) registration.
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