The study was conducted in three renal units located within one public hospital and two private hospitals in Nelson Mandela Bay, Eastern Cape province, South Africa. These facilities were purposively selected because they were the only healthcare institutions in the study area that provided peritoneal dialysis services. The inclusion of sites in the Eastern Cape province is important, as it provides contextual relevance to a region with documented healthcare disparities and varying levels of access to specialised renal care. The selected renal units offer specialised nephrology services for patients undergoing peritoneal dialysis, including patient education, routine clinical monitoring, catheter care, prevention and management of dialysis-related complications, and the treatment of peritonitis. Importantly, these units actively manage patients receiving peritoneal dialysis and therefore play a central role in the prevention and management of peritonitis. As peritonitis remains a significant complication of peritoneal dialysis, these units provided an appropriate setting for exploring related clinical practices. Including both public and private hospitals was important to ensure representation of the different healthcare sectors within the region. These sectors differ in terms of service delivery models, patient populations, resource availability, and organisational structures. Incorporating both allowed for a more comprehensive understanding of peritoneal dialysis care across contexts and strengthened the transferability and richness of the study findings.

A quantitative, quasi-experimental one-group pre-test and post-test design was employed in this study to evaluate the effectiveness of an educational intervention aimed at enhancing nurses’ knowledge regarding the prevention and management of peritonitis. Participants completed a pre-test questionnaire to assess their baseline knowledge, attended the educational intervention, and subsequently completed a post-test questionnaire to measure changes in knowledge following the intervention. This design was appropriate because it allowed the researcher to evaluate the effect of the intervention in a real-world clinical setting where random assignment to intervention and control groups was not feasible or practical. The pre-test and post-test enabled measurement of participants’ knowledge before and after the intervention, thereby determining the extent of change attributable to the educational programme. Furthermore, due to the small number of nurses working in the selected renal units, the inclusion of a separate control group was not feasible, making a one-group design approach the most suitable for this study (Gray & Grove 2019).

Because of the small population, a census sampling approach was used, including all professional nurses working in these units at the time of data collection. As the population size was limited, calculating a minimum sample size was not necessary. Instead, the study aimed to include as many participants as possible. A total of n = 37 nurses participated in the pre-test, while n = 32 nurses completed the post-test (see Figure 1).

An educational intervention includes teaching strategies, such as structured training sessions and the provision of printed and electronic educational materials. The educational intervention was a structured programme designed to equip nurses with the necessary knowledge to make informed, evidence-based decisions about preventing and managing peritonitis in renal units (Polit & Beck 2014). An educational intervention was developed based on the 2022 ISPD peritonitis guidelines, adapted to the local context, and guided by the Knowledge-to-Action framework (Graham et al. 2006). The educational intervention was reviewed by experts, including a critical care specialist and two nephrology professionals. The intervention was subsequently piloted with four professional nurses from the emergency department at Hospital 1 who had expertise in peritoneal dialysis. To minimise potential bias, these nurses were requested not to discuss the intervention with nurses working in the renal unit at Hospital 1. Table 1 outlines the educational intervention.

As indicated in Table 1, the researcher implemented the educational intervention immediately after the pre-test, using a PowerPoint presentation delivered during a one-off 20-min contact session. The session was conducted by the researcher with the aid of a projector and a laptop, enabling visual demonstrations of key concepts and interactive engagement with the participants. Thereafter, the researcher gave hard copies and emailed electronic copies of the PowerPoint presentation, the 2022 ISPD peritonitis guidelines, and the screening tool developed using sections from the guidelines to respondents. In addition, the screening tool for peritonitis prevention and management was displayed in the units to support ongoing reference and implementation in practice. Details of the researcher were available to respondents should there be any concerns or questions during or after the implementation of the study. Furthermore, the researcher conducted bi-weekly monitoring visits to renal units in Nelson Mandela Bay to assess respondents’ engagement with and adherence to interventions to prevent and manage peritonitis, in line with the 2022 ISPD peritonitis guidelines. The researcher provided ongoing support to reinforce the use of guidelines and screening tools, address challenges, and clarify educational content. All participants received the same training session, educational materials, and monitoring visits. The educational intervention was implemented over 3 months (early June 2025 to late August 2025).

