Evaluation of the holistic health care program to develop the capacity of prison public health volunteer leaders (PPHVs) in Thailand: A participatory action research

Abstract

Background

Health promotion in correctional settings faces challenges due to limited healthcare access and restricted environments. Nurses are primary healthcare providers in correctional institutions; however, evidence on nurse-led capacity-building programs for inmate health volunteers remains limited. Developing the capacity of Prison Public Health Volunteer Leaders (PPHVs) through a holistic healthcare approach can enhance their self-reliance.

Objective

This study aimed to collaboratively develop, implement, and evaluate a holistic health care program to strengthen the capacity of PPHVs at the Central Correctional Institution for Young Offenders in Pathum Thani Province, Thailand.

Methods

This study employed a Participatory Action Research (PAR) design. A total of 100 well-behaved inmates were purposively selected as PPHVs and actively engaged as co-participants throughout the PAR process. The intervention was collaboratively designed and implemented over five weeks, comprising ten participatory training sessions that addressed physical, mental, social, and environmental health dimensions. Quantitative data were collected using validated questionnaires assessing knowledge, attitudes, health practice skills, data management skills, and overall capacity at baseline, post-intervention, and at 1-month follow-up. Data were analyzed using repeated measures analysis of variance (ANOVA).

Results

The findings revealed statistically significant improvements (p <0.001) in participants’ knowledge (F = 778.41, ηp² = 0.887), attitudes (F = 889.09, ηp² = 0.900), health practice skills (F = 1241.89, ηp² = 0.917), data management skills (F = 546.81, ηp² = 0.847), and overall capacity (F = 727.48, ηp² = 0.880). These outcomes indicate substantial enhancement in PPHVs’ ability to perform health promotion and data management roles proficiently.

Conclusion

The holistic health care program significantly improved PPHVs’ capacity, suggesting promise for strengthening inmate health volunteer programs in correctional settings. These findings have significant implications for nursing practice in designing capacity-building programs, nursing education in preparing nurses for correctional care, and nursing policy in developing standards for correctional nursing in Thailand.

Trial Registry Number

Thai Clinical Trials Registry (TCTR20260115003)

Background

Health is a fundamental human right extending equally to incarcerated populations; yet prisoners remain among the most underserved groups in public health systems globally, facing limited access to preventive, promotive, and curative services due to environmental constraints, administrative barriers, and healthcare personnel shortages (Saraban, 2021; Yesuf et al., 2024). In Thailand, correctional healthcare relies on a critically limited workforce serving a large inmate population, and despite the 2015 Cabinet Resolution affirming prisoners’ rights to equitable healthcare, service disparities persist (Chramnanpho & Nakahro, 2023; Thai Department of Corrections, 2020; Thai Ministry of Public Health, 2020). Rotating nursing schedules delay treatment for non-emergency patients, and reliance on untrained Prison Public Health Volunteer Leaders (PPHVs) for preliminary screenings carries inherent risks of misdiagnosis and deferred care (Aon et al., 2025; Thai Department of Health, 2018).

Although prior studies and national initiatives, including His Majesty King Maha Vajiralongkorn’s Ratchathan Pun Suk: Doing Good with Hearts Project, have improved medical equipment access and basic health education, these efforts have been primarily supply-driven and have not systematically addressed the capacity of inmate health volunteers (Stürup-Toft et al., 2018; Thai Department of Health, 2018). Existing Thai prison health programs have focused predominantly on disease-specific campaigns (e.g., TB, HIV) or single-domain health education, without integrating knowledge, behavioral skills, leadership development, and health data management into a unified framework (Rakpaitoon et al., 2022; Sawasdipanich et al., 2018). Critically, these programs have not positioned inmates as active co-producers of health, limiting sustainability and peer-based reach (Bonato et al., 2024; Hooper et al., 2025).

To address these limitations, this study draws on three theoretically complementary frameworks. The WHO Holistic Health Care framework (Chaiyarach et al., 2025; World Health Organization [WHO], 2023) provides a content architecture that integrates physical, mental, social, and environmental dimensions to promote comprehensive well-being. Primary Health Care (PHC) principles (Behera et al., 2022) provide the operational logic, emphasizing community participation, health equity, and self-reliance, thereby justifying inmate-led health promotion as a viable and sustainable system. Participatory Action Research (PAR) provides the methodological mechanism of change: through iterative cycles of collaborative planning, action, and reflection, PAR embeds learning within practice contexts, fostering ownership, critical consciousness, and adaptive capacity among participants (Cusack et al., 2018; Duea et al., 2022; Kemmis & McTaggart, 2005; Tetui et al., 2018). These frameworks propose that capacity development among PPHVs operates through three mechanisms: knowledge acquisition, attitudinal transformation, and the application of practiced skills, each of which is reinforced by participatory reflection.

Despite growing interest in participatory prison health initiatives, a critical appraisal of the existing literature reveals an analytically demonstrable gap. Inkaew et al. (2019) showed that an empowerment-based program improved knowledge and first-aid skills among prison health volunteers, but did not address data management competencies or leadership development. Phoglad and Sang-arun (2025) evaluated health service system development in prisons but focused on operational performance rather than on volunteer capacity building. No identified study has integrated holistic health dimensions, PHC principles, and PAR methodology into a single, evaluated capacity-building intervention for PPHVs in Thai correctional settings (Inkaew et al., 2019; Rakpaitoon et al., 2022). Critically, this gap extends into nursing science: no study has developed or evaluated a nurse-informed framework that builds lay health volunteer capacity through structured health assessment, health education, and supervisory mentorship in a correctional setting, competencies central to nursing practice yet systematically absent from existing prison health programs.

This study, therefore, addresses this gap by designing, implementing, and evaluating a Holistic Health Care Program to strengthen PPHVs’ knowledge, attitudes, health practice skills, data management skills, and overall leadership capacity at the Central Correctional Institution for Young Offenders, Pathum Thani Province, Thailand, using a PAR framework that positions inmates as active participants in sustainable prison health management and contributes to nursing science by demonstrating how nurse-informed capacity-building can extend the reach of professional nursing care in resource-constrained correctional settings.

