This quasi-experimental study aimed to evaluate the effect of two educational methods, mastery learning, and lectures, on oxygen therapy knowledge and practice of 50 nurses of a teaching hospital in southern Iran. The participants were selected using convenience sampling. To do so, the Continuing Education Center informed the nurses of the training program. Afterward, the enrolled nurses were randomly placed in the two intervention (mastery learning) and control (lecturing) groups. The inclusion criteria were the willingness for voluntary participation in the study and having at least three years of service records as a nurse. The exclusion criterion was the failure to attend the training sessions regularly. The data collection instruments were a demographic information questionnaire, the Nurses’ Oxygen Therapy Knowledge Inventory, and the Nurses’ Oxygen Therapy Practice Inventory. The demographic information questionnaire contained 7 items that assessed the participants’ age, gender, place of residence, marital status, education, clinical records, and the name of the clinic or ward. The Nurses’ Oxygen Therapy Knowledge Inventory was a research-made tool that was developed using books and articles in nursing principles and skills (1, 3) and contained 20 four-choice items (e.g., What is the right decision for a patient who needs oxygen at your diagnosis but the doctor has not prescribed oxygen for him/her?). The total score on the inventory ranges from 0 to 20. To calculate each respondent’s score, the sum of the scores of the 20 items was calculated and then divided by 20 (the total number of items). Accordingly, the respondent oxygen therapy knowledge was assessed using four quartiles (25, 50, and 75 percentiles). Accordingly, a score of less than 25 indicated poor oxygen therapy knowledge, a score of 25 to 50 indicated moderate oxygen therapy knowledge, a score of 50 to 75 indicated good oxygen therapy knowledge, and a score of higher than 75 indicated excellent oxygen therapy knowledge. Moreover, the Nurses’ Oxygen Therapy Practice Inventory was developed following a review of previous studies in the literature (2, 12, 13) and contained 20 items (e.g. I check the patient’s breathing rate and depth before administering oxygen) that measured the nurses’ oxygen therapy practice on a five-point Likert scale (always, often, sometimes, rarely, and never). The total score on the inventory ranges from 0 to 80. To calculate each respondent’s score, the sum of the scores of the 20 items was calculated and then divided by 20 (the total number of items). Then, the respondent oxygen therapy practice was assessed using four quartiles (25, 50, and 75 percentiles). Hence, a score of less than 25 indicated poor oxygen therapy practice, a score of 25 to 50 indicated moderate oxygen therapy practice, a score of 50 to 75 showed good oxygen therapy practice, and a score of higher than 75 suggested excellent oxygen therapy practice.
The content validity of the nurses’ oxygen therapy knowledge and practice inventories was assessed and confirmed by 10 faculty members of the School of Nursing. It should be noted that the content validity of the instruments was assessed both qualitatively and quantitatively by 10 nursing faculty members who had a history of teaching oxygen therapy. Accordingly, the items in the inventories were revised based on the feedback received from the faculty members. The quantitative content validity was assessed using the content validity index (CVI) and content validity ratio (CVR). To calculate the CVR, the items in the inventories were assessed by 10 nursing faculty members and they checked the necessity of each item (1 = Necessary, 2 = Useful but not necessary, and 3 = Not necessary). Thus, the items with CVR less than 0.7 were removed. To measure the CVI, the experts were asked to determine how relevant each item was. A score of 0.7 or higher was considered acceptable (20). Moreover, the face validity of the instruments was checked by 10 nurses. To measure the reliability of the instruments, Cronbach’s alpha coefficient was calculated which was 0.87 in a pilot study on 20 nurses.
The content of the training program was prepared based on the books on nursing principles and skills. The instructional content covered topics on various issues including the use of oxygen therapy devices (nasogastric (NG) tubes, simple face masks, venturi masks, masks with inhaled oxygen exhalation, etc.), the adjustment of the amount of oxygen according to the doctor’s instructions, checking the patient’s airway, performing respiratory physiotherapy and incentive spirometry, checking hypoxia symptoms, oxygen therapy complications, determining the patient’s oxygen saturation with a pulse oximeter, and oxygen poisoning symptoms.
Before starting the intervention, written consent was obtained from all participants and some information was given to them about the training program. The participants in both groups completed the questionnaires. A 30-minute briefing session was held for the participants in the intervention group to make them familiar with the training protocol. Afterward, the intended nursing skills were instructed to the participants in the intervention group using the mastery learning method through interactive lectures and questions and answers. The instructions were provided by an emergency medicine physician and a nursing professor. At the end of the training sessions (4 training sessions each lasting 1.5 hours), the post-test was administered to the group members. The individuals who scored less than 80% of the total score were trained individually. Individual training continued until all members obtained at least 80% of the total grade and gained complete mastery over the topics covered in the training sessions (13). Furthermore, the same educational content was instructed through lectures to the participants in the control group. One week and also three months after the training sessions, the participants in both groups completed the questionnaires and the results were compared.
In this study, continuous variables were described with the mean, standard deviation (SD), median, and interquartile range (IQR), and categorical variables were measured using frequency and percentage. The chi-square test was applied to test the possible associations between the categorical variables. The normality assumption of continuous variables was rejected by the Shapiro–Wilk test (P value < 0.05). Thus, the Mann-Whitney U test was applied to compare the means of the two groups. Moreover, the nonparametric covariance analysis (ANCOVA) (Quade Method) was used to test the effect of an independent variable (the variable with 2 intervention and control groups) on a continuous dependent variable (nurses’ practice or knowledge) by controlling the effect of the nurses’ practice or knowledge scores in the baseline time. In addition, the Friedman test and Dunn's pairwise post hoc tests were applied to detect significant differences between the means of the dependent variable at 3-time points. A P < 0.05 was considered statistically significant and the data were analyzed by SPSS software.