Written permission was obtained from the operational and unit managers of the relevant public and private renal units. Managers (gatekeepers) were informed about the study objectives, phases, recruitment procedures, and potential benefits through meetings, followed by telephonic and email communication, and were provided with copies of the ethical and institutional approval documents. After obtaining managerial approval, the first author attended morning staff meetings and scheduled in-person training sessions to conduct recruitment. During these sessions, the same study information that had been provided to the gatekeepers was shared with prospective participants. Interested nurses were screened for eligibility, and those who met the inclusion criteria were invited to provide written informed consent. Following recruitment and enrolment, suitable times for data collection were arranged telephonically with the unit managers. Data were collected using self-administered hardcopy pre-test and post-test questionnaires, each requiring approximately 15 min to complete. The questionnaires were distributed and collected in person by the researcher during scheduled data collection sessions. To ensure confidentiality, participants were assigned unique study codes, and no names or personal identifiers were recorded on the questionnaires. Participants were requested not to discuss the questionnaire items while completing them to minimise bias. The pre-test was administered immediately before the educational intervention during a 2-week period in May 2025, while the post-test was administered over a 2-week period in September 2025, following a 2-month interval after the intervention. Both questionnaires contained the same knowledge-related items, allowing for direct comparison of participants’ knowledge before and after the intervention and enabling measurement of changes attributable to the educational programme. During Phase 1, participants completed a pre-test questionnaire designed to assess their baseline knowledge of peritonitis prevention and management. The questionnaire comprised two sections: Section A collected demographic data through nine multiple-choice items, while Section B assessed knowledge of the 2022 ISPD peritonitis guidelines using 25 items rated on a three-point Likert scale (agree, not sure, disagree). The pre-test results provided a baseline against which the effectiveness of the educational intervention could be evaluated. Both the educational intervention and the study questionnaires were developed in accordance with the 2022 ISPD peritonitis guidelines. Of the n = 37 nurses who completed the pre-test, n = 32 completed and returned the post-test questionnaire. The post-test questionnaire included the same demographic and knowledge sections as the pre-test, together with an additional Section C that evaluated participants’ perceptions of the educational intervention. Section C comprised five items measured using four-point and three-point Likert scales, as well as one open-ended question. The findings from Section C are beyond the scope of this manuscript and are therefore not reported. The questionnaires were pilot tested among four professional nurses with expertise in peritoneal dialysis from the emergency department of Hospital 1, who were not part of the study population. Participants in the pilot study were asked not to share any information with nurses in the selected renal unit included in the main study, to minimise the risk of contamination. No major amendments were required following the pilot test. The data obtained during the pilot phase were not included in the main study.

Pre-test and post-test data were entered by the first author into Microsoft Excel, with each questionnaire assigned a distinct study code. The dataset was checked, cleaned, and organised according to biographical details and knowledge-related items. Data were then analysed using Microsoft Excel. Knowledge scores were calculated by summing correct responses, with a maximum possible score of 25, and were further converted into percentage scores for ease of interpretation. Because the same participants completed both the pre-test and post-test, the data were treated as paired (dependent) data, and this was accounted for in the analysis. Descriptive statistics, including frequencies, means, medians, and standard deviations, were used to summarise participant characteristics and knowledge scores. Inferential analysis was conducted using paired-samples t-tests to assess changes in knowledge before and after the intervention. In addition, repeated-measures analysis of variance (ANOVA) was used to further examine differences across the two time points where applicable. Statistical significance was set at p < 0.05, and Cohen’s d was calculated to determine effect sizes, interpreted as small (0.2–0.5), medium (0.5–0.8), and large (≥ 0.8). Missing data were minimal and handled using listwise deletion, in which incomplete paired responses were excluded from the inferential analysis. Because of the limited sample size, multivariate analysis of demographic associations was not performed.

In this study, reliability and validity were enhanced through multiple strategies. Face validity was established through expert review by the supervisor, co-supervisor, statisticians, a critical care specialist, and nephrology professionals, who evaluated whether the questionnaire appropriately measured nurses’ knowledge of peritonitis prevention and management. Their input ensured clarity, relevance, and alignment of the items with the 2022 ISPD peritonitis guidelines. Content validity was strengthened by developing the questionnaire directly from the 2022 ISPD peritonitis guidelines, ensuring comprehensive coverage of key knowledge areas related to peritonitis prevention and management. A pilot study involving four nurses was conducted prior to the main data collection to test the clarity and feasibility of the questionnaire and educational intervention. Data obtained from the pilot study were excluded from the final analysis to prevent contamination of results.

Data reliability was further supported through careful data recording, routine verification (spot checks), and independent statistical oversight.

Ethical clearance was obtained prior to data collection from the Department Research Committee, the Faculty Postgraduate Studies Committee, and the Research Ethics Committee for Health (REC-H) at the Nelson Mandela University (Ref. 1578). Additional permissions were granted by the Eastern Cape Department of Health, Life Healthcare in the Eastern Cape, and participating renal units in Nelson Mandela Bay. Participation was voluntary, and confidentiality and anonymity were ensured by using unique study codes instead of names, with no identifying information recorded. Participants were informed of their right to withdraw at any stage without penalty. To minimise coercion, especially given that participants were employees of the study sites, recruitment and data collection were conducted independently of management, and participation had no impact on employment. Data were stored securely in password-protected files and locked cabinets, accessible only to the researcher and supervisor. The study adhered to the ethical principles of autonomy, beneficence, non-maleficence, and justice, in line with the Belmont Report.

Section A of the questionnaire collected respondents’ demographic and professional information, including gender, age, experience in peritoneal dialysis, length of service in renal units, position within the unit, type of institution, highest qualification attained, frequency of use of the 2022 ISPD peritonitis guidelines, and sources of knowledge used in the care of patients on peritoneal dialysis. The participants’ demographic characteristics are summarised in Table 2.

