This study used a quasi-experimental, single-group pre-post design to evaluate within-participant changes in hypertension management outcomes from baseline to postintervention. The completed Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) statement checklist is provided in Multimedia Appendix 1.

Participants were recruited from the outpatient clinic of a university-affiliated teaching hospital in northern Jordan. Recruitment took place from August 1 to September 30, 2021. Potential participants were identified using the hospital’s electronic medical records system and were approached during routine clinical appointments. The researcher introduced the study, assessed eligibility, and obtained informed consent. Of the 205 patients screened, 70 (34.1%) met the inclusion criteria, of whom 40 (57.1%) agreed to participate.

Eligibility was determined through literature review and expert consultation. Participants were eligible if they had been diagnosed with primary hypertension for at least 6 months, were aged 18 to 60 years, were actively using antihypertensive medication, were free from hypertension-related complications or comorbidities, were literate in Arabic, were able to use messaging apps such as WhatsApp, and had access to a smartphone or computer with internet connectivity.

An initial power analysis using G*Power (version 3.1.9.7; Heinrich Heine University Düsseldorf) was used to guide recruitment for this formative, single-group pilot study. Assuming a medium effect size (Cohen d=0.50) informed by prior telehealth literature [23], 80% power, and a 2-sided significance level of α=.05, the analysis suggested a minimum of 34 participants. This calculation was used as a pragmatic recruitment guide rather than as evidence that the study was powered for confirmatory efficacy testing.

Data were collected at baseline and after the 8-week intervention. The validated questionnaires assessing hypertension knowledge, self-care practices, and medication adherence were administered electronically using Google Forms and completed by participants in person in a supervised clinical setting. Baseline blood pressure was measured in the outpatient clinic using a study-provided automated electronic upper-arm blood pressure monitor (Yuwell Smart Blood Pressure Monitor, model YE680A). Each participant was assigned 1 monitor for the baseline clinic measurement and subsequent home monitoring; all participants received the same model. Participants received standardized in-person training on the correct operation of the device, including appropriate resting time, body positioning, cuff placement, and arm positioning, and they were instructed to measure and record their blood pressure twice daily, in the morning and evening. Postintervention blood pressure values were calculated by averaging the twice-daily home readings recorded during the final week of the 8-week intervention.

The 8-week telehealth pilot program was designed and facilitated collaboratively by a trained community nurse and a clinical dietitian. The program comprised home blood pressure monitoring, structured educational messaging, and biweekly telephone follow-up.

Statistical analysis was conducted using SPSS for Windows (version 25.0; IBM Corp). Descriptive statistics summarized participant demographic and clinical characteristics. Data distribution was assessed using the Shapiro-Wilk test, which indicated nonnormality (P<.05). Therefore, Wilcoxon signed-rank tests were used to compare baseline and postintervention outcomes. For each paired comparison, the effect size was calculated as r=|z|/√N, where N=40. Statistical significance was set at P<.05 (2-sided). All 40 participants contributed paired baseline and postintervention data for the 5 outcomes; therefore, no participant-level outcome data were missing from these paired analyses, and no imputation was performed.

This study received ethics approval from the Ethics Committee of Jordan University of Science and Technology (approval 197/132/2020; June 25, 2020). All participants provided written informed consent before enrollment. Participants could be identified by the study team through direct WhatsApp communication and telephone follow-up; confidentiality was maintained throughout the study. Findings are reported in aggregate, with no direct personal identifiers in the tables or manuscript. No financial compensation was provided. In-person interactions followed World Health Organization guidance on COVID-19 safety measures [27].

Participant demographic and clinical characteristics are summarized in Table 1. The sample was predominantly female and married. Most participants had health insurance, reported no tobacco use, were classified as obese, had lived with hypertension for more than 5 years, used 1 antihypertensive medication, and reported home blood pressure monitoring. Participants also reported COVID-19–related difficulties with blood pressure monitoring, medication access, and medical appointments (Table 1).

