Abstract
Background
Elderly patients with type 2 diabetes mellitus (T2DM) often face complex healthcare needs due to comorbidities and polypharmacy, increasing the risk of poor glycemic control and drug-related problems. Comprehensive Clinical Pharmacy Services (CPS) aim to optimize medication management and improve adherence, addressing these challenges effectively.
Methods
This prospective, single-center implementation study was conducted in the outpatient clinic of the Department of Endocrinology – Diabetes of a tertiary care hospital in Vietnam. Elderly patients aged ≥ 60 years with a diagnosis of T2DM for at least one year and an HbA1c level ≥ 8% were included. A trained clinical pharmacist provided a structured CPS intervention, including Medication Therapy Management (MTM) and collaborative goal-setting. The impact of pharmacy services was assessed through the number of Drug-Related Problems (DRPs) identified and resolved in prescriptions and patient medication use behaviors, improvements in HbA1C levels, as well as the satisfaction of both physicians and patients with the services provided by pharmacists.
Results
Among 210 patients (mean age 73.5 years; 71% male), the baseline median HbA1c was 8.6% (IQR: 8.2–9.13), with 90.5% experiencing polypharmacy. A total of 231 DRPs were identified, primarily patient-related (66.2%), including unintentional misuse (28.6%) and intentional non-adherence (14.7%). DRPs related to prescribing included inappropriate drug (21.2%) and dose selection (12.6%). Of 78 pharmacist interventions, 93.5% were fully accepted or partially accepted by physicians; 100.0% were deemed clinically significant (potential Adverse Drug Event Score - pADE ≥ 0.1). Following CPS, 22.9% of patients achieved individualized HbA1c targets (p < 0.05), while the proportion of patients with HbA1c ≥ 8.5% declined from 49.2% to 32.2%. Patient and physician satisfaction with CPS was high (95.2% and 100%, respectively), though only 46.3% of patients expressed willingness to pay for services.
Conclusion
Comprehensive CPS has a significant positive impact on quality use of medicine in elderly outpatients with T2DM. These services should be formally integrated into routine diabetes care to optimize outcomes and reduce healthcare utilization in this population.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12913-025-13600-0.
Keywords: Clinical pharmacy, Elderly, Type 2 diabetes
Background
Type 2 diabetes mellitus (T2DM) is a chronic, progressive condition with a particularly high burden among the elderly. Globally, the prevalence of T2DM increases significantly with age, with individuals aged 60 years and older accounting for a substantial proportion of diagnosed cases [1]. The management of T2DM in this population is inherently complex due to age-related physiological changes, a high prevalence of comorbidities, and an increased risk of polypharmacy [2]. These factors contribute to suboptimal glycemic control and elevate the risk of drug-related problems (DRPs), which in turn heighten the likelihood of adverse clinical outcomes, including hypoglycemia, cardiovascular events, and functional decline [3, 4].
Achieving individualized glycemic targets in elderly patients is particularly challenging. Insulin resistance, progressive β-cell dysfunction, and the frequent coexistence of cardiovascular and renal complications complicate pharmacologic management. Moreover, age-associated cognitive decline, visual impairment, and reduced manual dexterity can impair adherence and self-management capacities [5]. These challenges necessitate a comprehensive and patient-centered approach that not only focuses on clinical targets but also addresses the unique functional and psychosocial limitations faced by older adults with T2DM.
Polypharmacy is nearly ubiquitous in elderly patients with T2DM, as they are commonly prescribed multiple medications to manage hypertension, dyslipidemia, and other chronic conditions. While often clinically justified, polypharmacy is associated with a higher risk of DRPs, including drug-drug interactions, therapeutic duplications, and inappropriate prescribing [6]. These problems are not only linked to treatment failure and adverse drug events but also to increased rates of emergency visits and hospitalizations [7]. Therefore, reducing the burden of DRPs is critical to improving health outcomes and preserving quality of life in this vulnerable population.
Clinical pharmacy services (CPS) have emerged as an effective intervention to address these challenges. As a health science discipline, clinical pharmacy focuses on optimizing pharmacotherapy through direct patient care, aiming to enhance treatment effectiveness and minimize medication-related harm [8]. A growing body of evidence has demonstrated that CPS can significantly reduce adverse drug reactions (ADRs), improve medication appropriateness and adherence, and contribute to better clinical outcomes and reduced hospitalizations [9, 10]. Through medication review, patient education, and interprofessional collaboration, clinical pharmacists are uniquely positioned to identify and resolve DRPs, promote adherence, and optimize therapeutic outcomes in chronic disease management, including T2DM [11]. Evidence suggests that CPS can contribute to significant improvements in glycemic control, lipid profiles, and medication appropriateness, particularly when services are integrated into routine care [12]. Importantly, elderly patients are more susceptible to the clinical consequences of poor diabetes management; thus, targeted pharmacist-led interventions in this group can help mitigate the risk of complications and functional deterioration [11].
Despite the well-documented benefits of CPS, its implementation in the care of elderly patients with T2DM remains limited—particularly in low- and middle-income countries (LMICs), where health systems often prioritize acute over chronic care, and where resources for structured CPS are lacking [13, 14]. Additionally, the absence of standardized protocols and sustainable financing mechanisms impedes the widespread adoption of CPS in outpatient settings.
The integration of CPS aligns with the global movement toward patient-centered care, which emphasizes shared decision-making and individualized treatment planning. This approach is particularly relevant in geriatric populations, where personalized care must take into account patient preferences, functional abilities, and caregiver support [15]. CPS, when delivered as part of a multidisciplinary team, fosters collaboration between pharmacists, physicians, and patients, contributing to safer and more effective diabetes management.