Methods

Study Design

This study employed a Participatory Action Research (PAR) design, informed by the cyclical model of Kemmis and McTaggart (2005), which conceptualizes research as an iterative process of collaborative planning, action, observation, and reflection conducted with rather than on participants. The PAR approach was selected to actively engage inmates, correctional health staff, and researchers as co-participants in a cyclical process of problem identification, collaborative planning, action, and reflection, thereby enhancing contextual relevance, participant ownership, and sustainability of the intervention. Within the PAR framework, the intervention sought to enhance PPHVs’ knowledge, attitudes, and skills related to health promotion, disease prevention, basic care, and health rehabilitation, as well as their capacity to collect, manage, and analyze health information using a paper-based prison health information management system. The holistic health care program was collaboratively designed based on the principles of Holistic Health Care (Chaiyarach et al., 2025; World Health Organization [WHO], 2023) and Primary Health Care (Behera et al., 2022), integrating physical, mental, social, and environmental dimensions to promote comprehensive well-being, self-reliance, and leadership among participants.

The action phase of the PAR process consisted of 10 structured training sessions delivered over 5 weeks, with 2 sessions per week, each lasting 6 hours. All activities were conducted within the correctional institution using participatory learning strategies, including experiential learning, practical demonstrations, group discussions, reflective sessions, and hands-on training in health data management. Participants actively applied newly acquired knowledge and skills in real prison settings throughout the intervention period, reinforcing learning through practice and reflection.

Sample/Participants

The study population comprised 4,532 male inmates housed at the Central Correctional Institution for Young Offenders in Pathum Thani Province, Thailand (Thai Department of Corrections, 2024). Using purposive sampling consistent with PAR, inmates were collaboratively selected by the research and correctional teams to ensure ethical appropriateness, feasibility, and institutional support. Although this process may introduce selection and expectancy bias, it is inherent to PAR and was necessary to safeguard participants, build institutional trust, and ensure contextual relevance. Participants were recruited across all eight prison zones, with approximately 12–13 inmates per zone, to ensure participatory representation and diverse contextual perspectives

Eligible participants were male inmates aged 20 years or older with good behavioral records, at least a primary-level education, a middle or higher custody classification, and a minimum of one year remaining on their sentence. Additional inclusion criteria included demonstrated motivation, leadership and communication potential, willingness to serve as PPHVs, and formal approval from correctional health staff. In accordance with PAR principles, participants were expected to actively engage in problem identification, participatory learning, implementation, and reflection throughout the study period. Exclusion criteria included severe physical illness, mental instability, disciplinary issues, inability to commit to full participation, or prior involvement in similar health leadership programs. Participants who developed serious illness or experienced health emergencies during the study were withdrawn to maintain safety, ethical integrity, and data quality.

The sample size in Phase 3 was determined using G*Power software by selecting the F-test for repeated measures (within-subject design), with α = 0.05 and a statistical power of 0.95. A conservative effect size of Cohen’s f = 0.1253, derived from a prior study conducted in a comparable correctional setting (Phoglad & Sang-arun, 2025), was used to ensure adequate power even for smaller-than-expected effects, yielding a required sample size of 100 participants. This conservative approach was justified due to limited prior effect size data from similar Thai correctional health volunteer programs at study design and practical feasibility in the single-institution setting, rather than relying solely on a prior effect estimate from a comparable intervention.

Interventions

The intervention used a PAR framework with phases of inquiry, action, reflection, and re-action among PPHVs, health personnel, and prison administrators, structured to ensure relevance, ownership, and sustainability of the health program.

Phase 1: Participatory Planning and Preparation

Phase 1 focused on participatory planning and preparatory activities to establish a shared understanding of health problems, service gaps, and operational constraints within the correctional institution. The research team worked collaboratively with prison administrators, nursing staff, behavioral development officers, and inmate representatives to explore prevailing health conditions, limitations of existing inmate health volunteer systems, and the feasibility of implementing inmate-led health activities. Participatory discussions, field observations, and informal consultations revealed key issues, including limited health literacy among inmates, insufficient capacity of existing health volunteers, delayed access to health services, fragmented health data recording, and unmet physical and mental health needs. These findings provided the empirical foundation for program development and ensured institutional readiness, ethical compliance, and alignment with correctional regulations.

Phase 2: Collaborative Planning and Co-Design of the Intervention

Researchers, correctional health staff, and selected PPHVs collaboratively planned and co-designed the Holistic Health Care Program for PPHVs. The program was grounded in the principles of Holistic Health Care (Chaiyarach et al., 2025; World Health Organization [WHO], 2023) and Primary Health Care (PHC) (Behera et al., 2022), integrating physical, mental, social, and environmental dimensions of health to promote comprehensive well-being and self-reliance. Participatory planning meetings were conducted to jointly define program objectives, learning outcomes, training structure, intervention content, and evaluation strategies. Training manuals, handbooks, assessment tools, and a paper-based Health Information Management System were developed and refined to ensure feasibility in a non-digital prison environment. Orientation sessions with correctional staff and participants clarified roles, ethical safeguards, safety protocols, and expectations for ongoing participation in the PAR process.

Phase 3: Action and Implementation (Participatory Intervention)

The action phase consisted of a 5-week participatory intervention delivered through 10 structured training sessions (2 sessions per week, 6 hours per session) at the Central Correctional Institution for Young Offenders. Learning activities emphasized participatory and experiential approaches, including group discussion, demonstration, hands-on practice, case analysis, role-playing, and reflective dialogue.

The intervention comprised 10 core activities, aligned with the holistic health framework: (1) Health promotion and environmental hygiene, including nutrition, oral health, physical activity, food and water sanitation, and environmental hygiene within prison zones. (2) Surveillance, prevention, and control of communicable diseases and major health threats, focusing on tuberculosis, respiratory infections, skin diseases, and health risk awareness. (3) Emergency first aid and basic life support, including CPR, AED use, choking management, and emergency response within correctional constraints. (4) Basic health care for dependent groups, such as bedridden inmates, older adults, and inmates with disabilities, including rehabilitation and basic physical therapy. (5) Health care in the new-normal context, emphasizing infection prevention and adaptive health behaviors.

