Most participants (94.5%) were female, 61.2% were between the ages of 20–29 years, 53.7% were married, 72.7% had a Bachelor’s degree, and 54.9% had 1–5 years of professional experience. Furthermore, 79.2% of the participants reported that they had received training or courses on medication safety, 79.5% reported that medication administration principles were followed in the clinic where they worked, and 76.7% stated that medication administration was performed following the hospital’s medication administration rules and procedures (Table 1). The results of the methodological and descriptive stages of the study are provided in the following two sections.
3.1. Results of the Methodological Stage
The scale was translated into Turkish by four translators who were native Turkish speakers and fluent in English. The researchers then combined the four translations into a single form. In the second stage, this form was translated back into English by an expert who was not one of the previous translators.
The expert review was conducted by nine instructors and two nurses with master’s degrees. The I-CVI ranged from 0.80 to 1.00, and the S-CVI was 0.98. To assess the face validity of the Turkish form, a preliminary application was performed with 20 nurses. To ensure that they were comprehensible in Turkish, the expression “human factors” in the item “Understanding the role of human factors, such as fatigue, that affect medication safety” was changed to “personal factors”, and the expression “understanding the role” in “Understanding the role of environmental factors such as workflow, ergonomics, and resources, which affect medication safety” was changed to “understanding the effect”. With these adjustments, the scale form adapted to Turkish was finalised.
The results of CFA are shown in Table 2. The fitness indices of the original scale (model 1) (χ2/df = 1921.97/579 = 3.32, RMSEA = 0.067, CFI = 0.98) were determined to be at an acceptable level. However, modification indices were examined, and the original scale was modified sequentially as follows: item 28 and item 31, item 25 and item 31, item 10 and item 11, respectively. The fitness indices of the final scale (model 2) were as follows: χ2/df = 3.00, RMSEA = 0.062, CFI = 0.99, NFI = 0.98, GFI = 0.78, AGFI = 0.74, PGFI = 0.67, and PNFI = 0.89. The standard loadings of the items in the final scale ranged from 0.46 to 0.83. The squared multiple correlations (SMC-R2) ranged from 0.21 to 0.68 (Table 3).
The modification of model 2 was achieved by freeing the error terms (permitting correlated errors) of the items without excluding any items. Furthermore, the fit indices attained in both models were acceptable. Nevertheless, model 2 exhibited superior χ2/df and RMSEA values, indicating that it outperformed model 1.
For convergent validity, the CRs ranged from 0.68 to 0.79 and were higher than the AVE values (0.40 to 0.60). The correlation between factors ranged from 0.687 to 0.868 (Table 4). Item analyses revealed that the item-total correlations were between 0.46 and 0.77 (Table 3). A statistically significant difference (t: −30.601, p < 0.001) was observed between the mean scores of the groups with the lowest 27% of scores and the highest 27% of scores.
As shown in Table 4, the Cronbach’s alpha coefficient of the scale was 0.97. The split-half reliability was 0.912, and the test–retest reliability (ICC) was 0.939.
3.2. Descriptive Phase Results
The mean MSCS score was 4.106 ± 0.59, indicating a high level of medication safety competence. Among the subdimensions, the lowest score was obtained in the RNP dimension (3.959 ± 0.68 points) and the highest score was obtained in the PCMM dimension (4.246 ± 0.57 points) (Table 4). Table 5 presents the comparison of participants’ the of medication safety competence according to their demographic characteristics.
No differences were observed in the participants’ the of medication safety competence according to gender and the type of clinic they worked in. However, significant differences were found according to age, marital status, educational level, professional experience, and the type of hospital in which the nurses worked. Participants aged 40 years and older had higher the of medication safety competence than those aged 20–29 years; married participants had higher than single participants; and those with health vocational school and postgraduate degrees had higher than those with undergraduate degrees. In addition, nurses who received training or courses on medication safety, those who thought that the principles of medication administration were followed in the clinic where they worked, and those who thought that medication administration was performed following the hospital’s medication administration rules and procedures had higher the of medication safety competence (p < 0.05).