This study was undertaken to evaluate the impact of CPS on elderly outpatients with T2DM, a population often underrepresented in clinical research yet burdened by complex therapeutic needs in a resource - limited setting such as Vietnam. Specifically, the study aimed to assess the effects of CPS on key outcomes including glycemic control (HbA1c), resolution of DRPs, medication adherence, and patient satisfaction. The findings are intended to inform clinical practice and healthcare policy, supporting the inclusion of clinical pharmacists in multidisciplinary diabetes care teams to optimize care for elderly patients in resource-constrained settings.
Methods
Study design
This was a prospective, single-center implementation study designed to evaluate the preliminary impact of integrating Clinical Pharmacy Services (CPS) into routine care for elderly outpatients with poorly controlled type 2 diabetes.
Participants
Elderly patients aged ≥ 60 years with a diagnosis of T2DM for at least one year attending the outpatient clinic of the Department of Endocrinology-Diabetes from September to December 2022 with HbA1c ≥ 8% and not meeting their glycemic targets that were identified by the doctors and having been prescribed at least two hyperglycemia medications. Patients were excluded from the study if they were admitted to the hospital.
As this was an implementation study in a real-world outpatient setting, no formal sample size calculation was performed. Instead, a consecutive sampling approach was employed to enroll all eligible patients who met the inclusion criteria during the study period. This strategy was intended to reflect the feasibility and applicability of clinical pharmacy services in routine practice.
Usual care visit before implementing CPS
Prior to the implementation of the clinical pharmacy service (CPS), outpatients with type 2 diabetes were evaluated, consulted, and prescribed medication solely by physicians at the outpatient clinic of the Department of Endocrinology-Diabetes, with medication subsequently dispensed at the hospital’s outpatient drug dispensing counter. Pharmacists were not involved in the prescribing process or in providing comprehensive consulting services for type 2 diabetes outpatients. Consequently, this patient group did not receive routine clinical pharmacy services, such as medication review, medication reconciliation, or patient counseling, within the hospital setting.
Clinical pharmacy services implementation
The process of clinical pharmacy services in the study are presented in Fig. 1. During the intervention period, a clinical pharmacist (0.5 full-time equivalent - FTE) implemented a standardized CPS model. The service was established following the development of standard operating procedures (SOPs), covering key activities including medication review, reconciliation, and patient counseling. Pharmacists received formal training and utilized educational materials such as patient leaflets for antihyperglycemic agents.
Fig. 1.
Process of clinical pharmacy service in the study
The CPS followed a proactive, multi-step approach. One week prior to each clinic visit of patients, pharmacists reviewed patient records—including recent test results, allergies, and prescriptions—to build a comprehensive medication profile. Subsequently, they conducted telephone interviews with the patients. During the online consultation session, potential drug-related problems (DRPs) in medication-taking behaviour were identified and addressed.
Pharmacists collaborated with physicians to individualize glycemic targets and assess the appropriateness of prescribed therapies. Identified prescribing – related DRPs were discussed with prescribers, and evidence-based recommendations were proposed (clinical pharmacy interventions - CPIs).
On the day of the clinical visit, pharmacists supported physicians through reminder messages and provided face-to-face counseling to patients, especially those on insulin, to reinforce safe and effective medication use.
After CPIs were implemented, pharmacists evaluated their acceptance by physicians. Physician acceptance was classified into three levels: accepted and implemented (the physician agreed and adjusted the prescription accordingly), accepted but not implemented (the physician agreed but made no changes), and not accepted (the physician disagreed).
Outcome measures
The impact of the Clinical Pharmacy Service (CPS) was evaluated using a combination of process and outcome indicators. Process indicators included the number of drug-related problems (DRPs) identified and the frequency of clinical pharmacist interventions, reflecting the scope of pharmacist involvement and the capacity to identify suboptimal prescribing and medication use. The acceptance rate of interventions by physicians, along with the clinical significance of these interventions (as assessed by potential adverse drug event [pADE] scores), offered commentary on the relevance and quality of pharmacist contributions.
Primary outcome indicators included the resolution of clinically significant DRPs and changes in glycemic control, measured by HbA1c levels before and after CPS implementation. Additionally, qualitative feedback from both physicians and patients was collected to assess perceptions of the CPS and its perceived value in routine care.
Data collection
Information about the patients, characteristics of DRPs, and approval status of CPIs (clinical pharmacist intervention) by physicians was collected through (i) pharmacist’s medication review/reconciliation form, (ii) pharmacist’s patient counseling form, (iii) weekly pharmacist’s summary report. The Pharmaceutical Care Network Europe (PCNE) DRP classification system was used to classify and document DRPs.
Assessment of clinical significance of DRPs
Determination of the potential and severity of harm that a patient would experience due to a DRP was based on the methodology described by Nesbit to produce a potential Adverse Drug Event (pADE) score. The pADE score is a potential and severity score for discomfort, harm, and/or clinical deterioration caused by a DRP. The assessment uses the following categories for probability and severity of harm: 0 (no harm expected by the DRP), 0.01 (very low: some harm is expected, but not clinically relevant), 0.1 (minor: some harm is expected but poorly clinically relevant), 0.4 (moderate: harm is expected, clinically relevant), or 0.6 (major: damage is expected, life-threatening). Following randomization and blinding, the identified drug-related problems (DRPs) were submitted to three independent external clinical experts— two clinical pharmacists with advanced training in pharmacotherapy and an internist—both of them had over 10 years of professional experience. Each expert independently evaluated the potential clinical relevance of each DRP by assigning a potential adverse drug event (pADE) score. Any discrepancies in scoring were resolved through a consensus meeting between the three experts.
HbA1c after implementing CPS
The HbA1c value following the CPS was measured after 3 to 6 months of the intervention. Only patients with complete follow-up HbA1c results within this timeframe were included in the analysis. Patients with missing follow-up data were excluded.
