The validation and inter-rater reliability of the Serbian translation of the Richmond agitation and sedation scale in post anesthesia care unit patients


Hippokratia 2016, 20(1):50-54

Stasevic Karlicic I1, Stasevic M1, Jankovic S2, Djukic Dejanovic S1,3, Dutina A1, Grbic I1
1Clinic for Psychiatric Disorders “Dr Laza Lazarevic”, Emergency Department, Belgrade, 2University Clinic for Pharmacology, Toxicology and Clinical Pharmacology, Faculty of Medical Sciences, 3Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia


Background: Targeted light sedation is recommended because it shortens the time of mechanical ventilation and the length of stay in an intensive care unit (ICU). However, there is no validated scale for sedation and agitation in ICU in the Serbian speaking area. The aim of the current study was to validate, verify the reliability and enable the application of the Richmond Agitation and Sedation Scale (RASS) in the Serbian speaking area. Methods: In this prospective cohort study, RASS was applied to 301 adult patients hospitalized in surgical ICUs by two different research team members. We tested RASS for inter-rater reliability by the correlation between them. The scale was validated by comparison to Glasgow Coma Scale (GCS) scores which was applied by the third investigator. Interrater agreement was measured using weighted kappa (k) and for correlation Spearman’s test was used. Results: The inter-rater reliability of the scale was high (k ˃0.7). The degree of correlation between the RASS and the GCS during all five days of observation was high (˃0.7 for both investigators, the fifth day). In all the cases, Spearman’s correlation coefficient was highly significant (p ˂0.01). Conclusions: The Serbian translation of the RASS is a reliable and valid instrument for the assessment of the levels of sedation and agitation with patients in ICU. Hippokratia 2016, 20(1): 50-54

Key words: Richmond Agitation and Sedation Scale, intensive care unit, inter-rater reliability, validity

Corresponding author: Ivana Stašević, Clinic for Psychiatric Disorders “Dr Laza Lazarević”, 26 Višegradska street, Belgrade, tel: +38163222832, е-mail:


Sedation is an integral part of treatment in an intensive care unit (ICU)1,2. The protocols of targeted light sedation shorten the time of mechanical ventilation and the length of stay in ICU, and they are significant for preventing and treating delirium3-7. In order to improve the outcome of the patients’ treatment, it is recommended that a standardized protocol of analgesia and sedation should be introduced, which also includes the application of validated scales for the assessment of sedation8-12.

The Richmond Agitation-Sedation Scale (RASS) is a suitable staff-scored instrument for application by the hospital bed for the purpose of monitoring the levels of sedation and possible changes in the behavior of critically ill patients in ICU13-15.

The aim of this study was to validate, verify the reliability and enable the application of the RASS in the Serbian speaking area and cultural milieu.

Material and Method

Instrument description

The RASS is a ten-level scale developed by a multidisciplinary team at Virginia Commonwealth University in Richmond (Table 1)13. Four levels denote the levels of anxiety or agitation [from +1 to +4 (combative)], one level denotes calm and alert state (0), and five levels denote the levels of sedation [from -1 to -5 (unarousable)]13,16. The Serbian translation of the values and definitions for each level of agitation and sedation, as well as the instructions for assessment, are displayed in Table 2. Excellent inter-rater reliability has been demonstrated for the RASS on a large sample of adult patients in three surgical ICUs, as well as excellent validity in comparison to selected scales for the assessment of sedation13,14,16,17.


Translation and cultural adaptation of the RASS were made according to the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines18. The original scale was first translated into Serbian by two independent translators, who were not members of the study team. They translated the scale independently of each other, and then the translations were harmonized into one Serbian version at the meeting of the study investigators and the translators. The harmonized Serbian version was then translated back into English by a native English speaker who was not aware of the original English version of the RASS. The back-translation into English was then compared with the original English version by the study investigators, and at the new meeting of investigators, the final Serbian version of the RASS was agreed on. The final translation of RASS into Serbian was then tested on five physicians for clarity and comprehension. After the pilot, a few minor changes were made, and then the final Serbian version of RASS was copied and prepared for inter-rater reliability and validity testing.

Population and settings of the study

This prospective cohort study included 301 patients from the surgical intensive care units of the Clinical Centre of Serbia in Belgrade; Post-Anesthesia Intensive Care Unit (PAICU) of the Abdominal Surgery clinic, PAICU of the Orthopedic clinic and PAICU of the Abdominal Surgery department of the Emergency centre. All of these ICUs had 12, 9 and 39 beds respectively. The study was approved by the local Ethical Committees of the clinics where the research was conducted (respectively; No 215/ 28.1.15. No 01- 446/ 6.2.15. No 695/ 19.2.15). We obtained written informed consent from all patients or their relatives. The respondents were recruited by the method of successive sampling. The sample included all ventilated and non-ventilated patients that had spent more than 24 hours in the PAICU and that were treated during the period from 2 February 2015 to 12 March 2015. Hearing-impaired and vision-impaired patients, as well as patients not speaking Serbian, were excluded from the study. The following variables were observed: age, gender, diagnosis, type of surgery (elective or emergency) and the presence of mechanical ventilation.


