Qualitative Phase

In this phase, researchers explored participants’ perceptions and experiences about the competence that nurses need for participation in disaster response using a content analysis method. Purposeful sampling with maximum variations (in age, education level, and occupation) was used and 35 Iranian nurses and managers with recent experience of the medical response to disasters participated.

The mean age of the 35 participants was 37.5 y, and 30 of them were men. Participants had between 7 and 28 y of nursing experience in, and recent experience of, the medical response to disasters (Table 1).

Table 1.

Demographic characteristics of participants in the qualitative stage

Face-to-face unstructured interviews explored the participants’ experiences and their perceptions of the competencies required by nurses in a disaster setting. The time and place of the interview were arranged according to participants’ preferences. At the beginning of interviews, written informed consent was obtained from the participants. After 30 semi-structured interviews, data were saturated, and 5 more were completed to confirm the chosen categories. The interviews lasted 40-100 min with a mean length of 1 h and were recorded using a digital voice recorder. Each interview began with the question, “Please tell me about your experience of providing care in a disaster.” Nurses’ responses were clarified and expanded upon by follow-up questions. The interviews were transcribed word by word, and qualitative conventional content analysis was conducted. The data obtained were simultaneously processed using the 5-step content analysis method of Granheim and Lundman. ^{Reference Graneheim and Lundman23} Transcripts were read line-by-line, the important sentences and phrases were underlined, and the main ideas derived from them were labeled as codes. Overlapping codes were assimilated, and primary categorization of data was performed. Data reduction continued in all analysis units until the main categories emerged. ^{Reference Streubert and Carpenter24} Two researchers’ expert in qualitative research reviewed the transcript and consensus was achieved. When similar categories emerged, they were merged into main themes. Five themes emerged from the qualitative study: (1) management, (2) legal and ethical, (3) team work, (4) specific personal, and (5) technical competence (Table 2).

Table 2.

Themes, main categories, and subcategories emerged in the qualitative phase

Quantitative Phase

The first step was development of a prototype tool, with the assistance of an expert panel. An item pool was extracted from the qualitative interviews. This initial item pool was comprised of 140 items in 5 categories. Then an extensive literature review was completed, and some items (25 items) that were not extracted from the qualitative study were added to the pool, resulting in 165 items in this phase. In the next step, the 165 items were discussed and assessed in a focus group with 14 emergency nurses; as a result, 38 items were merged with other items or deleted. The demographic characteristics of participants is presented in Table 3.

Table 3.

Demographic characteristics of emergency nurses in the quantitative phase

The developed prototype tool with 127 items was sent to 14 experts, 10 of them were PhD qualified nurses and 4 were experts in scale development. Feedback from this expert panel was used to identify items that should be merged or deleted. Two independent reviews were carried out to select the questions that were appropriate, accurate, and interpretable. Items were either accepted, rejected, or modified based on a majority opinion.

Regarding the 127 items in the first draft of the prototype tool, a total of 40 comments were received from experts. The researchers held a meeting to discuss these comments. As a result of the discussion, a total of 47 items were accepted, and their wording was revised as suggested; 28 items were merged into 13 items. Another 67 items were regarded as irrelevant by 8 experts or did not meet the criteria for a consensus and were deleted as suggested. The prototype tool was reduced from 127 to 60 items after these steps and was ready for psychometric testing.

Step 2 was psychometric testing. Ten emergency nurses were asked to evaluate the questionnaire and score the importance of each item on a 5-point Likert scale to calculate the Item Impact Score. The same emergency nurses were also asked about the relevancy, ambiguity, and difficulty of the items; and some minor changes were made to the preliminary tool. For calculating the Content Validity Ratio (CVR), the expert panel was asked to evaluate each item using a 3-point Likert scale: 1 = essential, 2 = useful but not essential, and 3 = unessential.

For calculating of the Content Validity Index (CVI), the same panel was asked to evaluate the items according to a 4-point Likert scale on relevancy, clarity, and simplicity. In this step, 4 items returned a CVI less than 0.79 and were deleted. The pilot version of the tool, consisting of 56 items, was prepared for construct validity testing. Exploratory Factor Analysis (EFA) was used for assessing the construct validity of the tool. In the first stage, the adequacy of sampling was evaluated by the Kaiser-Meyer-Olkin (KMO) Test; which was 0/941. The KMO value is between 0 and 1, and higher values show better factor analysis. ^{Reference Weller, Groffik and Chuch25} In addition, to determine whether the obtained correlation matrix was significantly different from 0, the Bartlett Sphericity test was used. Its value was 14,400 (P < 0.001) and demonstrated the ability of the items to be used to perform the analysis factor.

In this step, 6 items were deleted from the tool due to a factor loading below 0.4, and cross-loading. The prototype tool, with 50 questions, was then distributed to 430 nurses, comprising the nursing population working in emergency wards of the tertiary hospitals in 6 disaster prone cities in Iran. Four hundred nurses completed their assigned task and completed the questionnaire.

Their age ranged from 23 to 54 y (M = 33.6 y; SD = 6.6), and their work experience ranged from 2 to 30 y (M = 9.2; SD = 6.2).

Exploratory factor analysis loaded the 50 remaining items into 4 domains named management, legal and ethical, specific personal competence, and technical competence. Teamwork competence was merged with the personal domain in the quantitative phase resulting in 4 domains at the completion of this phase.

For reliability analysis, internal consistency was evaluated by Cronbach’s alpha coefficient. The Cronbach’s alpha was 0 .96 overall and ranged from 0.91 to 0.97 for the categories (Table 4).

Table 4.

Reliability of the factors

Abbreviations: CI, confidence interval; ICC, interclass correlation coefficient.

In addition, a sub-sample of disaster nurses (n = 30) completed the questionnaire twice, with a 2-wk interval to examine the stability of the scale by calculating the interclass correlation coefficient (ICC). The ICC was 0.99. Weller (2012) assert that an ICC of 0.4 or above is considered acceptable indicating an appropriate stability. ^{Reference Weller, Groffik and Chuch25}

The final tool consists of 2 parts. The first part addresses the demographic characteristics of the user and the second part consists of 50 questions, 44 of which, rated on a 5-point Likert scale from very high (5) to very low (1), assess the management competency (questions 1-12), specific personal competency (13-21), and technical competency (22-44) and, 6 of which (45-50), rated on a 4-point Likert scale from rarely (1) to always (4) assess the level of ethical and legal competency of nurses in disaster health relief. ^{Reference Veenema, Griffin and Gable16} The minimum and maximum attainable scores in all domains are 50 and 244, respectively; obtaining a higher-than-average score indicates the optimality of nurses’ disaster health competencies.

At the end of the quantitative phase, the questionnaire, consisting 50 items, was distributed among 200 nurses from 6 educational hospitals in Isfahan (a state in the central part of Iran) in 2015, using convenience sampling. The inclusion criteria were: Registered Nurse with at least 1 y of clinical experience and working in an emergency ward.

Ethical Considerations Ethics Committee at Isfahan University of Medical Sciences approved the study (No 390133). The participants were informed about the study and assured of confidentiality and anonymity. Participants in all stages of study gave written consent, and it was made clear that a participant could leave the study at any time without penalty.