This cross-sectional study was carried out among 100 orthopedic resident and 100 nursing students of Iran University of Medical Sciences, during year 2015 and 2016. The rules of thumb, such as five or ten participants per item, was used for the sample size calculation.
Convenience sampling method was used to select subjects. Earlier, a 15-item questionnaire was used in the assessment of attitude toward healthcare teamwork in medical sciences. The aforementioned questionnaire was developed by Hacket, Rode, and Cox (2015). Questions one to ten were scored on the basis of a Likert scale, i.e. from highly agreeable to highly disagreeable. Questions 11 and 12 were graded on the basis of weak, fair, good, very good, and excellent grades, and questions 13, 14, and 15 were scored on a different basis. For example, question 13 was scored on basis of never, seldom, sometimes, often, and more often grades, question 14 was scored on basis of grades, such as not important, of little importance, moderately important, and very important; and question 15 was scored on the basis of one to two times, three to four times , five to six times, seven to eight times, and nine times and above (
4).
After obtaining permission from the main designer, the questionnaire was translated to Persian by two famous translators in both Persian and English literature. Then, it was compared to its original version and the gap between these two was removed. The statistical population of this research was medical sciences and nursing students. Content and face validities of the questionnaires were investigated by the experts’ panel (10 experts). Then, face validity was assessed by the subjects’ opinions. Content validity was assessed by the content validity ratio (CVR) and content validity index (CVI).
For this purpose, expert opinions were taken during CVR calculation to check whether an item is necessary for operating a construct in a set of items. The CVR Formula was

Equation 1.
where ne is the number of experts, who pointed to “essential” and N is the total number of experts. Then, the obtained score was compared to the Lawshe table. The acceptable level of CVR in the Lawshe table was determined to be 0.49 for 15 panelists; therefore, all items with CVR higher than 0.49 would remain in the instrument.
The CVI calculation was done based on panel rating on instrument items, which was related to its clarity and relevance for the underlying study construct, according to the theoretical definitions. For this purpose, experts were requested to rate each item for clarity and relevance. Then, ratings as relevant or clear (rating three or four) was divided by the number of experts. A CVI score of < 79% for each item was considered appropriate. If it was between 70% and 79%, it needed to be revised and less than 70%, it was omitted (
16).
To determine the instrument’s reliability, test–re-test was used and for internal consistency, Cronbach’s alpha was determined by the SPSS software version 19. P values of 0.05 were considered significant.
For constructive validity, explanatory factor analysis (EFA) was conducted using data from 200 subjects. The researchers also conducted confirmatory factor analysis (CFA) using several models of fit indices with the LISREL software: comparative fit index (CFI), lewis index (TLI), root mean square error approximation (RMSEA), and standardized root mean square residual (SRMR). Furthermore, CFI and TLI values above 0.9, and RMSEA and SRMR below 0.08 were considered as acceptable fit.