Evaluation of patients’ and physicians’ perspectives on CPS
Patient and physician perspectives on clinical pharmacy services (CPS) were assessed using structured, self-developed questionnaires (Supplementary File S1: Patient and Physician Questionnaires). These instruments were designed specifically for this study based on literature review and expert input, and have not been previously published. The content and clarity of the questionnaires were independently reviewed by two experienced clinical pharmacists, and iterative feedback was incorporated to enhance relevance and comprehensibility.
The survey was conducted in February 2023 by independent researchers, using a convenience sampling approach among patients who had completed their follow-up visits during the study period. Patients evaluated six aspects, including satisfaction with convenience, pharmacist competence, perceived impact on medication use, overall satisfaction, willingness to continue CPS, and willingness to pay for consultation services. Physicians assessed five domains: pharmacist competence, contribution of CPS, impact on prescribing, overall benefit, and future expectations. All responses were rated on a 5-point Likert scale (0–4), with scores of 3–4 indicating positive feedback.
Statistical analysis
Information on participants, medication prescriptions, and clinical pharmacist interventions was recorded in an Excel database (Microsoft Excel 2020, Microsoft Corporation, Redmond, WA, USA). Statistical analysis was performed using SPSS software (version 27, SPSS Inc., Chicago, IL, USA). Descriptive statistics included mean and standard deviation for normally distributed data, while non-normally distributed data were summarized using median and interquartile range (IQR). Frequencies and percentages were used to describe participant characteristics and drug-related problems (DRPs). The differences between two independent groups (pre-intervention and post-intervention) were analyzed using appropriate statistical tests. For continuous variables, the Paired t-test was applied if the data followed a normal distribution, whereas the Wilcoxon signed-rank test was used for non-normally distributed data. For categorical variables, McNemar’s test was employed. A p-value of less than 0.05 was considered statistically significant.
Ethics approval
Ethics approval was obtained from the Ethical Committee in Biomedical Research of Friendship Hospital, Vietnam. The study was performed in accordance with the Declaration of Helsinki. All data were anonymized prior to analysis to ensure the protection of patient privacy and confidentiality.
Results
Process indicators of CPS
The study included 210 patients (75.8% of the total number of patients who did not achieve glycemic target in the Department of Endocrinology and Diabetes); Table 1 indicates process indicators of clinical pharmacy activities.
Table 1.
Process indicators of CPS implementation
| Result of implementation | n (%) | |
|---|---|---|
| Medication review (N = 210) | ||
| Total number of prescriptions | 210 (100) | |
| Total number of prescriptions with pharmacist interventions | 70 (33.3) | |
| Patient counseling | ||
| Total number of consultations, n * | 163 | |
| Total number of patients consulted (N = 210) | 136 (64.8) | |
|
Consultation form (N = 136) |
Only online | 83 (61.0) |
| Only offline | 26 (19.1) | |
| Both | 27 (19.9) | |
| Time of 1 consultation (minutes), mean ± SD | Online | 15.0 ± 7.1 |
| Offline | 18.9 ± 6.9 | |
CPS: Clinical Pharmacy Services
SD: Standard Deviation
*: including online and offline consultations
Characteristics of patients receiving the service
Table 2 shows the characteristics of the patients in the study. Among the 210 patients who received the CPS, the majority were between 65 and 85 years old (91.9%), with a mean age of 73.5 ± 5.5 years. Male patients constituted 71.0% of the cohort. Hypertension (80.5%) and hyperlipidemia (92.4%) were the most common comorbidities, while 43.8% of patients had atherosclerosis.
Table 2.
Characteristics of patients receiving the service
| Characteristics | N = 210 (%) | |
|---|---|---|
| Age (year) | >85 | 1 (0.5) |
| 65–85 | 193 (91.9) | |
| ≤ 65 | 16 (7.6) | |
| Mean ± SD | 73.5 ± 5.5 | |
| Gender | Male | 149 (71.0) |
| Female | 61 (29.0) | |
| Common co-morbidities | Hypertension | 169 (80.5) |
| Hyperlipidemia | 194 (92.4) | |
| Atherosclerosis | 92 (43.8) | |
| HbA1c (%) | Median (IQR)* |
8.6 (8.20–9.13) |
| Number of medications per prescription * | 6.3 ± 1.7 | |
| Polypharmacy (≥ 5 medications per prescription) | 190 (90.5) | |
| Number of hyperglycemic medications per prescription* | 2.8 ± 0.8 | |
| Characteristics of antidiabetic regimens | Only oral antihyperglycemic agents | 90 (42.9) |
| Only insulin | 10 (4.8) | |
| Insulin and oral AHAs | 110 (52.3) | |
*: Median (IQR); **: Mean ± standard deviation
AHAs: Antihyperglycemic Agents, IQR: Interquartile Range, SD: Standard Deviation
The median HbA1c level was 8.6% (IQR: 8.20–9.13), indicating suboptimal glycemic control. The average number of medications per prescription was 6.3 ± 1.7, with 90.5% of patients experiencing polypharmacy (≥ 5 medications per prescription). Regarding antidiabetic regimens, 42.9% of patients used only oral antihyperglycemic agents, 4.8% used only insulin, and 52.3% were prescribed both insulin and oral agents.
Characteristics of drug-related problems identified by a clinical pharmacist
A total of 231 DRPs were identified by clinical pharmacists through the clinical pharmacy process. Among these, patient-related issues (66.2%) were the most common, with key problems including incorrect administration of drugs like insulin (28.6%), intentional non-adherence (14.7%) and incorrect timing and dosing intervals (14.7%). Drug selection problems accounted for 21.2%, all due to inappropriate choices based on guidelines. Dose-related problems (12.6%) were primarily due to underdosing (10.4%). Overall, patient behavior and inappropriate drug selection were the most critical concerns. All identified DRPs (100%) were considered to have clinical significance, with the majority rated as having moderate to high clinical relevance. (Fig. 2)
Fig. 2.
