Assessing public trust in road traffic injuries prevention policies in Iran: a cross-sectional study | BMC Public Health

The present study is a cross-sectional study conducted in 2022 in Tabriz city. This study was conducted in Tabriz, the capital of East Azerbaijan province in the northwest of Iran. The area of ​​this city is 245 square kilometers and with a population of about 1.8 million people, it is the fourth largest city in Iran. Like other big cities in Iran, it has experienced rapid urban development in the past decades. Tabriz is the largest economic center and metropolis in northwest Iran [20].

This high concentration of socio-economic activities is an effective factor in the traffic congestion on the highways and inner streets of Tabriz. According to the traffic police of Tabriz, the number of deaths caused by traffic accidents in this city has always been high. Additionally, according to the statistics of the Forensic Medicine Organization, 16,778 people died in road accidents and 317,120 people were injured in the year 2021, of which 855 people died in the province of East Azerbaijan and the number of injured people due to driving accidents in this province has been reported 15,644 people [21].

The target population of the study consisted of drivers residing in Tabriz. The inclusion criteria were being a resident of Tabriz, having a driver’s license, and willingness to participate in the study. To achieve a statistically robust and representative sample size, the researchers employed Cochran’s formula to determine the initial required sample of 384 individuals. Recognizing the importance of bolstering statistical power and mitigating potential attrition effects inherent in cross-sectional studies, this number was subsequently doubled, bringing the final cohort size to 768 individuals.

A data collection tool was meticulously devised in the form of a researcher-made questionnaire(a supplementary file), encompassing 31 Likert-scale items distributed across 6 dimensions. The development process commenced with a judicious literature review on traffic accidents, as well as the policies and measures enacted to reduce such incidents, after establishing a definition for public trust in measures and policies aimed at reducing traffic accidents. Following the conceptual foundation’s establishment, the questionnaire’s items, dimensions, and areas of inquiry were refined, preparing the groundwork for in-depth semi-structured interviews with esteemed subject matter experts and stakeholders. The interviews, conducted at a convenient location for participants, involved 12 distinguished faculty members from Tabriz University of Medical Sciences, accomplished PhD students specialized in epidemiology and healthcare management, and domain experts keen on participating in the study. To ensure ethical compliance, explicit verbal consent was obtained from all interviewees before utilizing an audio recording device to record the interview conversations. Confidentiality and anonymity were steadfastly upheld to safeguard the integrity of the interview content. Each interview session spanned an average duration of 90 to 120 min, fostering extensive and illuminating discussions. The sampling methodology employed was purpose-based, selecting individuals capable of offering rich and pertinent insights. The iterative sampling process continued until the point of data saturation, where no new information emerged.

The criteria employed for the selection of interviewees encompassed the following parameters: (1) Occupying a role associated with the management and mitigation of traffic accidents; (2) Demonstrating substantial proficiency and erudition in the domain of traffic accidents, substantiated by publications such as books, articles, and reports concerning this subject matter; (3) Manifesting a willingness and capacity to actively partake in the study’s proceedings.

In the pursuit of analyzing the data garnered from the conducted interviews, a content analysis approach was adopted. This methodology serves as a recognized technique within the realm of qualitative data analysis, facilitating the identification, analysis, and reporting of discernible patterns or themes inherent within the textual material. This method is widely used in qualitative data analysis and allows for a detailed and systematic exploration of the data.

The initial assessment tool comprised 50 questions distributed across 8 distinct dimensions, utilizing a 5-point Likert scale for responses. Subsequently, the content validity and face validity of the devised tool were meticulously evaluated. Face validity was ascertained through a qualitative approach, involving the solicitation of feedback from a cohort of 10 experts and stakeholders who were provided access to the initial tool. Notably, the questionnaire was returned by 8 of these individuals, and their invaluable insights were harnessed to rectify any identified shortcomings. The quantification of content validity encompassed the utilization of the Content Validity Ratio (CVR) and the Content Validity Index (CVI). The calculation of CVR necessitated the appraisal of each item’s examination significance by all panel members. In tandem, the determination of CVI entailed individual evaluations by panel members, wherein they gauged each item’s simplicity, relevance, necessity, and clarity, utilizing a 4-point Likert scale. Upon meticulous assessment, the number of questions within the designed tool was prudently reduced to 44, maintaining its distribution across the 8 dimensions.(Table 1).

