This cross-sectional study encompassed 120 male employees aged above 40 years working at the Dezful University of Medical Sciences in 2018.
The sample size estimate was based on 80% power for detecting a significant relationship of 0.37 with a significance level of α = 0.05 and a 10% loss to the follow-up rate. The sample size formula is:
The participants were selected using the multi-stage sampling method. In the first stage, out of eight departments of the Dezful University of Medical Sciences, four departments were selected using the random cluster sampling method. According to the registered file of the employees, 30 men aged above 40 years from each department were included using the sample random sampling method and according to a table of random numbers (n = 120). Inclusion criteria were willingness to participate in the study, completing the written informed consent form, no history of prostate cancer, benign prostatic hyperplasia with obvious clinical symptoms, and aged above 40 years. The only exclusion criterion was unwillingness to participate in the study.
The data collection tool was a researcher-made questionnaire developed based on previous studies (
26). This questionnaire consisted of four sections. The first section included questions on demographic factors (four items about age, occupation, and others) and the second section encompassed items on performance cancer screening behavior, scored using yes (score 1) and no (score 0) options.
The third section of the questionnaire (awareness questions) was scored using 1 for correct and 0 for incorrect responses and unanswered items (0 - 12).
A panel of experts from the Dezful University of Medical Sciences, including ten specialists in health education, urology, oncology, preventative medicine, and nursing, confirmed the validity of the data collection tools by determining the content validity ratio and the content validity index.
Considering the cut-off point, the content validity of the questionnaires was determined using CVI and CVR. Higher scores indicate the higher levels of knowledge about prostate cancer. The estimated reliability screening behavior of the knowledge scale was 0.75, indicating the internalization compatibility of this questionnaire.
The fourth section consisted of questions developed based on the HBM constructs (n = 32): Perceived susceptibility (3 questions), perceived barriers (11 questions), perceived severity (3 questions), and perceived self-efficacy (6 questions), and cue to action (4 questions). A 5- point Likert scale (strongly agree (5), agree (4), no idea (3), disagree (2), strongly disagree (1)) was also used to answer the questions in the fourth section.
The internal and external consistency coefficients of the questions were determined by estimating Cronbach's alpha and test-retest coefficients, respectively, for 30 individuals in two stages with a two-week interval to evaluate the reliability of the questionnaire. It should be mentioned that these individuals were not included in the study. Cronbach's alpha coefficients of perceived susceptibility, severity, barriers, benefits and self-efficacy, and cue to action were 0.71, 0.89, 0.84, 0.71, 0.82, and 0.71, respectively.
The Statistical Package for the Social Sciences (SPSS) version 19 was used to analyze the collected data. The quantitative data are described as mean, standard deviation, and frequency. Independent t-test and regression analysis were used to examine the relationship among the variables. In this study, P < 0.05 was set as the significance level.
3.1. Ethical Considerations
This study was approved by the Ethics Committee affiliated with the Dezful University of Medical Sciences (Ethics Code: IR.DUMS.REC.1395.12). In this study, the researchers were committed to the ethical issues of obtaining informed consent from the participants, respecting for voluntary participation, and informing the participants of the research objectives.