Types and Clinical Relevance of Drug-Related Problems Identified (N = 231) DRPs: Drug-Related Problems Others: not classified in PCNE (arbitrary dose use)
Of the 78 CPIs for prescribing-related DRPs, 93.5% were fully or partially accepted by physicians, indicating strong pharmacist–physician collaboration. The highest acceptance was for stopping or changing medications to avoid hypoglycemia (100%). Dose adjustments and adding drugs to meet HbA1c targets were also well accepted (over 50%). The low rejection rate (6.4%) reflects the clinical relevance and feasibility of most pharmacist recommendations. (Table 3)
Table 3.
Type, acceptance rate of clinical pharmacist interventions
| Type of Intervention | Number (%) | Acceptance Rate | ||
|---|---|---|---|---|
| Accepted and implemented n (%) |
Accepted but not implemented n (%) |
Not Accepted n (%) |
||
| Add drug to meet individualized HbA1c target level | 33 (42.3) | 17 (51.5) | 11 (33.3) | 5 (15.2) |
| Add priority drug groups | 14 (17.9) | 7 (50.0) | 7 (50.0) | - |
| Stop/change medication to avoid hypoglycemic ADRs | 2 (2.6) | 2 (100.0) | - | - |
| Increase dose to meet individual | 24 (30.8) | 13 (54.2) | 11 (45.8) | - |
| Reduce dose as recommended | 5 (6.4) | 3 (60.0) | 2 (40.0) | - |
| Total | 78 (100.0) | 42 (53.9) | 31 (39.7) | 5 (6.4) |
ADRs: Adverse Drug Reactions
HbA1c improvement after CPS implementation
The results demonstrate a significant improvement in glycemic control following the clinical pharmacy intervention. Specifically, the percentage of patients achieving their individual HbA1c target increased from 0% before the intervention to 22.9% after the intervention (P < 0.05). Furthermore, the proportion of patients with HbA1c levels ≥ 8.5% decreased from 49.2% to 32.2%, although this change was not statistically significant (P > 0.05). (Table 4; Fig. 3)
Table 4.
Changes in HbA1c outcomes before and after clinical pharmacy intervention
| Parameters | (n, %) N = 118 |
P
McNemar’s test |
|
|---|---|---|---|
| Before intervention | After intervention | ||
| Patient whose HbA1C ≥ 8.5% | 58 (49.2) | 38 (32.2) | > 0.05 |
| Patients achieving individualized HbA1c targets. | 0 (0) | 27 (22.9) | < 0.05 |
Fig. 3.
Changes in HbA1c levels over time among elderly outpatients with type 2 diabetes receiving clinical pharmacy services. IQR: Interquartile Range
Boxplots illustrate the distribution of HbA1c values at 3 months before implementing CPS (T0), at baseline (T1) and after the initial pharmacist intervention (T1), and at the end of the follow-up period (T2). A statistically significant increase in HbA1c was observed from T0 to T1 (median 8.2% to 8.5%, p = 0.0002), followed by a significant decrease from T1 to T2 (median 8.5% to 8.0%, p = 0.00005). These results indicate an initial worsening, followed by improved glycemic control after sustained CPS.
Patient’s and physician’s perspective
The Table 5 presents a comparative analysis of physicians’ and patients’ perspectives on clinical pharmacy services (CPS). Overall, both groups expressed high levels of satisfaction with CPS, particularly regarding the clinical pharmacist’s knowledge and skills (100% of physicians, 82.9% of patients) and the willingness to continue participating in CPS in the future (100% of physicians, 85.4% of patients). While patients and physicians acknowledged the positive impact of CPS on prescribing quality and medication use, the proportion of patients who agreed to pay consultation fees was relatively low (46.3%). These findings highlight strong support for CPS but suggest potential challenges in implementing paid consultation services.
Table 5.
Patients’s and physicians’ perspectives about clinical pharmacy services (CPS)
| Criteria | Positive response (3 and 4 in Likert’s Scale) n (%) |
|
|---|---|---|
| Physician (n = 6) | Patient (n = 41) | |
| Satisfaction with the convenience of CPS | 5 (83.3) | 35 (85.4) |
| Satisfaction with clinical pharmacist’s knowledge and skills | 6 (100) | 34 (82.9) |
| CPS has a positive impact on prescribing quality/medication use. | 6 (100) | 28 (68.3) |
| Willing to continue participating in CPS in the future | 6 (100) | 35 (85.4) |
| Willing to pay fees for consulting activities | - | 19 (46.3) |
| Satisfaction with CPS overall | 100 | 39 (95.2) |
CPS: Clinical Pharmacy Services
Discussion
To the best of our knowledge, this is the first study in Vietnam to investigate the role of clinical pharmacy services (CPS) in optimizing prescribing for elderly patients with diabetes in a hospital setting. While previous studies have reported the effectiveness of CPS in managing diabetic patients [16], there is a lack of evidence specifically addressing elderly patients with diabetes. This population was selected as the target for CPS because they are particularly vulnerable to drug-related problems (DRPs) and suboptimal prescribing due to multiple risk factors, including polypharmacy, age-related physiological changes, and comorbidities.
As highlighted in earlier research, pharmaceutical care services for individualized patients have not yet been standardized in Vietnamese hospitals [17–19]. In low- and middle-income countries like Vietnam, one of the most significant barriers to implementing CPS in hospitals is the shortage of human resources [17–19]. Efforts should focus on tailoring CPS interventions to local needs and ensuring equitable access to these services. In this study, with only 0.5 full-time equivalent (FTE) pharmacist, we developed a structured CPS process for elderly diabetic patients who did not achieve their target HbA1c levels to ensure sustainability, time efficiency, and effectiveness.