In the third phase, the assessment of internal reliability hinged on two distinct methodologies: internal consistency, measured through Cronbach’s alpha coefficient, and the intra-class correlation coefficient, which gauges the test’s repeatability. The endeavor to gauge the internal consistency of the questionnaire involved the application of Cronbach’s alpha, where a cohort of 30 eligible participants was thoughtfully selected over a span of two weeks. Meanwhile, the test-retest method was employed to meticulously ascertain the questionnaire’s reliability. At the end of this stage, the number of designed tool questions was reduced to 34 and its distribution was still maintained in 8 dimensions.

In the fourth phase, an exploratory factor analysis was executed to glean deeper insights. As the research instrument was custom-designed for this study, the employment of exploratory factor analysis was judicious to elucidate the inter-correlation among items. Within this analysis, the default Principal Components method was adopted. The outcomes of this exploratory factor analysis yielded four key outputs, which were aptly scrutinized. Employing Varimax rotation facilitated the extraction of questionnaire factors, aiding in the disentanglement and elucidation of the underlying factors. Finally, the number of questions was reduced to 31 questions, distributed across 6 thematic areas: Safer roads (8 questions), Safe vehicle (5 questions), Safety laws (3 questions), Safe user (6 questions), Safety technology (4 questions), Road safety Management (5questions). Respondents partaking in the study expressed their perspectives using a five-tiered response scale: strongly agree, agree, neutral, disagree, and strongly disagree. The number of respondents in this stage was 681 people who were selected based on the variables of entering the study. After the participants completed the questionnaire, a score for each question was determined. We calculated this by dividing the number of people who chose each of the 5 options based on the Likert scale for each question by the total number of respondents (681). Then, we converted the resulting ratio into a percentage to determine the score for each question across all 5 options. The suitability of the sample size was assessed using the Kaiser-Meyer-Olkin (KMO) index, while the correlation among variables was scrutinized through Bartlett’s test. An eigenvalue surpassing 1 was deemed pivotal for ascertaining factors. Comprehensive findings, along with intricate insights into the study’s methodology, validity, and reliability, will be presented in a forthcoming publication.

Explicit informed consent was conscientiously acquired from all participants involved in this study, affording them the prerogative to disengage from the study at any juncture. These participants were also provided with the unwavering assurance of confidentiality and the preservation of their anonymity concerning their provided information. Ethical approval on 03/08/2022 from the Ethics Committee of Tabriz University of Medical Sciences (IR.TBZMED.REC.1398.1030). Requested and received. All participants were informed that their participation was voluntary and that their refusal would not result in any sanctions, that they could leave the study at any time without giving a reason, that no part of their information could be traced and that all their information could be No tracking. provided will be treated as confidential.in accordance with the Declaration of Helsinki.

Descriptive statistical techniques, encompassing measures such as mean, frequency, and percentage, were employed for data analysis. Additionally, inferential methods, including Chi-square, T-test, and One-way ANOVA, were utilized. Pearson’s correlation coefficient was applied to scrutinize inter-variable associations. These statistical computations were executed through SPSS software version 16. The adopted significance level for statistical tests was 0.05, adhering to conventions prevalent in social science research.

To evaluate the relations of latent factors among each other and to have an estimation for the grade of public trust, structural equation modeling (SEM) was conducted. As well to evaluate the effects of risk factors on the total grade of public trust, linear regression was fitted using a stepwise algorithm. Both methods were performed using R 4-4-2 programming language.