Effectiveness of the Positive Nursing Practice Environment Promotion Programme in improving patient safety in primary health care: a study protocol for a randomised controlled clinical trial

Study design and settings

This randomised, controlled, and parallel clinical trial will be conducted with investigator and participant blinding (double-blinding). Participant recruitment took place between September and October 2024 in a group of health centres within a local health unit in northern Portugal. This protocol follows the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines^34,35 and the extension for reporting results in clinical trial protocols.³⁶ Additionally, the trial will adhere to the Consolidated Standards of Reporting Trials (CONSORT) guidelines for clinical trials.³⁷ The study has been registered on the ClinicalTrials.gov platform with the ID: NCT06762015.³⁸

Hypotheses

This study aims to test the following two main hypotheses:

• the PPAPEP improves nurses' perceptions of the safety climate in primary healthcare units; and

• the PPAPEP enhances nurses’ perceptions of their NPE in primary healthcare settings.

Study participants

The study will include all nurses working in primary healthcare units, such as family health units, primary healthcare centres, among others, who express interest in the programme, agree to participate in the study, regardless of professional category or experience or academic qualifications. Participants who give informed consent but fail to attend all six sessions will be excluded from the study.

Participant selection, recruitment, and consent

Participants will be recruited through the institution’s training centre. The training centre coordinator will send all nurses employed at the institution information about the programme, along with a link to the informed consent form, a registration form, and a declaration of interest in participating. Each participant’s declaration of interest will be coded using an algorithm provided by the research team, ensuring data anonymisation and preventing the investigator from identifying participant allocation. Study design and workflow is presented in Figure 1.

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Figure 1. Study design and workflow. PPAPEP = Positive Nursing Practice Environments Promotion Programme

Participant retention strategies

To minimise dropouts and improve participant retention, a schedule with the dates and times of each session will be sent to all participants, allowing them to choose their preferred session day and time in advance.

Sample size

Considering the study’s objective, we calculated the sample size using G*Power software (version 3.1.9.6) with a two-tailed test to compare two dependent means (Student’s t-test). The parameters used included an effect size of 0.5, a significance level (α) of 0.05, and a statistical power (1-β) of 0.80. The calculation suggests a minimum total sample size of 34 participants (17 participants per group). The allocation ratio between the groups will be 1:1. Thus, we aim to recruit at least 34 nurses working in primary healthcare units who are interested in and agree to participate in the study.

Allocation, randomisation, and blinding

Participants will be allocated into two groups (intervention and control) and stratified randomisation will be performed to ensure homogeneity between the groups (1:1). Stratification will consider participants’ self-assigned codes along with sociodemographic and professional characteristics such as sex, age, educational background, professional category, total professional experience, experience in primary health care, and the type of unit where they work. Stratified randomisation will be executed using RANDOM.ORG by an independent researcher uninvolved in the PPAPEP intervention or data analysis, because it offers true random numbers that are for many purposes better than the pseudo-random number algorithms typically used in traditional computer statistical software. Regarding the randomisation during each evaluation point, questionnaires will be completed by participants, sealed in opaque envelopes labelled with the respective evaluation moment ('EM0', 'EM1', 'EM2, or 'EM3'). After the final evaluation moment ('EM3'), the questionnaires will be selected based on the administration timeline illustrated in Figure 1. This approach enables participants to choose their preferred day and time for sessions without compromising group homogeneity or randomisation. It also minimises selection and information bias by ensuring that neither the researcher nor the participants are aware of their allocation until data collection is complete. Assessments during the intervention were conducted using self-administered questionnaires, and participants were instructed not to share session information with others.

Intervention group

The intervention group will participate in the PPAPEP, which will be delivered in-person by a trained member of the research team in a designated room within the study site. The evaluations for this group will occur at pre-intervention ('EM0'), post-intervention ('EM2'), and 3 months' post-programme ('EM3'), as shown in Figure 1.

Control intervention

For the control group, evaluations will be conducted at pre-intervention ('EM0') and before the intervention sessions ('EM1'). Although they will eventually participate in the programme, only evaluations preceding the intervention will be considered.

Outcomes evaluation

Participants will complete a sociodemographic questionnaire, and the programme’s effectiveness will be assessed using two instruments: the shortened version of the Scale for the Environments Evaluation of Professional Nursing Practice (SEE-Nursing Practice)³⁹ and Safety Attitudes Questionnaire (SAQ) — Short Form.⁴⁰

The SEE-Nursing Practice consists of 59 items across three subscales: structure (29 items); process (19 items); and outcome (11 items). Participants rate each item on a five-point Likert scale (1: never to 5: always). Higher scores indicate a more favourable NPE for care quality and professional wellbeing. Scores are interpreted as follows:<35% (unfavourable), 35–55% (moderately favourable), 55–75% (favourable), and>75% (very favourable).³⁹

The SAQ — Short Form 2006 assesses healthcare professionals' perceptions of patient safety attitudes. It has been previously validated and culturally adapted to the context in which the study will be conducted.⁴⁰ The SAQ — Short Form 2006 comprises six dimensions, addressing organisational factors, work environment factors, and team factors, with a total of 30 items. Participants respond to each item using a five-point Likert scale ('strongly disagree' to 'strongly agree'). The final score ranges from 0–100, where 0 represents the worst perception and 100 the best perception of the safety climate.⁴⁰ The timing of the outcome measures and data collection evaluation moments are detailed in Table 2, following SPIRIT guidelines and the extension for reporting trial protocol outcomes.³⁶

Data analysis

Following the CONSORT guidelines,³⁷ a flowchart outlining participants’ progression throughout the study will be created. This will include information on sample size, reasons for exclusions, and participant dropouts.

Data analysis will be performed by the research team, with preliminary steps including verification of data discrepancies, potential biases, anomalies, incomplete or missing data, as well as assessments of distribution normality, linearity, and homoscedasticity. These steps ensure compliance with prerequisites for subsequent statistical analyses.

Demographic and professional characteristics of participants will be analysed using descriptive statistics. This will involve measures of central tendency, variance metrics, frequency charts, and 95% confidence intervals for all subgroups.

The analysis will include group comparison tests appropriate for the type of variable under study. A univariate analysis will assess each variable before and after the intervention. Bivariate analyses will examine correlations between dependent and independent variables, while multivariate analyses will explore interactions and relationships among them.

Primary outcomes will focus on participants’ perceptions of the NPE and safety climate in primary healthcare settings. The Student’s t-test will be used to compare group mean values, and the paired t-test will examine changes within groups. Effect size interpretations will use Cohen’s D index, categorised as small (0.2–0.49), moderate (0.5–0.8), or large (>0.8).⁴¹

Multivariate analysis will include linear regression for dependent variables such as nurses' perceptions of the practice environment and safety climate in primary health care. If assumptions of normality, homoscedasticity, and variable independence are not met, variable transformation will be considered. After regression analysis, the adequacy of the model in representing the observed data will be evaluated, along with the possibility of changes in variable effects.⁴²

Data security and management

Questionnaires will remain anonymous, and data analysed in aggregate form and access restricted to the research team. Each participant will create a unique and confidential code to link pre- and post-intervention responses, ensuring anonymity. The research team will securely store the database with password protection, accessible only to investigators.

Test monitoring

All assessment instruments used for participant evaluation have been translated and validated for the study population. Pretest questionnaires were administered to nurses to identify and address potential errors or inaccuracies and to evaluate response times.