Identification and resolution of drug-related problems (DRPs)
A total of 231 drug-related problems (DRPs) were identified in the study population, with the majority classified under patient-related causes (66.2%), followed by issues in drug selection (21.2%) and dose selection (12.6%). Among the patient-related DRPs, the most prevalent issue was unintentional incorrect use of medication, particularly insulin (28.6%), which, although rated as minor in clinical significance in all cases, may indicate a widespread gap in patient understanding or education regarding proper administration techniques. This finding is consistent with prior studies that have reported insulin administration errors to be highly prevalent among elderly patients with diabetes [20, 21], often due to visual impairment, reduced dexterity, or limited caregiver support [22, 23].
Another noteworthy patient-related problem was intentional non-adherence, observed in 14.7% of cases, where patients either took less than the prescribed dose or omitted doses altogether. While most cases were rated as minor or moderate in clinical significance, even low-severity non-adherence can contribute to long-term suboptimal glycemic control, increased risk of complications, and poor quality of life. These patterns of behavior may stem from concerns about adverse effects, medication cost, or misunderstanding of treatment necessity—factors previously documented in elderly populations with chronic conditions [24].
Inappropriate dosing also emerged as a relevant category, with 10.4% of DRPs attributed to doses being too low and 2.2% to excessively high doses of single active ingredients. Although only a portion of these were classified as major in clinical significance, inappropriate dosing in elderly patients poses substantial risks due to age-related changes in pharmacokinetics and pharmacodynamics. Clinical pharmacists, through medication review and dose optimization, play a critical role in preventing these errors and ensuring safe and effective therapy [25].
The most clinically significant DRPs were related to inappropriate drug selection according to guidelines, with 39 out of 49 cases classified as moderate in significance. This highlights the ongoing need for evidence-based prescribing and interdisciplinary collaboration, particularly in elderly patients with multiple comorbidities where therapeutic complexity is high. Studies have shown that pharmacist-led medication reviews contribute significantly to the identification and correction of such prescribing discrepancies [26–29].
Among 78 interventions proposed by clinical pharmacists, more than half (53.9%) were accepted and implemented by physicians, with an additional 39.7% accepted but not implemented, suggesting a high level of concordance in clinical judgment, even if logistical or patient-related factors may have delayed action. Notably, recommendations to add drugs to meet individualized targets and increase doses accounted for a large proportion of interventions, with acceptance and implementation rates of 51.5% and 54.2%, respectively. This indicates a moderate uptake of pharmacist input in optimizing therapy, yet also reflects the complexity of managing elderly patients, in whom comorbidities and risk of adverse effects may influence prescribing decisions. Importantly, interventions aimed at preventing hypoglycemic adverse drug reactions, such as stopping or adjusting medications, had full acceptance and implementation, emphasizing physician responsiveness to safety-oriented recommendations.
Overall, the clinical significance of the identified DRPs and the high rate of acceptance of CPI underscore the importance of integrating clinical pharmacy services into outpatient diabetes care. Although many DRPs were categorized as minor, the cumulative effect of unresolved issues—especially those involving insulin use and adherence—can substantially affect patient outcomes. These findings support previous research advocating for structured pharmacist interventions, patient counseling, and medication reconciliation as essential components of chronic disease management in elderly populations [30].
Improvement in HbA1c target
A finding of this study was the improvement in glycemic control among elderly outpatients with type 2 diabetes following the implementation of CPS. Notably, the proportion of patients achieving individualized HbA1c targets increased from 0% at baseline to 22.9% after the intervention, a statistically significant improvement (p < 0.05). Although the reduction in the proportion of patients with HbA1c ≥ 8.5%—from 49.2% to 32.2%—did not reach statistical significance, this downward trend remains clinically meaningful, particularly in the context of a high-risk elderly population with complex therapeutic needs.
These findings are consistent with previous international studies demonstrating the positive impact of pharmacist-led interventions on glycemic outcomes [31–38]. A systematic review by Wubben and Vivian reported that clinical pharmacy services were associated with reductions in HbA1c ranging from 0.5% to 1.8% across various outpatient settings [1, 39]. Similarly, a meta-analysis by Bongaerts et al. confirmed that pharmacist-led diabetes care significantly improved HbA1c levels, particularly when interventions incorporated patient education, medication review, and physician collaboration [2, 40]. The observed improvements in our study are particularly notable given the advanced age and high baseline HbA1c levels of the study population, which are often associated with diminished responsiveness to standard interventions.
From a clinical perspective, these improvements are meaningful. The UK Prospective Diabetes Study (UKPDS) demonstrated that every 1% reduction in HbA1c was associated with a 37% decrease in microvascular complications and a 14% reduction in the risk of myocardial infarction [3, 41]. In older adults, who are especially vulnerable to both hyperglycemia-related complications and treatment-related harms such as hypoglycemia, achieving individualized targets—as opposed to strict glycemic control—can help optimize benefit while minimizing risk. In this context, the role of clinical pharmacists in providing tailored education, identifying drug-related problems, and supporting individualized care plans is both clinically valuable and cost-effective.
Importantly, these findings support current international guidelines, including those from the American Diabetes Association (ADA) and the International Diabetes Federation (IDF), which emphasize the importance of setting individualized HbA1c goals in older adults based on comorbidity burden, functional status, and life expectancy [5, 42]. This study demonstrates that such guideline recommendations can be effectively operationalized in low-resource settings through the integration of clinical pharmacy services into routine outpatient care.
Collaboration and interdisciplinary care
The findings from the satisfaction survey indicate a high level of acceptance and perceived value of clinical pharmacy services (CPS) among both physicians and patients. Notably, all participating physicians (100%) expressed satisfaction with the knowledge and skills of the clinical pharmacists, and unanimously agreed that CPS positively influenced prescribing quality and that they would be willing to continue participating in such services in the future. These results underscore the potential of CPS to foster collaborative prescribing practices and enhance physician confidence in pharmaceutical care integration—an essential factor for the sustainability of pharmacist-led interventions in outpatient settings. Similar findings have been reported in previous studies, where physician support was identified as a key facilitator for successful CPS implementation and interprofessional collaboration [43, 44].