Additionally, (6) Rational drug use, herbal medicine, and Thai traditional medicine, covering medication safety, adverse drug reactions, and basic knowledge of herbal and Thai traditional practices consistent with prison health policies. (7) Health data collection and management, training PPHVs to systematically record, organize, and analyze inmate health data using a paper-based system while maintaining confidentiality. (8) Mental health and substance-use care, including mental health screening, stress management, psychosocial support, suicide risk awareness, and response to psychiatric emergencies. (9) Health communication and learning activity facilitation, focusing on peer education, health campaign planning, and behavior-change communication. (10) Environmental management and sanitation in correctional settings, addressing waste management, wastewater, pest control, air quality, noise, lighting, and accident prevention. The details of the program to develop the capacity of prison PPHVs are presented in Table 1, based on the 4-dimensions.

Table 1.

Intervention matrix of the holistic health care program for prison PPHVs in Phase 3: Action and implementation

Session//Week	Core Activity	Holistic Dimension	Key Content/Activity Details	Learning Methods
Session 1/Week 1	Health Promotion & Personal Hygiene	Physical/Social	Concepts of health promotion; balanced nutrition in prison; oral health care; physical activity in confined settings; food and water safety; personal hygiene practices; role of PPHVs in promoting daily healthy behaviors within prison zones.	Interactive lecture, group discussion, demonstration, hands-on practice
Session 2/Week 1	Disease Surveillance, Prevention & Control	Physical/Environmental	Common communicable diseases in prisons (TB, respiratory and skin infections); disease transmission routes; symptom screening; basic surveillance; prevention measures; referral procedures; health risk awareness.	Case-based learning, role play, group discussion
Session 3/Week 2	Emergency First Aid & Basic Life Support	Physical	Basic first aid principles; wound care; bleeding control; choking management; cardiopulmonary resuscitation (CPR); emergency response adapted to correctional constraints; coordination with prison health staff	Demonstration, simulation, hands-on skills training
Session 4/Week 2	Care for Dependent and Vulnerable Groups	Physical/Social	Care for older inmates, bedridden inmates, inmates with disabilities or chronic illnesses; basic rehabilitation; mobility assistance; prevention of complications; ethical considerations in inmate care.	Demonstration, guided practice, small-group activities
Session 5/Week 3	Health Care in the New-Normal Context	Physical/Environmental	Infection prevention and control; adaptive health behaviors; outbreak preparedness; personal protective practices; maintaining health services during public health emergencies.	Scenario-based discussion, problem-solving exercises
Session 6/Week 3	Rational Drug Use & Traditional Health Practices	Physical	Principles of rational drug use; medication safety; adverse drug reactions; basic knowledge of herbal medicine and Thai traditional practices consistent with prison health policies.	Demonstration, guided discussion, practice-based learning
Session 7/Week 4	Health Data Collection & Management	Physical/Mental	Use of paper-based health record system; data recording formats; confidentiality and ethics; data organization; basic data analysis for health planning; reporting to health staff.	Hands-on practice, supervised exercises
Session 8/Week 4	Mental Health & Substance Use Care	Mental/Social	Mental health promotion; stress management; emotional regulation; peer support; substance use awareness; suicide risk signs; response to mental health emergencies	Role play, case discussion, reflective dialogue
Session 9/Week 5	Health Communication & Peer Learning Activities	Social	Health communication skills; peer education techniques; facilitating group learning; health campaign planning; ethical leadership and empathy	Group work, simulation, participatory presentation
Session 10/Week 5	Environmental Health & Sanitation Management	Environmental/Physical	Waste and wastewater management; pest control; air quality; lighting and noise; accident prevention; environmental risk assessment within prison zones	Field practice, observation, group discussion

Phase 4: Reflection, Evaluation, and Re-Action

Phase 4 emphasized collective reflection, evaluation, and re-action to consolidate learning and promote sustainability. Quantitative evaluations were conducted at baseline, immediately post-intervention, and at 1-month follow-up to assess knowledge, attitudes, practice skills, health data management competencies, and leadership capacity. During monitoring visits, two specific issues were identified: (1) inconsistent completion of health data recording templates, particularly in zones with higher inmate-to-PPHV ratios, and (2) limited peer engagement during health promotion activities, reflecting low confidence among newly trained PPHVs. In response, the research team revised the data templates to simplify data-recording procedures, provided targeted supplementary materials to address documentation skills, and restructured peer-support sessions to pair experienced PPHVs with newer members. Ongoing coordination with nursing and behavioral development staff reinforced these adjustments. A final workshop presented findings to administrators, health staff, and PPHVs, then led an open policy dialogue to develop recommendations for institutional integration. Program manuals, revised data templates, and operational guidelines were handed over to the prison health unit, ensuring the intervention served as an ongoing capacity-building and system-strengthening mechanism.

Randomization

Random allocation was not undertaken because this study employed a PAR design with a single intervention group focused on collaborative program development rather than outcome comparison. All eligible participants were purposively assigned to the intervention and enrolled by the principal investigator in collaboration with correctional staff. Blinding was not feasible due to the study’s participatory nature. However, research assistants not involved in the intervention conducted all data collection and analysis independently. Although blinding to assessment time points (baseline, post-intervention, and follow-up) was not feasible given the sequential study design, interviewer bias was minimized through structured two-day pre-study training covering standardized question delivery, neutral probing, and data recording, supported by a written protocol manual and pre-study inter-rater reliability checks.

Instruments

The study employed six instruments developed by the researchers based on the Health Promotion Theory (Behera et al., 2022; World Health Organization [WHO], 2023) and an extensive review of related literature and empirical studies (Chaiyarach et al., 2025; Rungreangkulkij et al., 2021; Wilma et al., 2023). The instruments were designed to assess the holistic capacity of PPHVs to community-based health work within a correctional environment. All tools were structured as interviews or questionnaires and were developed specifically to suit the literacy levels and contextual constraints of incarcerated participants.