Two investigators, after three days’ training time, independently of each other, applied the Serbian translation of RASS in an ICU. The rating was conducted during five days at the most, always in the same period of the day (from 03.00 p.m. to 05.00 p.m.), in agreement with the instructions defined by the same team that had developed and validated the scale in the English speaking area, already displayed in Table 1. There was no other formal training recommended by the author13,14,16.

As gold standard the investigators evaluated the respondents in the same period, independently of other participants in the study. As well as in the studies of other validators13,14,17, the Glasgow Coma Scale (GCS) has been used19 as gold standard. It was applied by the anesthesiologists in ICUs where RASS was validated.

Validation and inter-rater reliability

The validation of the Serbian translation of the RASS was performed based on the comparison of the results obtained by applying this scale with the results obtained by applying the scale used as the gold standard.

The inter-rater reliability of the instrument was obtained as a result of comparing the scores of the Serbian translation of the RASS obtained by the two investigators.


The inter-rater variability between the two raters was determined with the use of Cohen’s kappa coefficient (k). The reliability of the questionnaire was assessed through the calculation of the coefficient of correlation between the score of the RASS scale and the score of the GCS; Spearman’s correlation coefficient was used because the data were not normally distributed. For the statistical analysis, the Statistical Package for the Social Sciences (SPSS) software (IBM Corp., Armonk, NY, USA) version 18, with the level of statistical significance p =0.05, was used.


The study included a total number of 301 respondents. The baseline characteristics of the respondents are shown in Table 3. The inter-rater reliability of the scale was high (k ˃0.7) (Table 4). The degree of correlation between the RASS and the GCS during all five days of observation was high (˃0.7 for both raters, the fifth day). In all the cases, Spearman’s correlation coefficient was highly significant (p ˂0.001) (Table 5).


The only scale that measures the quantitative decrease in the level of consciousness, translated for the Serbian speaking areas is the GCS20. It is designed primarily for the needs of the clinical neurosurgical practice, for quantifying decreases in the level of consciousness in the patients who have experienced head traumas19. Due to a lack of other instruments, the GCS is widely used in neurological, psychiatric, surgical and general medical intensive care units. The introduction of the RASS in clinical practice enables the measurement of both quantitative level of consciousness and agitation level of patients hospitalized in ICU.

This is the first study of reliability and transcultural validation of the RASS in the Serbian speaking areas. Our study has shown a high degree of inter-rater reliability (r ˃0.7), which corresponds to the results of other similar studies (r =0.64-0.91)11,13,14. Furthermore, there has been a high degree of compliance with the “gold standard”, i.e. the scores of the RASS from -5 to 0 are highly correlated with the scores of the GCS (r ˃0.7; p ˂0.001). Similar results have been obtained by other authors as well; Nassar et al (r =0.7; p ˂ 0.001) and Elly (r =0.91; p ˂0.01)14,17.

In addition to being reliable and valid, the scale can be easily applied by the hospital bed, i.e. it can be applied by a large team of professionals (physicians and nurses) for a time shorter than 20 seconds, after simple training, through three steps: observation, verbal and physical stimulation13,14. In this way, the RASS scores the levels of sedation or agitation that are determined by the patient’s response to physical/verbal stimulation. Apart from its extreme significance for determining the levels of sedation in patients for the purpose of finely titrating analgosedation therapy, the scale can also be used for the early detection of delirium in ICU patients21,22. It is known that there is a high degree of association between the presence of delirium and poor outcomes, including death in ICU patients20,23,24. In addition, the oversedation of patients in ICU correlates with adverse outcomes such as longer stay for treatment, delirium, and death25. The use of valid instruments, such as the RASS, contributes to easier and faster determination of the levels of sedation and thus to a more precise dosage of analgosedation12,13,17,19,25. Furthermore, as it easily detects and quantifies changes in behavior (from the calm state to extreme agitation), it can have wide application and significance in the early detection of delirium whose prevention contributes to better prognosis and treatment of critically ill patients23,24,26. It is especially practical for application in intubated patients because we can detect delirium even without a clinical psychiatric examination by using the RASS. A shortcoming of the instrument is that it cannot be applied to hearing impaired and vision impaired patients.

There are several potential limitations of our study. First, the investigators were only trained for a short period of time before applying the scale. Perhaps if our training had been longer, the inter-rater agreement could have been greater. Second, in the statistical analysis, we did not take into account the total number of observations, but we only compared the daily scores. Last, our team consisted of only three investigators.

In conclusion, the Serbian translation of the RASS has proved to be a reliable and valid instrument for the assessment of the levels of sedation and agitation of patients in ICU. Also, there has been a high degree of correspondence between the investigators. As such, it can be valuable in clinical practice, for the titration of the dose of analgosedation within the protocols and interventions aimed at reducing the adverse effects of oversedation and agitation on the further course of treatment and prognosis for seriously ill patients.

Conflict of Interest

Authors report no conflict of interest


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