Among patients, satisfaction was also remarkably high, with 95.2% expressing overall satisfaction and 85.4.% indicating willingness to continue engaging with CPS in the future. High levels of satisfaction were observed across multiple dimensions, including perceived convenience (85.4%) and pharmacist competence (82.9%). These results are consistent with international literature suggesting that patient satisfaction is strongly influenced by the quality of communication, individualized attention, and perceived improvements in medication understanding and self-management [26, 45]. Moreover, the finding that 68.3% of patients believed CPS had a positive impact on their medication use reflects not only the clinical benefits of pharmacist intervention but also its perceived relevance and credibility from the patient perspective.
However, a notable finding was that less than half of the patients (46.3%) agreed to pay for pharmacist consulting services. This suggests that while CPS is well-received in terms of quality and utility, financial acceptability may pose a barrier to broader implementation, particularly in resource-limited settings. Previous studies in similar contexts have shown that patients’ willingness to pay is influenced by factors such as health insurance coverage, perceived cost-effectiveness, and prior exposure to pharmacist-led care [46]. These insights point to the need for policy-level support, including CPS reimbursement models or integration into national health coverage schemes, to ensure long-term viability.
Overall, the high satisfaction rates from both physicians and patients provide strong justification for the continued expansion of CPS in outpatient diabetes management. In particular, these findings support the role of clinical pharmacists not only as medication experts but also as accessible healthcare providers capable of enhancing care quality, promoting patient engagement, and strengthening interdisciplinary practice.
Study limitations
While the findings of this study are promising, several limitations must be acknowledged. The single-center design and relatively small sample size may limit the generalizability of the results. Given the real-world implementation nature of this study and the lack of a comparator arm, findings should be interpreted cautiously. The number of detected drug-related problems (DRPs) and the physicians’ acceptance rate were significantly influenced by the pharmacist’s expertise, communication skills, and the physicians’ perception of clinical pharmacy services (CPS). Furthermore, the study did not assess the impact of CPS using solid clinical endpoints (e.g., mortality, morbidity) nor did it calculate the costs associated with the service (e.g., healthcare utilization) or the patients’ quality of life. Instead, process parameters, including the number of identified DRPs, the physicians’ acceptance rate, and the clinical significance of DRPs, were employed to demonstrate the benefits of CPS in this preliminary study. The patient and physician surveys also have several limitations. First, they were conducted using convenience sampling with a small number of participants (n = 41 for patients), without formal sample size calculation, which limits the generalizability of findings. Second, the use of self-reported measures introduces potential recall and response bias, particularly for subjective outcomes such as satisfaction.
Despite these limitations, the findings provide valuable evidence suggesting that CPS is likely to bring benefits to patients in Vietnam. Future studies should aim to address these limitations by including larger, multi-center cohorts and objective measures of adherence and satisfaction.
Future research should also explore the long-term sustainability of CPS, its cost-effectiveness, and its application to other chronic conditions beyond diabetes. Policymakers should prioritize the integration of CPS into healthcare systems and allocate resources to expand these services. Additionally, healthcare providers should be encouraged to embrace CPS as a valuable component of chronic disease management.
Conclusion
The implementation of comprehensive CPS was associated with improved glycemic control, resolved DRPs, enhanced medication adherence in elderly patients with T2DM. CPS for elderly patients with T2DM is a promising strategy to address the multifaceted challenges of diabetes management in this population. Through personalized interventions, enhanced patient education, and improved medication management, CPS has the potential to significantly improve clinical outcomes and quality of life for elderly patients. These findings demonstrate the feasibility and value of integrating CPS into routine outpatient diabetes care for older adults in resource-limited settings.
Supplementary Information
Below is the link to the electronic supplementary material.
Acknowledgements
The authors of this manuscript acknowledge that this study could not have been conducted without the help of the many respondents involved in the course of data generation and regional authorities that facilitated data collection.
Abbreviations
- AHAs
Antihyperglycemic Agents
- ADA
American Diabetes Association
- CPS
Clinical Pharmacy Services
- CPI
Clinical Pharmacist Intervention
- DRPs
Drug-Related Problems
- IDF
International Diabetes Federation
- IQR
Interquartile Range
- LMICs
Low- and middle-income countries
- MTM
Medication Therapy Management
- pADE
Potential Adverse Drug Event
- PCNE
Pharmaceutical Care Network Europe
- QUM
Quality Use of Medicine
- SD
Standard Deviation
- SOP
Standard Operating Procedure
- WHO
World Health Organization
- T2DM
Type 2 Diabetes Mellitus
- UKPDS
United Kingdom Prospective Diabetes Study
Author contributions
Phuong Thi Xuan Dong: Conceptualization, Methodology, Data collection, Formal analysis, Writing – Original Draft, Writing – Review & Editing. Thao Thi Nguyen: Conceptualization, Methodology, Data collection, Formal analysis, Writing – Original Draft, Writing – Review & Editing. Phuong TXD and Thao TN contributed equally to the study Hang Thi Thuy Hang: Data collection, Formal analysis, Writing – Review & Editing. Anh Van Le: Methodology, Writing – Review & Editing Thuy Thanh Thi Nguyen: Methodology, Writing – Review & Editing Anh Kim Thi Nguyen: Methodology, Writing – Review & Editing Chinh Thu Nguyen: Methodology, Writing – Review & Editing Van Thuy Thi Pham: Conceptualization, Methodology, Writing – Review & Editing. All authors read and approved the final manuscript.
Funding
This research received no specific grant from any funding agency in public, commercial or not-for-profit sectors.
Data availability
All data generated and analysed during the current study are available from the corresponding author on reasonable request.