Part 1: General Information Questionnaire. This section consisted of 16 structured items that gathered demographic and background information, including age, education level, marital status before incarceration, duration of imprisonment, remaining sentence term, and health conditions. Additional items explored participants’ health experiences and leadership roles as PPHVs, such as participation in health activities, recruitment motivation, prior experience, work preferences, collaboration with staff and peers, and perceived expectations and interest in health volunteerism. Both closed- and open-ended questions were used. The Index of Item-Objective Congruence (IOC) for this instrument was 0.96.

Part 2: Knowledge of Community Health Operations Scale. This instrument contained 40 dichotomous (true/false) items measuring participants’ knowledge of public health concepts, preventive care, and community health operations. Each correct response received 1 point; incorrect responses received zero. Scores were interpreted according to Bloom’s criteria (Bloom, 1971) as high (>80%, 32–40), moderate (60–79%, 24–31), or low (<60%, 0–23). The IOC was 0.96, and reliability testing using the Kuder-Richardson 20 (KR-20) formula yielded a coefficient of 0.86, indicating high internal consistency.

Part 3: Attitude toward Community Health Operations Scale. Developed using a 5-point Likert scale (1 = strongly disagree to 5 = strongly agree), this 20-item instrument measured positive attitudes toward community health work. Items included both positive and negative statements and were scored directly or reverse-scored as appropriate. Scores were categorized following Best’s criteria (Best, 1977): high (3.67–5.00), moderate (2.34–3.66), and low (1.00–2.33). The IOC was 0.92, and Cronbach’s alpha coefficient was 0.91.

Part 4: Public Health Practice Skills Assessment. This 30-item, 3-point rating scale (3 = regular practice, 2 = occasional, 1 = never) assessed participants’ frequency and proficiency in public health practices, including health education, disease surveillance, hygiene maintenance, and first aid. Both positively and negatively worded items were included. The interpretation followed Best’s interval criteria (Best, 1977): good (2.34–3.00), moderate (1.67–2.33), and low (1.00–1.66). The IOC was 0.89, and reliability testing yielded Cronbach’s alpha = 0.92.

Part 5: Health Data Management Skills Assessment. This 10-item, 3-point scale assessed participants’ ability to record, organize, and analyze health information within a paper-based prison health database. Skills included health record maintenance, data categorization, and confidentiality awareness. Scoring followed the same 3-point structure (Best, 1977) as above, with interpretation as good (2.34–3.00), moderate (1.67–2.33), and low (1.00–1.66). The IOC was 0.90, and reliability (Cronbach’s alpha) was 0.95, reflecting excellent internal consistency.

Part 6: PPHV Capacity Evaluation Form. This 15-item tool evaluated overall leadership and competency of PPHVs in implementing health programs, facilitating peer education, and coordinating with correctional staff. It also used a 3-point rating scale (3 = regularly, 2 = occasionally, 1 = never) and the same interpretive ranges as above (Best, 1977). The IOC was 0.91, and reliability testing indicated a Cronbach’s alpha of 0.92, confirming high reliability.

All instruments underwent expert review by a panel of 5 specialists in public health, behavioral science, and correctional healthcare to assess clarity, relevance, and cultural appropriateness. The IOC values across all 6 parts ranged from 0.89 to 0.96, exceeding the acceptable threshold (>0.50). Additionally, face validity was established through a systematic review involving both subject-matter experts and representatives of the target population. A panel of five experts in public health, behavioral science, registered nursing, correctional health, and health promotion examined the draft instruments, assessing each item for clarity of wording, relevance to study objectives, and suitability for use among incarcerated participants. Following preliminary revisions based on expert feedback, the refined instruments were pilot-tested with a small group of participants who shared characteristics similar to those of the study population and completed the questionnaires via interviewer-assisted administration. Feedback on item comprehensibility, cultural appropriateness, and ease of response was gathered through informal probing and follow-up discussions. Input from both experts and pilot participants informed minor modifications, including simplifying language, clarifying instructions, and refining item phrasing to better reflect the study context.

A pilot study with 30 inmates who shared characteristics similar to those of the main participants but were not included in the main study was conducted to assess comprehension and reliability prior to the main data collection. The reliability analysis demonstrated satisfactory internal consistency across all instruments. The knowledge of community health work scale showed good reliability with a Kuder-Richardson 20 (KR-20) value of 0.86, while the remaining instruments in Parts 3 to 6 demonstrated excellent reliability, with Cronbach’s alpha coefficients ranging from 0.91 to 0.95. All coefficients exceeded the acceptable threshold of 0.70, indicating that the instruments were reliable and suitable for use in this study. All instruments for health practice skills and overall capacity were administered by trained interviewers rather than completed independently by participants, reducing self-perception bias in these assessments.

Data Collection

Data were collected at baseline, post-intervention, and 1-month follow-up using validated questionnaires and structured interview tools to assess demographic characteristics, health behaviors, knowledge, attitudes, public health practice skills, health data management competencies, and leadership capacity of PPHVs. Face-to-face interviews were conducted by trained interviewers independent of correctional facility staff in private rooms within the institution, with no correctional officers present, to minimize the influence of authority, social desirability bias, and institutional compliance effects. Participants were informed of the voluntary and confidential nature of their participation before data collection. This approach accommodated varying literacy levels while maintaining data integrity. Data collection occurred from October to December 2025 at the Central Correctional Institution for Young Offenders in Pathum Thani, Thailand.

Data Analysis

Data analysis was conducted using IBM SPSS ver. 29.0.1 (IBM Corp.), with a significance level set at 0.05. Descriptive statistics, including frequencies, percentages, means, and standard deviations (SDs), were used to summarize participants’ demographic characteristics and baseline data. Normality of continuous variables was assessed using the Kolmogorov–Smirnov test, confirming that all dependent variables were normally distributed (all p > 0.05). Repeated-measures ANOVA was employed to evaluate within-subject differences across three measurement points (baseline, post-intervention, and 1-month follow-up) and assess sustained intervention effects. Sphericity was evaluated using Mauchly’s test; the assumption of sphericity was satisfied for all outcome variables (all p >0.05), and standard Sphericity Assumed F-statistics are reported. Effect sizes are reported as partial eta-squared (ηp²). Post hoc comparisons were performed using a Bonferroni correction, with i-values adjusted for multiple comparisons to control for family-wise error.

