Validation of a questionnaire of knowledge and attitudes about the subcutaneous venous reservoir in nursing*

Objective: design and validate a questionnaire to evaluate the knowledge and attitudes of nurses about the subcutaneous venous reservoir. Method: pilot test: 30 specialized care nurses. Main study: 236 nurses of primary and specialized care. Content validity was evaluated by Lawshe index, reliability by test-retest, internal consistency by Cronbach alpha, and construct validity by exploratory factorial analysis. Results: Items with a Lawshe index lower than 0.51 were eliminated. In the test-retest, the intraclass correlation coefficient was higher than 0.75 for all items. The Cronbach alpha of the attitude questionnaire reached 0.865. The Cronbach alpha value for knowledge was 0.750. The exploratory factor analysis identified a set of four dimensions for each part that explain 64% (attitude) to 80% (knowledge) of variability. Conclusion: the analysis of the reliability and validity of the questionnaire supports its use as an instrument to assess the knowledge and attitudes of nurses towards the subcutaneous venous reservoir.


Introduction
The subcutaneous venous reservoir (SVR) is a type of central venous access fully implanted under the skin, consisting of a catheter and a component fixed by suture, suitable for children and adults, which ends in the superior vena cava or the right atrium and allows the administration of various therapeutic measures improving the quality of life of patients (1)(2)(3) .
The application of prolonged therapeutic guidelines intravenously for the treatment of various pathologies leads to a decrease in the patient's vascular network (4) .
That is why SVR is used and this fact implies that more and more nursing professionals are daily confronted with these devices, both in primary care and specialized care, and therefore competence in the management of SVR is necessary (5) .
The SVR should be considered the first choice for two reasons: the comfort it gives to the patients by avoiding the traumatic search for a vein, decreasing their level of anxiety and increasing their comfort, which improves their quality of life; and the care work of the professional who handles it by allowing a fast and safe venous access (6)(7) . A misuse of SVR can cause irreparable damage in it and therefore lead to the need for a replacement of the central access and damage to both the costs and the patient's quality of life (8)(9)(10) . It is essential to nursing staff handling these devices safely, requiring specific knowledge and attitudes (11) . Knowledge regarding the attitudes and level of knowledge of nursing professionals concerning the management of SVR is limited, and there are clear evidences about the problems in the use of these devices by the professional Nursing group. This situation also affects the comfort of patients with SVR (12)(13)(14)(15)(16)(17)(18)(19) .
The available studies mainly refer to the technique of    Raña-Rocha R, Lopez-de-Ullibarri I, Movilla-Fernández M-J, Coronado C.
To validate the content of the questionnaire, a set of aspects was considered in the evaluation of each question. In the attitude questionnaire, the four aspects were "Apprehension of the professional managing the SVR", "Fear of the professional to make mistakes managing SVR ", "Safety in the handling of SVR by the professional" and "Extrinsic hindering element for the use of SVR". In the knowledge questionnaire "Knowledge about the applications of SVR", "Knowledge about the handling of SVR", "Training on SVR" and "Quality of care provided to the patient" were evaluated. In addition, in each question a section of observations was included so that the experts could contribute.
Once the 14 questionnaires were collected, Lawshe's content validity index (CVI) was used to evaluate each item. In each of them, the four aspects proposed for that block of the questionnaire had to be evaluated individually as "not relevant", " little relevant", "quite relevant", "very relevant". As a criterion for excluding items from the questionnaire, it was decided to eliminate those that did not obtain a score greater than 0.51 in at least one of the aspects (22) . The questionnaire was repeated by eliminating the items that did not pass the CVI filter and Rev. Latino-Am. Enfermagem 2020;28:e3250.
To carry out the study, the confidentiality of the information has been guaranteed according to the regulations in force (26) Table 1 shows the minimum, maximum and median CVI values for each item of the attitude and knowledge questionnaires in the initial tool. Two questions were removed from the initial knowledge questionnaire because of the DVI calculation. The new version of the questionnaire was reduced to a knowledge block with 13 questions and an attitude block with 16. In the test-retest carried out for the reliability assessment in the pilot study, the ICC was greater than 0.75 for all items (Table 2). Cronbach's alpha, calculated with data from the first administration of the test, was 0.818 for the attitude questionnaire and 0.608 for the knowledge questionnaire. Similar values were obtained in the retest (0.819 and 0.642, respectively).

Results
The cross-sectional study for the evaluation of design validity and reliability was then carried out. 236 nurses from primary and specialised care participated in the study aimed at personnel from the Ferrol Health Area.
The response rate of specialised care nurses (80.1%) was slightly higher than that of primary care nurses (76.0%).
In the EFA of the knowledge questionnaire, 4 factors were identified, which explained 80% of the variance: "Training in the management of SVR" (items 3, 4, 5 and 6), "Theoretical framework of SVR management" (items 2, 9 and 12), "Influence of infrequent situations" (items 7 and 8), "Nursing competencies" (items 10 and 11) ( Table 3).       (13,15,19) . Other studies, focused on the well-being of the patients using the device, have contributed with respect to the dissatisfaction or discomfort they feel with the handling of their central pathway by the healthcare professionals who attend them (28) . It shows the deficit care of nursing staff (29) , and even indicate some possible area of improvement in the practice of the nursing professional (17,30) .
For all these reasons, we believe in the need to develop a tool that enables measuring the knowledge and attitudes that nursing professionals express when handling the device.

Conclusion
It is very important that nursing staff manipulate the subcutaneous venous reservoir (SVR) safely, and, for this purpose, they need specific knowledge and attitudes.
Some studies highlight the problematic use of these devices by the professional nursing group, a situation that also affects the well-being of patients with SVR.
No questionnaires measure the level of knowledge and attitudes of the nursing professional towards the use of SVR. Therefore, a validated tool was developed to measure the level of knowledge and attitudes of the nursing professional towards the use of SVR, both in primary care and in specialized care.