Declarations
Ethics approval and consent to participate
Ethics approval was obtained from the Ethical Committee in Biomedical Research of Friendship Hospital, Vietnam. The study was performed in accordance with the Declaration of Helsinki. As the study involved minimal risk, no collection of identifiable data, and was embedded in routine care, the Committee formally waived the requirement for written informed consent, in accordance with Vietnamese ethical regulations. All data were anonymized prior to analysis to ensure the protection of patient privacy and confidentiality.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Phuong Thi Xuan Dong and Thao Thi Nguyen contributed equally to this work.
References
- 1.Saeedi P, Petersohn I, Salpea P, Malanda B, Karuranga S, Unwin N, et al. Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: results from the international diabetes federation diabetes Atlas, 9(th) edition. Diabetes Res Clin Pract. 2019;157:107843. [DOI] [PubMed] [Google Scholar]
- 2.Kirkman MS, Briscoe VJ, Clark N, Florez H, Haas LB, Halter JB, et al. Diabetes in older adults: a consensus report. J Am Geriatr Soc. 2012;60(12):2342–56. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Salvi F, Marchetti A, D’Angelo F, Boemi M, Lattanzio F, Cherubini A. Adverse drug events as a cause of hospitalization in older adults. Drug Saf. 2012;35(Suppl 1):29–45. [DOI] [PubMed] [Google Scholar]
- 4.Al-Dahshan A, Kehyayan V. Prevalence and predictors of potentially inappropriate medication prescription among older adults: A Cross-Sectional study in the state of Qatar. Drugs - real World Outcomes. 2021;8(1):95–103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.13. Older adults: standards of care in Diabetes-2024. Diabetes Care. 2024;47(Suppl 1):S244–57. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Clegg A, Young J, Iliffe S, Rikkert MO, Rockwood K. Frailty in elderly people. Lancet (London England). 2013;381(9868):752–62. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Maher RL, Hanlon J, Hajjar ER. Clinical consequences of polypharmacy in elderly. Exp Opin Drug Saf. 2014;13(1):57–65. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.American College of Clinical Pharmacy. The definition of clinical pharmacy. Pharmacotherapy. 2008;28(6):816–7. [DOI] [PubMed] [Google Scholar]
- 9.Kaboli PJ, Hoth AB, McClimon BJ. Clinical pharmacists and inpatient medical care: a systematic review. Arch Intern Med. 2006;166(9):955–64. [DOI] [PubMed] [Google Scholar]
- 10.BondCA CLR. Clinical pharmacy services, pharmacy staffing, and hospital mortality rates. Pharmacotherapy. 2007;27(4):481–93. [DOI] [PubMed] [Google Scholar]
- 11.Mekonnen AB, McLachlan AJ, Brien JA. Effectiveness of pharmacist-led medication reconciliation programmes on clinical outcomes at hospital transitions: a systematic review and meta-analysis. BMJ Open. 2016;6(2):e010003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Pousinho S, Morgado M, Falcão A, Alves G. Pharmacist interventions in the management of type 2 diabetes mellitus: A systematic review of randomized controlled trials. J Managed Care Specialty Pharm. 2016;22(5):493–515. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Coutureau C, Slimano F, Mongaret C, Kanagaratnam L. Impact of Pharmacists-Led interventions in primary care for adults with type 2 diabetes on HbA1c levels: a systematic review and meta-analysis. Int J Environ Res Public Health. 2022;19(6). [DOI] [PMC free article] [PubMed]
- 14.Dong PTX, Trinh HT, Nguyen DH, Nguyen ST, Pham VTT, Ngo HB, et al. Implementing clinical pharmacy activities in hospital setting in vietnam: current status from a National survey. BMC Health Serv Res. 2022;22(1):878. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Barry MJ, Edgman-Levitan S. Shared decision making–pinnacle of patient-centered care. N Engl J Med. 2012;366(9):780–1. [DOI] [PubMed] [Google Scholar]
- 16.TN T, TT H. Effectiveness of pharmacists’ counseling services in medication adherence among type 2 diabetic out-patients at Hai Phong medical university hospital. J Pharm Res Drug Inform. 2024;19:11. [Google Scholar]
- 17.Trinh HT, Nguyen HTL, Pham VTT, Ba HL, Dong PTX, Cao TTB, et al. Hospital clinical pharmacy services in Vietnam. Int J Clin Pharm. 2018;40(5):1144–53. [DOI] [PubMed] [Google Scholar]
- 18.Nguyen-Thi HY, Nguyen-Ngoc TT, Le NH, Le NQ, Le NDT. Current status of clinical pharmacy workforce, services and clinical pharmacist recruitment in Ho Chi Minh City, Vietnam. Int J Health Plann Manage. 2020;35(5):1205–18. [DOI] [PubMed] [Google Scholar]
- 19.Nguyen-Thi HY, Nguyen-Ngoc TT, Do-Tran MT, Do DV, Pham LD, Le NDT. Job satisfaction of clinical pharmacists and clinical pharmacy activities implemented at Ho Chi Minh city, Vietnam. PLoS ONE. 2021;16(1):e0245537. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Yasmin S, Raveendran AV, Jayakrishnan B, Sreelakshmi R, Jose R, Chandran V, et al. How common are the errors in insulin injection techniques – a real world study. Int J Diabetes Technol. 2023;2(4).