Ethical Considerations

This study was approved by the Valaya Alongkorn Rajabhat University under the Royal Patronage Research Ethics Committee (IRB No. 0053/2025; COA No. 0090/2025) on September 24, 2025, and conducted in accordance with the Declaration of Helsinki. Recognizing prisoners as a vulnerable population, the research prioritized safeguarding their rights, dignity, and privacy. Participation was voluntary, with written informed consent obtained after a clear explanation of the study’s purpose and procedures. All data were anonymized to ensure confidentiality and protect human rights throughout the research process. The Thai Clinical Trials Registry number for this study was TCTR20260115003.

Bias

Selection bias was minimized through purposive sampling with clearly defined inclusion and exclusion criteria, ensuring that participants were suitable and able to engage in participatory action and reflection processes. Although participant involvement is intrinsic to PAR, this was managed through standardized procedures to maintain methodological rigor. Additionally, information bias was reduced by using validated, reliable instruments with high content validity and internal consistency. Structured interviews were used to accommodate varying literacy levels and to ensure a consistent understanding of questionnaire items. Finally, observer and measurement bias were minimized through standardized data-collection protocols, interviewer training, and consistent instruments across all measurement points. In addition, independent research assistants not involved in program implementation supported data handling and verification.

Results

Participant Flow and Characteristics

A total of 132 male inmates from the Central Correctional Institution for Young Offenders in Pathum Thani Province were initially screened for eligibility to participate in the study. Of these, 32 individuals were excluded for not meeting the inclusion criteria (n = 15), health-related limitations that prevented full participation (n = 9), or declining to participate (n = 8). Consequently, 100 eligible participants were enrolled in the study and participated in the Holistic Health Care Capacity Development Program for PPHVs. All participants completed the baseline, post-intervention, and 1-month follow-up assessments. Zero attrition is attributable to several contextual factors inherent to this study: the supervised and controlled nature of the correctional setting, purposive selection of participants with demonstrated motivation and stable custody status, and active institutional facilitation by correctional health officers and behavioral development staff throughout all phases of the PAR process. No missing data were present across all measurement points; therefore, no imputation or missing data procedures were required.

Baseline Data

At baseline, all 100 participants were male inmates with a mean age of 31.4 years (SD = 9.2); half were aged 20–29 years, reflecting a young and active group suitable for leadership development. Most had at least a secondary education (83.0%), and 14.0% held a bachelor’s degree. Over half were single (52.0%), and 66.0% had been incarcerated for 1–5 years, with 78.0% having at least 1 year remaining before release, allowing sustained program participation. In terms of health, 83.0% reported no chronic diseases, while 17.0% had conditions such as hypertension, hyperlipidemia, or diabetes, highlighting the need for NCD prevention. Nearly half (48.0%) had prior experience in health-related activities, and most (76.0%) were nominated by prison staff, while 24% joined voluntarily. All were first-time volunteer leaders with no prior training (100.0%). Regarding skills, most were confident in basic patient care (65.0%), health communication (20.0%), and data recording (15.0%). Over half (55.0%) participated in health activities every week, and 92.0% received support from staff or peers. Motivation was high, with 66.0% expecting to gain health knowledge and 77.0% expressing strong interest in public health volunteer work, indicating readiness for capacity building under the holistic healthcare program.

Health Behaviors

Overall, the 100 PPHVs demonstrated favorable health behaviors across physical and mental dimensions. Nearly half (46.0%) slept 7–8 hours per night, while 34.0% slept more than 8 hours, indicating adequate rest. All participants (100.0%) ate 3 meals daily, and 79.0% drank 6–8 glasses of water per day. Regular physical activity was common, with 43.0% exercising daily and 37.0% 3 to 4 times weekly. Risk behaviors were minimal; although 89.0% had a history of smoking, all had quit, and 11.0% had never smoked. Before incarceration, 45.0% reported occasional substance use and 20.0% frequent use, emphasizing the need for continued rehabilitation support. Regarding mental health, 46.0% reported never feeling stressed, while 41.0% experienced occasional stress. Most (70.0%) managed stress effectively through exercise or engaging activities. Emotional control was moderate to high among 91.0% of participants, indicating good psychological resilience and adaptability within the correctional environment.

Effects of the Holistic Health Care Program on PPHVs’ Capacity

Repeated Measures ANOVA revealed statistically significant improvements across all five outcome domains at baseline, post-intervention, and 1-month follow-up (all p < 0.001), with large-to-very-large effect sizes, indicating both immediate and sustained gains (Table 2 and Table 3).

Table 2.

Descriptive statistics and repeated measures ANOVA of outcome variables within groups (n = 100)

Outcome Variables	Baseline Mean (SD)	Post-Intervention Mean (SD)	1-Month Follow-Up Mean (SD)	SS	df	MS	F	p
Knowledge of Community Health Operations (ηp2 = 0.887)
Time	11.25 (5.15)	29.96 (5.14)	36.81 (4.13)	35010.00	2	17505.00	778.41	<0.001*
Error (Within-group-error)				4452.66	198	22.49
Attitude Toward Community Health Operations (ηp2 = 0.900)
Time	47.07 (10.04)	76.27 (7.48)	92.43 (5.20)	105710.51	2	52855.25	889.09	<0.001*
Error (Within-group-error)				11770.83	198	59.45
Health Practice Skills in Community Health Operations (ηp2 = 0.917)
Time	42.83 (8.67)	70.67 (7.05)	84.69 (5.81)	100240.45	2	50120.22	1241.89	<0.001*
Error (Within-group-error)				7990.89	198	40.36
Health Data Collection and Analysis (ηp2 = 0.847)
Time	14.03 (3.47)	21.83 (2.40)	26.53 (1.87)	11934.407	2	5967.20	546.81	<0.001*
Error (Within-group-error)				2158.93	198	10.90
Overall Capacity of PPHVs (ηp2 = 0.880)
Time	22.36 (5.07)	34.73 (4.20)	42.73 (3.34)	29810.54	2	14905.27	727.48	<0.001*
Error (Within-group-error)				4056.793	198	20.49

Note. PPHVs = Prison Public Health Volunteer Leaders; ANOVA = analysis of variance; SS = sum of squares; df = degrees of freedom; MS = mean square. Mean (SD) values appear on the Time row only; Error rows reflect within-group error and carry no descriptive values.

