Development of a questionnaire assessing nursing staff’s knowledge, attitude, and practice on the prevention of the nosocomial infection in elderly patients: testing reliability and validity^†

To ensure the reliability and validity of the questionnaire, interviewees should be 5–10 times¹³ the number of questionnaire items. The sample size should be further expanded by 10.00%, given the possibility that there may be invalid responses and given the conduct of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). There are 38 items in the final version of the questionnaire. 700 copies are distributed and 692 (98.86%) collected. Excluding invalid questionnaires, 681 are left with an efficiency rate of 97.29%, which is in line with the designated sample size. The 681 copies are then randomly divided into two groups (N1 = 341, N2 = 340).

Sample inclusion criteria: (1) Nurses who have worked in the adult clinical department for >1 year and obtained the nursing qualification certificate, and (2) nurses who voluntarily participate in the study.

Sample exclusion criteria: (1) Interns, visiting students, students who have not passed the Standardized Training of Residents exam and those who have not yet obtained professional qualification certificates, and (2) nurses working in such departments as pediatrics, neonatology, obstetrics, and gynecology, without elderly patients.

The feasibility of this questionnaire is determined by a pilot study of approximately 30 subjects.¹⁸ The points to consider while determining feasibility include time taken to fill the questionnaire, simplicity of the format, clarity of the questions, ease of scoring, and result interpretation. Thirty copies of the questionnaire were distributed following a convenience sampling method to nursing staff for a pilot study with 14–17 min for filling-in. The preliminary survey turned out to be satisfying since all of the mentioned aspects were acceptable to participants.

The questionnaire consists of two parts: participants’ sociodemographic information (department, gender, age, education, professional title, years of service, etc.) and their knowledge, attitude, and practice in relation to the prevention of nosocomial infections in elderly patients. 18 items are designed for assessing nurses’ knowledge in this regard (1 = right answer, 0 = unanswered or incorrect answer). 10 items review nursing staff’s attitude through a Likert-4 scale (4 = very important, 1 = least important). For the rest of the 10 items, participants’ practices are evaluated with “never,” “sometimes,” and “always.” The three options are counted 1, 2, and 3 points, respectively. Notably, there are “reversed items” in this dimension, meaning the higher the score is, the better the nurse’ s practice is towards infection prevention in elderly patients.

In this study, six trained investigators who were evenly grouped into 3 sub-groups, participated in distributing and collecting the questionnaires. When investigators handed out the questionnaires, they explained the purpose and precautions of the investigation to the respondents. After the respondents filled out the questionnaires, they recalled them on the spot, numbered each copy, and excluded invalid ones to ensure that the feasibility and validity of the data obtained from the survey were not adversely affected.

A total of 700 copies of this questionnaire were distributed following a convenience sampling method to clinical nurses simultaneously, and 692 were collected (98.86%). After excluding invalid ones, 681 (97.29%) valid questionnaires were studied. Of all the participants, 334 (49.04%) are from the department of internal medicine and 347 (50.96%) are from the department of surgery.

This study aims to test the reliability and validity of a designed questionnaire that assesses nurses’ knowledge, attitude, and practice on preventing nosocomial infections in elderly patients. To this end, Epidata 3.1 is used to input data and SPSS22.0 and AMOS 22.0 are used to analyze them. The basic findings are described through the constituent ratio. Further, the reliability and validity of the questionnaire are observed through Cronbach’s α coefficient, test–retest reliability, content validity index (CVI), EFA, correlation coefficient and CFA.¹⁹

Nursing staff’s knowledge, attitude, and practice on the prevention of the nosocomial infection in elderly patients is designed based on the principles of objectivity and completeness, and has a guiding value. The questionnaire also considers the physiological and psychological characteristics of elderly patients, focusing on the knowledge nursing personnel need to master to prevent nosocomial infections in elderly patients. Finally, 38 items are designed to cover knowledge, attitude, and practice after modifying items in processes such as 2 rounds of Delphi expert consultation and pilot study. The final version of the questionnaire is distributed to 700 clinical nurses, and 681 (97.29%) copies are collected. The questionnaire is completed within 17 min. CVI is an important indicator reflecting the extent to which a variable measures the parameters which it is intended to measure. In this study, the results of the experts’ inquiry are used as a benchmark for content validity. The expert authority coefficient is 0.91; I-CVI 0.73–1.00, and S-CVI 0.88, suggesting this study is highly scientific.

The reliability of this study is observed through Cronbach’s a coefficient and test–retest reliability, and the validity mainly through CVI and factor analysis. The Cronbach’s a coefficient of knowledge, attitude, practice, and the questionnaire surpass 0.7, indicating a good internal consistency. The retest is conducted 3 weeks later and the Cronbach’s α coefficient of the questionnaire exceeds 0.7, showing sound stability and reliability.²⁴ The higher the cumulative variance contribution rate of common factors, the greater the accuracy with which the total variance can be explained.²⁵ The variance contribution rate of the questionnaire and each dimension is between 55.455% and 78.486%, indicating that the variation of variance can be explained effectively. The factor loading of each item in each dimension exceeds 0.4 after factor analysis. The KMO and Bartlett’s test of each dimension and the questionnaire are >0.7; the correlation coefficient among dimensions and between each dimension and the questionnaire >0.3, suggesting a high degree of correlation.

CFI is applied to verify the theoretical structure of the exploratory factors. The following is what the study finds: c2/df <5, GFI>0.8, AGFI>0.9, RMSEA<0.08, NFI>0.8, and CFI>0.9. These indicators corroborate the assumption that the model will fit well.²⁶

To summarize, the designed questionnaire has good reliability and validity, and can reflect nurses’ knowledge, attitude, and practice on preventing and controlling nosocomial infections in elderly patients. Future studies can enlarge the sample size and use the questionnaire after testing its content and structure.

As the risk of nosocomial infections in elderly patients increases, higher demands are placed on nurses in the prevention and control aspects of nursing work. The implementation of these requirements is inseparable from the nurses’ knowledge of nosocomial infections. This questionnaire is constructed by following the Knowledge–Attitude–Practice (KAP) model for measurement. The layout and content of the questionnaire is reasonable and stable. For example, the filling-in time spans 14–17 min. The assessment of nursing staff’s knowledge about nosocomial infections of elderly patients can be identified without taking too much time because the options available are plain and clear. This questionnaire is a practical and convenient evaluation tool that should be accessible to hospital infection managers.