- 21.Ji J, Lou Q. Insulin pen injection technique survey in patients with type 2 diabetes in Mainland China in 2010. Curr Med Res Opin. 2014;30(6):1087–93. [DOI] [PubMed] [Google Scholar]
- 22.Struijs JN, Baan CA, Schellevis FG, Westert GP, van den Bos GA. Comorbidity in patients with diabetes mellitus: impact on medical health care utilization. BMC Health Serv Res. 2006;6:84. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Lipska KJ, Krumholz H, Soones T, Lee SJ. Polypharmacy in the aging patient: A review of glycemic control in older adults with type 2 diabetes. JAMA. 2016;315(10):1034–45. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Jüngst C, Gräber S, Simons S, Wedemeyer H, Lammert F. Medication adherence among patients with chronic diseases: a survey-based study in pharmacies. QJM: Monthly J Association Physicians. 2019;112(7):505–12. [DOI] [PubMed] [Google Scholar]
- 25.Spinewine A, Schmader KE, Barber N, Hughes C, Lapane KL, Swine C, et al. Appropriate prescribing in elderly people: how well can it be measured and optimised? Lancet (London, England). 2007;370(9582):173 – 84. [DOI] [PubMed]
- 26.Allemann SS, van Mil JW, Botermann L, Berger K, Griese N, Hersberger KE. Pharmaceutical care: the PCNE definition 2013. Int J Clin Pharm. 2014;36(3):544–55. [DOI] [PubMed] [Google Scholar]
- 27.Nkansah N, Mostovetsky O, Yu C, Chheng T, Beney J, Bond CM, et al. Effect of outpatient pharmacists’ non-dispensing roles on patient outcomes and prescribing patterns. Cochrane Database Syst Rev. 2010;2010(7):Cd000336. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Hassan F, Hatah E, Ali AM, Wen CW. The intervention strategies and service model for pharmacist-led diabetes management: a scoping review. BMC Health Serv Res. 2023;23(1):46. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Iqbal MZ, Khan AH, Iqbal MS, Syed Sulaiman SA. A review of Pharmacist-led interventions on diabetes outcomes: an observational analysis to explore diabetes care opportunities for pharmacists. J Pharm Bioallied Sci. 2019;11(4):299–309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Hatah E, Braund R, Tordoff J, Duffull SB. A systematic review and meta-analysis of pharmacist-led fee-for-services medication review. Br J Clin Pharmacol. 2014;77(1):102–15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Chen JH, Ou HT, Lin TC, Lai EC, Kao YH. Pharmaceutical care of elderly patients with poorly controlled type 2 diabetes mellitus: a randomized controlled trial. Int J Clin Pharm. 2016;38(1):88–95. [DOI] [PubMed] [Google Scholar]
- 32.Chung WW, Chua SS, Lai PS, Chan SP. Effects of a pharmaceutical care model on medication adherence and glycemic control of people with type 2 diabetes. Patient Prefer Adherence. 2014;8:1185–94. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Cortez DN, Macedo MML, Souza DAS, dos Santos JC, Afonso GS, Reis IA, et al. Evaluating the effectiveness of an empowerment program for self-care in type 2 diabetes: a cluster randomized trial. BMC Public Health. 2017;17(1):41. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 34.Mahwi TO, Obied KA. Role of the pharmaceutical care in the management of patients with type 2 diabetes mellitus. Int J Pharm Sci Res. 2013;4(4):1363. [Google Scholar]
- 35.Mourão AO, Ferreira WR, Martins MA, Reis AM, Carrillo MR, Guimarães AG, et al. Pharmaceutical care program for type 2 diabetes patients in brazil: a randomised controlled trial. Int J Clin Pharm. 2013;35(1):79–86. [DOI] [PubMed] [Google Scholar]
- 36.Sarayani A, Mashayekhi M, Nosrati M, Jahangard-Rafsanjani Z, Javadi M, Saadat N, et al. Efficacy of a telephone-based intervention among patients with type-2 diabetes; a randomized controlled trial in pharmacy practice. Int J Clin Pharm. 2018;40(2):345–53. [DOI] [PubMed] [Google Scholar]
- 37.Siaw MYL, Ko Y, Malone DC, Tsou KYK, Lew YJ, Foo D, et al. Impact of pharmacist-involved collaborative care on the clinical, humanistic and cost outcomes of high-risk patients with type 2 diabetes (IMPACT): a randomized controlled trial. J Clin Pharm Ther. 2017;42(4):475–82. [DOI] [PubMed] [Google Scholar]
- 38.Xin C, Xia Z, Jiang C, Lin M, Li G. Effect of pharmaceutical care on medication adherence of patients newly prescribed insulin therapy: a randomized controlled study. Patient Prefer Adherence. 2015;9:797–802. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 39.Wubben DP, Vivian EM. Effects of pharmacist outpatient interventions on adults with diabetes mellitus: a systematic review. Pharmacotherapy. 2008;28(4):421–36. [DOI] [PubMed] [Google Scholar]
- 40.Bukhsh A, Tan XY, Chan KG, Lee LH, Goh BH, Khan TM. Effectiveness of pharmacist-led educational interventions on self-care activities and glycemic control of type 2 diabetes patients: a systematic review and meta-analysis. Patient Prefer Adherence. 2018;12:2457–74. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 41.Intensive blood-glucose. Control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet. 1998;352(9131):837–53. [PubMed] [Google Scholar]
- 42.Federation ID. Managing older people with type 2 diabetes: Global guideline. 2014.
- 43.Sanchez-Molina AI, Benrimoj SI, Ferri-Garcia R, Martinez-Martinez F, Gastelurrutia MA, Garcia-Cardenas V. Development and validation of a tool to measure collaborative practice between community pharmacists and physicians from the perspective of community pharmacists: the professional collaborative practice tool. BMC Health Serv Res. 2022;22(1):649. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 44.Rosenthal M, Austin Z, Tsuyuki RT. Are pharmacists the ultimate barrier to pharmacy. Pract Change? 2010;143(1):37–42. [Google Scholar]
- 45.Alzahrani AM, Rambo R, Alotain F, Naeem A, Alzhrani RM, Albaradi MA, et al. Determinants of patient satisfaction with discharge pharmacy services at a tertiary care center in Jeddah, KSA. Integr Pharm Res Pract. 2024;13:155–64. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 46.Park JY, Yuen J. Exploring patient willingness to pay for pharmacist-led clinical services in a primary care setting. Can Pharm J (Ott). 2022;155(3):157–63. [DOI] [PMC free article] [PubMed]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
All data generated and analysed during the current study are available from the corresponding author on reasonable request.