^*Statistically significant at p <0.05

Table 3.

Post-hoc pairwise comparison with Bonferroni correction of outcome variables at 3 time points (n = 100)

Variables	Time		Mean difference	SE	p
Knowledge of Community Health	Baseline	Post-intervention	-18.71	0.718	<0.001*
	Baseline	1-month follow-up	-25.56	0.647	<0.001*
	Post-intervention	1-month follow-up	-6.85	0.644	<0.001*
Attitude Toward Community Health	Baseline	Post-intervention	-29.20	1.242	<0.001*
	Baseline	1-month follow-up	-45.36	1.023	<0.001*
	Post-intervention	1-month follow-up	-16.16	0.989	<0.001*
Health Practice Skills in Community	Baseline	Post-intervention	-27.84	0.989	<0.001*
	Baseline	1-month follow-up	-41.86	0.873	<0.001*
	Post-intervention	1-month follow-up	-14.02	0.825	<0.001*
Health Data Collection and Analysis	Baseline	Post-intervention	-7.80	0.460	<0.001*
	Baseline	1-month follow-up	-12.50	0.468	<0.001*
	Post-intervention	1-month follow-up	-4.70	0.472	<0.001*
Capacity of Prison Public Health Volunteer Leaders	Baseline	Post-intervention	-12.37	0.646	<0.001*
	Baseline	1-month follow-up	-20.37	0.590	<0.001*
	Post-intervention	1-month follow-up	-8.00	0.681	<0.001*

Note. PPHVs, Prison Public Health Volunteer Leaders; SE, standard error.

^*Statistically significant at p <0.05, Bonferroni-adjusted for multiple comparisons.

Knowledge scores improved from baseline (mean ± SD, 11.25 ± 5.15) to post-intervention (29.96 ± 5.14) and 1-month follow-up (36.81 ± 4.13) (F_(2,198) = 778.41, ηp² = 0.887). Attitude scores increased from 47.07 ± 10.04 to 76.27 ± 7.48 and 92.43 ± 5.20 (F_(2,198) = 889.09, ηp² = 0.900). Health practice skills rose from 42.83 ± 8.67 to 70.67 ± 7.05 and 84.69 ± 5.81 (F_(2,198) = 1241.89, ηp² = 0.917). Health data management skills improved from 14.03 ± 3.47 to 21.83 ± 2.40 and 26.53 ± 1.87 (F_(2,198) = 546.81, ηp² = 0.847). Overall capacity scores increased from 22.36 ± 5.07 to 34.73 ± 4.20 and 42.73 ± 3.34 (F_(2,198) = 727.48, ηp² = 0.880).

Bonferroni-adjusted pairwise comparisons confirmed significant differences across all time points and domains (all p < 0.001), with continued improvement from post-intervention to 1-month follow-up, indicating sustained rather than merely immediate effects (Table 3).

Clinical Significance of Capacity Development

Collectively, the improvements across all five outcome domains suggest clinically meaningful capacity development among PPHVs. Knowledge improved from a limited to a more proficient understanding of community health operations. Attitudes showed a positive shift toward health-promoting values. Health practice skills were developed to a level considered adequate for peer health education, disease surveillance, basic first aid, and preventive care. Health data management skills improved sufficiently to support systematic health record keeping within the correctional setting. Overall leadership capacity reached a level consistent with functioning as inmate health volunteer leaders. These gains have potential implications for the delivery of inmate health services within the institution.

Participatory Reflection and Learning Outcomes (Phase 4: Reflection)

Following completion of the participatory intervention, structured reflection sessions were conducted with PPHVs, correctional health officers, and behavioral development staff to review experiences gained during program implementation. Participants reported increased confidence in performing health-related roles, a clearer understanding of their responsibilities as peer PPHVs, and improved communication with fellow inmates and prison staff. Key reflections highlighted that hands-on practice and real-world application within prison zones enhanced learning retention and problem-solving abilities. PPHVs emphasized that participatory learning methods fostered mutual support, teamwork, and a sense of ownership over health activities. Challenges identified during implementation, such as time constraints and coordination across prison zones, were openly discussed and addressed through collective problem-solving.

Re-Action and Adaptation of Health Practices

Insights gained from participatory reflection informed a re-action phase, during which PPHVs adjusted their health activities to better align with contextual needs. Modifications included improving health communication strategies, reorganizing task distribution among PPHVs within prison zones, and enhancing coordination with prison health officers for referral and follow-up. Participants reported greater efficiency in conducting peer health education, health screening, and basic support activities. The re-action process showed PPHVs used reflective learning to refine practices independently, supporting the intervention’s sustainability beyond formal training.

Discussion

The findings suggest that the holistic health care program was associated with substantial improvements in PPHVs’ knowledge, attitudes, practices, data management skills, and overall leadership capacity. Improvements were statistically significant across all variables (p < 0.001), with large effect sizes and retained outcomes at 1-month follow-up, although the absence of a control group limits causal inference. These results highlight the potential of a holistic, participatory, and context-sensitive training model for health capacity building in correctional settings characterized by structural and resource constraints.

Beyond the observed quantitative improvements, this study demonstrates the value of applying a PAR approach as a structured mechanism for capacity building in correctional health settings. Unlike conventional single-group intervention studies, PAR emphasizes active participation, shared decision-making, and iterative learning throughout the research process. By engaging PPHVs as co-participants rather than passive recipients, the intervention fostered ownership, responsibility, and contextual adaptation of health practices. The large effect sizes observed across all outcome domains may partly reflect this participatory orientation, though design limitations preclude definitive attribution. PAR enhances contextual relevance and ecological validity by embedding learning, practice, and reflection within real-world settings, though it does not substitute for experimental controls (Cusack et al., 2018; Duea et al., 2022; Tetui et al., 2018).