This formative pilot study evaluated within-participant outcomes over an 8-week WhatsApp-based telehealth education program with remote follow-up among adults with primary hypertension in Jordan. From baseline to postintervention, participants had higher hypertension-related knowledge and self-care scores; lower medication adherence scores, indicating better adherence; and lower systolic and diastolic blood pressure. These pre-post differences are descriptive of change within the cohort and do not establish that the intervention caused the observed outcomes.

The observed patterns in knowledge and blood pressure are consistent with previous research on digital, multicomponent educational interventions in chronic disease management [19,20]. Idris et al [19] and Katz et al [14] reported that telehealth approaches integrating personalized education and digital communication can support patient comprehension and engagement. The lower postintervention blood pressure observed in this study is also consistent with evidence on home monitoring combined with remote clinical support, including among populations experiencing health disparities [14,28].

The blood pressure pattern observed in this study is consistent with a meta-analysis by Duan et al [28], which reported decreases in systolic and diastolic blood pressure among patients using home blood pressure telemonitoring. Katz et al [14] likewise found that digital interventions incorporating remote monitoring and multicomponent strategies were associated with lower blood pressure in populations experiencing health disparities. Choi et al [29] also emphasized the role of regular home blood pressure measurement in hypertension management.

The adherence and self-care patterns observed here are also consistent with previous research linking hypertension knowledge, adherence, and self-management. Alruwaili [30] reported associations between hypertension knowledge and medication adherence. Ye et al [31] reported better self-management and blood pressure control following telehealth education. Farahmand et al [32] and Matsumoto et al [33] reported favorable outcomes associated with self-care education and pharmacist-led remote follow-up, respectively.

Evidence supporting the use of digital messaging, video content, and teleconsultation is also relevant to the intervention components used in this study. Pour et al [34] and Bijani et al [35] reported favorable adherence and blood pressure–related outcomes with interactive SMS and multimedia education. Taken together, prior studies provide context for the pre-post patterns observed in this formative pilot, while the current single-group design does not permit attribution of those changes to the intervention.

Although data for this study were collected during the COVID-19 pandemic in 2021, low-cost and widely available messaging platforms remain relevant to digital health strategies. This may be particularly pertinent in low- and middle-income countries, where substantial gaps in internet use, connection quality, and affordability persist [36].

The findings have preliminary implications for the design of accessible hypertension support. A low-cost model combining messaging-based education, home blood pressure monitoring, and scheduled nurse and dietitian follow-up may be suitable for further evaluation as an adjunct to routine care in settings where dedicated digital health platforms are difficult to access. However, this uncontrolled pilot study does not establish clinical effectiveness or support replacing standard care. Future controlled implementation studies should assess clinical outcomes together with acceptability, intervention fidelity, health care workload, equity of access, and cost before broader implementation is considered.

This study has several important methodological limitations. First, the single-group, quasi-experimental pre-post design lacks a control group; therefore, the study cannot distinguish observed change from time effects, practice effects, regression to the mean, or other concurrent influences. In addition, the multicomponent intervention design precludes isolating the contribution of WhatsApp messaging from those of home blood pressure monitoring and biweekly telephone consultations. Second, the sample of 40 participants was drawn from a single center, and eligibility required Arabic literacy, digital access, and the absence of comorbidities, limiting generalizability to older adults, people with limited literacy or connectivity, and patients with multimorbidity. Third, although the same study-provided blood pressure monitor was used for each participant at baseline and during home monitoring, baseline blood pressure was obtained in the clinic, whereas postintervention blood pressure was derived from repeated home measurements averaged over the final intervention week. Differences in measurement setting and in the number of readings contributing to each assessment may therefore have influenced the observed pre-post blood pressure differences.

This formative pilot identified favorable pre-post differences in blood pressure, medication adherence, self-care behaviors, and hypertension-related knowledge among a selected group of adults with primary hypertension. The single-group design does not establish causality or clinical effectiveness. These findings support further evaluation of the multicomponent model in larger, controlled studies that use comparable blood pressure assessment procedures across time points and include more diverse patient populations. Future studies should also examine longer-term outcomes, intervention fidelity, acceptability, equity of access, implementation workload, and cost.