As outlined in Table 2, a total of 69 responses were analysed: Pre-test (n = 37) and post-test (n = 32). Most respondents were female (85.3%), aged 30–49 years (69.5%), professional nurses (94.1%), and worked almost equally in public and private sectors. Over half had prior peritoneal dialysis experience (56.5%), with the largest group having 10–19 years of renal unit experience, and most held a post-graduate diploma in nephrology nursing. Use of the 2022 ISPD peritonitis guidelines was low, with over half reporting no use and only 27.5% using them weekly or daily. Knowledge of peritoneal dialysis care was mainly obtained through in-service training, formal education, and clinical experience, while other sources were rarely used; slight increases in the use of these sources were noted post-test. Chi-square analysis showed no significant demographic differences between pre- and post-test groups (p > 0.05), indicating comparable samples.

Section B (Items B1–B25) evaluated respondents’ knowledge. Each item required a single response of Agree, Not Sure, or Disagree. Table 3 presents the results, summarising the distribution of responses across all 25 knowledge items for the pre-test, post-test, and overall samples. The knowledge responses for the pre-and post-tests are outlined in Table 4.

As shown in Table 4, participants demonstrated high levels of agreement on key peritonitis diagnosis and monitoring indicators. For example, most nurses correctly identified that cloudy effluent with pain, white blood cell count > 100/µL, and a positive culture indicates peritoneal dialysis peritonitis (B1: 86% pre-test; 94% post-test), and that inspection of the exit site is essential (B20: 100% both phases). Slight post-test improvements were observed for several indicators, including cause-specific peritonitis diagnosis per culture (B3: 27% pre-test; 41% post-test) and antifungal prophylaxis co-prescription (B15: 66% pre-test; 91% post-test, p = 0.006), highlighting a statistically significant gain in knowledge in this area. Knowledge of prevention measures improved overall, particularly regarding topical antibiotic use for exit sites (B9: 81% pre-test; 94% post-test) and emptying the abdomen during gastrointestinal (GI)/gynaecological procedures (B11: 92% pre-test; 94% post-test). Strong understanding was also evident in the management of peritonitis and its complications, including refractory peritonitis leading to peritoneal dialysis failure (B25: 94% pre-test; 97% post-test). However, uncertainty persisted in certain areas. Knowledge gaps remained regarding minimum dwell time (B2: 49% pre-test; 56% post-test), organism-specific diagnosis (B3), antibiotic routes (B22, B23), and management of hypokalaemia (B14: 44% pre-test; 56% post-test).

Knowledge scores, assessed through pre- and post-test measures, are presented in Table 3.

As outlined in Table 3, participants showed improvements across all domains of peritonitis knowledge, including definition and measurement, monitoring and reporting, prevention, and management, with mean scores increasing from pre- to post-intervention. Statistically significant gains were observed in the Definition and Measurement of Peritonitis (Pre: 41.44 → Post: 54.17; p = 0.011, Cohen’s d = 0.63, medium effect), Prevention of Peritonitis (Pre: 57.09 → Post: 66.02; p = 0.029, Cohen’s d = 0.54, medium effect), and the Overall Knowledge Score (Pre: 52.71 → Post: 59.69; p = 0.007, Cohen’s d = 0.68, medium effect).

Several limitations are reported. The study used a one-group design without a control group, limiting causal inference. The relatively small sample size and short follow-up period may have influenced the detection of changes in some knowledge domains. Methodological limitations included a brief intervention, potential recall bias due to identical pre- and post-tests, a lack of usability testing, and the absence of behavioural observation. The study assessed knowledge improvement but did not evaluate long-term retention or clinical outcomes. Future research should involve larger, multi-site samples, adopt more robust and flexible designs, extend intervention duration, include observational and outcome-based measures, and use longitudinal mixed-methods approaches to enhance generalisability and impact. Based on the results, this study recommends the development, implementation, and evaluation of structured, guideline-based educational interventions to enhance professional nurses’ knowledge of peritonitis prevention and management in renal units in Nelson Mandela Bay. Education should be grounded in internationally recognised standards such as those of the ISPD and incorporated into ongoing in-service training and continuous professional development programmes. In addition, strengthening structured training is essential to improve knowledge of key areas such as diagnosis, effluent interpretation, aseptic technique, and preventive strategies, thereby supporting consistent, evidence-based practice in peritoneal dialysis care.

This study provides empirical evidence that structured educational interventions significantly improve renal nurses’ knowledge of peritonitis, particularly in foundational domains such as its definition, measurement, and prevention. It demonstrates that guideline-based education can produce meaningful knowledge gains, with medium effect sizes, reinforcing its effectiveness in clinical practice. The findings also support existing literature indicating that nurse competence is a key determinant of patient safety, infection prevention, and peritoneal dialysis outcomes. In addition, the study highlights that nurses with lower baseline exposure to peritoneal dialysis may benefit most from targeted educational interventions, underscoring the importance of continuous professional development in renal nursing.