Knowledge improvement was the most pronounced outcome, reflecting the value of experiential and participatory learning approaches. Through scenario-based training, real data recording exercises, and group reflection, participants not only acquired factual health knowledge but also internalized its application in daily prison health work. The findings align with Inkaew et al. (2019), which showed that an empowerment-based program significantly improved knowledge, perceived empowerment, and practical skills in first aid and basic disease screening among prison health volunteers, supporting the utility of participatory capacity-building interventions in correctional settings. Moreover, this aligns with Kolb’s experiential learning theory, which emphasizes learning through active engagement and reflection, and corroborates prior studies showing that participatory training significantly enhances health literacy and practical understanding among community volunteers (Wijnen-Meijer et al., 2022).

In terms of attitude development, participants showed notable improvements in positive perceptions toward health promotion and volunteer service following the intervention. Activities emphasizing mindfulness, peer dialogue, and self-reflection fostered intrinsic motivation, empathy, and a sense of purpose, factors central to sustainable behavioral change. These results echo the Theory of Planned Behavior (Ajzen, 1991), suggesting that knowledge and perceived competence directly influence attitudes and motivation. The inclusion of mental and spiritual well-being sessions also contributed to emotional regulation and self-efficacy. The findings are consistent with the study by Inkaew et al. (2019), which showed that the intervention program significantly improved perceived empowerment among prison health volunteers. This finding is also consistent with Saksaen and Insook (2026), who found associations between positive attitudes toward health promotion and greater engagement in health-related activities among prison health volunteers.

Health practice and operational performance among PPHVs improved significantly following the intervention. By engaging participants in health screening, health education, and small-group leadership exercises, the program strengthened both technical and interpersonal competencies. The emphasis on teamwork, communication, and problem-solving fostered an integrated understanding of health operations (Kumtanat & Rungreangkulkij, 2026a). Structured reflection sessions within the PAR cycle enabled PPHVs to evaluate their performance, identify operational challenges, and collaboratively refine health practices within prison zones. These reflective processes strengthened confidence, communication, and problem-solving skills, allowing participants to adjust health education strategies, improve task coordination, and enhance collaboration with correctional health staff. Such iterative learning processes are central to PAR and help explain the sustained improvements observed at the 1-month follow-up.

The findings on health practices and operational performance were consistent with those of Wilma et al. (2023), who observed that participatory, hands-on programs in correctional facilities enhanced inmates’ capacity to manage peer health initiatives. Additionally, the findings align with Inkaew et al. (2019), who showed that an empowerment-based program significantly improved practical skills among prison health volunteers. The findings of this study are consistent with those of Phoglad and Sang-arun (2025) and Kumtanat and Rungreangkulkij (2026b), which highlighted improvements in health practice and operational performance following the development of structured prison health service systems and context-sensitive care models, supporting the value of capacity-building and system-oriented interventions in correctional settings. Moreover, the findings of this study are also in line with Sukhon (2023), who demonstrated that a comprehensive, system-based prevention and control model for TB, HIV, syphilis, and HCV in prison improved service coordination, operational performance, and continuity of care.

Participants also showed substantial gains in data collection and analytical skills following the intervention, a domain often under-addressed in resource-limited correctional settings. Training in structured, paper-based health record management, adapted to a no-internet environment, enabled participants to organize and report health information more effectively within existing institutional constraints (Chuenurah et al., 2021). This result aligns with Waithira et al. (2024), who found that participatory data management training improves the accuracy and utilization of health information in constrained environments. Moreover, the mentorship and real-time feedback provided by correctional health officers reinforced skill retention and confidence in data reporting (Reid et al., 2025; Wu et al., 2023). At the operational level, the paper-based recording approach provided a feasible and contextually appropriate tool for PPHVs to document and track health information, supporting continuity of care within the institution’s existing resource framework.

Lastly, improvements in overall leadership-related competencies among PPHVs appeared to reflect the cumulative development of knowledge, attitudes, practice skills, and data literacy addressed throughout the program. Gains in knowledge provided a cognitive foundation for informed decision-making (Arafat et al., 2024), while positive attitudinal changes strengthened intrinsic motivation, role identity, and commitment to peer health roles (Alves da Costa et al., 2022). These combined gains were associated with observable improvements in participants’ initiative, communication, and accountability in health-related activities (Canete, 2025; Woodall, 2024). The observed improvements in health practice skills appeared to support participants in applying knowledge in real-world prison contexts, and improved data management skills supported communication with health staff and continuity of care. The improvements in leadership-related competencies align with findings by Inkaew et al. (2019) and Phoglad and Sang-arun (2025), which demonstrated that empowerment-based and system-strengthening interventions enhanced volunteer capacity and operational roles within correctional health settings. The present study contributes to this evidence base by demonstrating that a multi-dimensional, context-adapted intervention can strengthen health leadership-related competencies within Thailand’s correctional system, even under structural and resource limitations, though longitudinal and controlled designs are needed to confirm durability and causality (Rauniar, 2025; Woodall, 2024).

In summary, the Holistic Health Care Program was associated with meaningful improvements across the intellectual, attitudinal, behavioral, and leadership-related dimensions of PPHVs through a low-cost and contextually appropriate model. By integrating health education, peer learning, health practice skills, and participatory reflection within a single nurse-informed framework, the program was associated with PPHVs taking more active roles in prison health activities. This PAR-informed approach advances nursing’s understanding of peer-led health promotion in correctional settings and aligns with Thailand’s broader public health reform agenda. By demonstrating that inmates trained under a nurse-informed holistic framework can sustain significant gains in knowledge, attitudes, practice skills, and data management at one-month follow-up, this study provides an evidence base for repositioning the nurse’s role from direct care provider to mentor, educator, and system facilitator, reinforcing the principle that equitable access to health development must extend to all members of society, including those deprived of liberty.

Implications for Nursing Practice

The findings of this study carry meaningful implications for nursing practice in correctional and other resource-constrained settings. Nurses are uniquely positioned to lead the design, implementation, and supervision of inmate health volunteer programs, given their competencies in health assessment, education, and care coordination. To translate this role into practice, a structured nurse-led supervision protocol for PPHVs should be developed, incorporating scheduled competency assessments, standardized performance checklists, and clearly defined referral pathways between PPHVs and nursing staff. This protocol would not only promote consistency and accountability in PPHV performance but also enable systematic monitoring of nurse-sensitive outcome indicators, such as reductions in nursing workload, improvements in referral rates, documentation accuracy, and continuity of care, thereby linking volunteer capacity to measurable improvements in the quality of nursing care delivered within correctional institutions.

At the policy and practice levels, collaboration among nursing services, the Ministry of Public Health, and the Department of Corrections is essential to institutionalizing this model within national prison health strategies. Nurses from provincial health offices should lead mentoring and supervision teams to ensure quality assurance and skill transfer, while PPHV training competencies should be formally integrated into nursing pre-service and in-service curricula to build a prepared workforce for correctional health settings. Furthermore, the participatory and holistic approach demonstrated in this program is readily adaptable to other closed or semi-closed environments, such as drug rehabilitation centers and juvenile correctional facilities, positioning nursing professionals as key drivers of correctional health innovation and reform.

Future research should explore hybrid designs combining PAR with controlled or comparative approaches, where ethically and operationally feasible, to strengthen causal interpretation while preserving participatory integrity. Longitudinal PAR studies with extended follow-up periods (e.g., 3–6 months) are recommended to assess the sustainability of behavioral and leadership outcomes. Mixed-methods PAR integrating qualitative reflection with quantitative indicators would provide deeper insight into empowerment, role identity, and system-level change.

Strengths and Limitations

This study’s key strengths lie in its context-sensitive PAR design and strong participatory engagement. Active involvement of inmates as co-participants fostered ownership, relevance, and sustainability of outcomes. The experiential 5-week training accommodated diverse educational backgrounds and promoted deep learning through action and reflection. Strong institutional collaboration enhanced program fidelity, while large effect sizes and sustained improvements underscore the intervention’s robustness. The holistic integration of physical, mental, social, and environmental dimensions further distinguishes this study as a contextually adapted, multi-dimensional PAR-based model for correctional health capacity building.

Several limitations exist. The single-group pre-post design limits causal inference, but observed improvements offer preliminary evidence. The lack of a control group reflects the ethical and operational constraints in correctional settings. Potential biases, including history effects, Hawthorne effects, selection bias, expectancy bias, and social desirability bias, may have influenced results; shared method variance could also have contributed to large effect sizes. To reduce self-report bias, interviews were private, confidential, and conducted with trained, neutral interviewers. All outcomes were self-reported; no objective system-level indicators, such as referral rates or documentation accuracy, were assessed, limiting conclusions about actual service delivery. Construct validity was not formally established beyond content and face validity; confirmatory factor analysis or criterion validity testing were outside the scope of this study. Findings from one institution may limit generalizability, though transferability to similar settings is intended. Lastly, the one-month follow-up limits understanding of long-term effects; future longitudinal studies with objective measures are needed to evaluate the durability of changes.

Conclusion

The program demonstrates promising potential for holistic, participatory learning in supporting prison health capacity, particularly in resource- and personnel-limited settings. By training inmates as health volunteers, the initiative may promote self-reliance and peer support within closed environments. These preliminary findings suggest that a PAR-informed approach could inform future correctional health program development. However, given the single-site, single-group design, reliance on self-report measures, and the absence of objective system-level outcome indicators such as referral rates, screening coverage, or documentation accuracy, generalizability and conclusions regarding actual service delivery impact remain limited.

Funding Statement

Funding This research was funded by Valaya Alongkorn Rajabhat University under the Royal Patronage and supported by the Thailand Science, Research and Innovation (TSRI) through the Fundamental Fund, fiscal year 2024 (Grant No. VRU-FF67/010).

Declaration of Conflicting Interest

No conflict of interest to declare in this study.

Author Contribution

Conceptualization and design: PT, NK, SM, SC, CP; Data acquisition: PT, NK, SM, CP, SC; Review: PT, NK, SM, CP, SC; Tool development: PT, NK, SM; SC; Formal analysis and data interpretation: PT, NK, SM; Investigation: PT, NK, SM, CP, SC; Methodology: all authors; Project administration: PT, NK; Resources: PT, SM; Supervision: PT, SC; Validation: PT; Visualization: PT; Project administration: PT; Writing–original draft: PT, NK; Writing–review & editing: PT, NK. All authors read and approved the final manuscript.

Author Biography

Phannathat Tanthanapanyakorn, Ph.D., is an Associate Professor at the Faculty of Public Health, Valaya Alongkorn Rajabhat University under the Royal Patronage, Pathum Thani, Thailand.

Sasiwimol Chanmalee, M.Sc., is a lecturer at the Faculty of Public Health, Valaya Alongkorn Rajabhat University under the Royal Patronage of Pathum Thani Province, Thailand.

Sootthikarn Mungkhunthod, M.Sc., is an Assistant Professor at the Faculty of Public Health, Valaya Alongkorn Rajabhat University under the Royal Patronage of Pathum Thani Province, Thailand.

Chaninan Praserttai, M.Sc., is an Assistant Professor at the Faculty of Public Health, Valaya Alongkorn Rajabhat University under the Royal Patronage of Pathum Thani Province, Thailand.

Nonlapan Khantikulanon, Ph.D., is an Assistant Professor at the Faculty of Public Health, Valaya Alongkorn Rajabhat University under the Royal Patronage of Pathum Thani Province, Thailand.

Data Availability

The datasets are not publicly available but are available from the corresponding author upon reasonable request.

Declaration of Use of AI in Scientific Writing

Nothing to declare.