International Journal of Clinical Pharmacy

, Volume 37, Issue 5, pp 734–738 | Cite as

Impact of a pharmacotherapy plan to improve adherence for patients with type-2 diabetes and hypertension in a Chilean hospital

  • Alejandra Soto
  • Ximena Avila
  • Pia Cordova
  • Pola Fernandez
  • Mariela Lopez
  • Lorenzo A. Villa
  • Felipe Morales
Short Research Report


Background Non-adherence to prescribed treatment is a principle cause of treatment failure in patients with chronic diseases, such as type 2 diabetes mellitus (T2DM) and hypertension. Improved patient monitoring and education have been shown to improve adherence and clinical outcomes. Objective This study evaluates the impact of a pharmacotherapy optimization plan centered on patient education that was implemented at a hospital in Arauco, Chile. Methods A prospective study was conducted using 50 randomly selected patients diagnosed with both T2DM and hypertension. Each patient participated in three successive interview sessions over 6 months. At each session, the following variables were evaluated by a pharmacist: blood pressure, HbA1c, adherence to prescribed medication, and patient knowledge of disease. Results Significant decreases were observed for HbA1c (<0.001), and SBP (<0.001), with stronger and more significant decreases observed for females. Patient adherence to prescribed medication also improved, but not significantly. The number of patients with full knowledge of their diseases increased significantly (p < 0.001) from 10 to 66 %. Conclusion This study suggests that the incorporation of a pharmacotherapeutic optimization plan for patients with chronic diseases can have a positive impact on the control of chronic diseases, such as T2DM and hypertension.


Chile Medication adherence Patient education Pharmacotherapeutic optimization plan 

Impact of findings on practice

  • Pharmacotherapy education and adherence monitoring may produce improved clinical results in patients with type-2 diabetes and hypertension in Chile.

  • Hospitals in which poor patient adherence is prevalent can benefit from pharmacotherapy education programs.


The World Health Organization (WHO) defines adherence as the extent to which a person’s behavior, such as taking medication, following a diet, and implementing lifestyle changes, corresponds with recommendations from health care providers [1].

Lack of adherence is an important public health problem and is considered one of the most common causes of treatment failure in chronic diseases, including type 2 diabetes mellitus (T2DM) and hypertension. There is a clear relationship between non-adherence and a lack of metabolic control in diabetic patients and between non-adherence and lack of blood pressure control in hypertensive patients [2].

In Chile, chronic diseases such as T2DM and hypertension are prevalent in the adult population (9 and 27 %, respectively). Globally, in patients with both T2DM and hypertension, adherence to drug treatment ranges between 36 and 93 %. In Chile, published data regarding adherence are limited; however, some research indicates that adherence in T2DM patients is approximately 60 % [3].

The control of chronic diseases such as T2DM and hypertension involves adherence not only to medications, but also to broader treatment plans, which include healthy lifestyles. Patient and health system characteristics and the doctor-patient relationship also influence adherence, and evidence has suggested that patients with more knowledge or information about their diseases are more adherent [4].

Aims of the study

To evaluate the outcomes of a pharmacotherapy optimization plan, with patient education as its cornerstone, to improve adherence in patients with both T2DM and hypertension. The specific outcomes are (1) patient knowledge about the diseases and treatments; (2) blood pressure and glycated hemoglobin (HbA1c); and (3) adherence.

Ethical approval

Ethical approval was granted by the ethics committee of the Hospital of Arauco and by the research committee of the Faculty of Pharmacy at University of Concepción.


Study design and patients

A prospective study was conducted using 50 randomly selected patients from a group of patients over 18 years of age diagnosed with both T2DM and hypertension who receive outpatient care at San Vicente Hospital, a rural 100-bed healthcare center in Arauco, Chile serving a predominately native Mapuche population. This setting was chosen due to the particularly high prevalence of hypertension and T2DM in its patient population. Many of these patients show poor clinical control of these conditions.

Hypertension was defined as systolic blood pressure (SBP) equal to or greater than 140 mmHg and diastolic blood pressure (DBP) equal to or greater than 90 mmHg [5]. T2DM was defined as the presence of the following symptoms: polydipsia, polyuria, polyphagia, and weight loss; and glycaemia with values greater than or equal to 200 mg/dL without regard to the time elapsed since the last meal [6]. All patients were already under pharmacological treatment for a minimum of a year. Patients who agreed to participate in this study provided informed consent as stipulated by the ethical committee of the hospital.

Intervention and measures

Each patient participated in three 30–45 min-long successive interview sessions over a period of 4–6 months. These sessions were conducted at San Vicente Hospital by pharmacists. In all three sessions, the following variables were evaluated: blood pressure and HbA1c levels, other anthropometric parameters, such as body mass index (BMI), adherence to prescribed medication, and patient knowledge. Additionally, patients visited the San Vicente Hospital pharmacy every 30 days to refill their prescriptions. If these visits did not coincide with one of the three interviews, then adherence was measured by a pharmacy technician at these visits.

SBP and DBP were measured three times in a sitting position with an oscillometric device at 2-min intervals. HbA1c levels were obtained from clinical records. Adherence to medication was quantified by the percentage of pills remaining in the bottles issued to patients. Patients received a quantity of pills exceeding the number required before their next visit and were instructed to return all medication including any surplus. Pill count was calculated as: (no. of pills dispensed − no. of pills returned)/number of pills prescribed × 100. A pill count between 80 and 110 % was considered good adherence. [7] It was assumed that the unreturned pills were ingested by the patient. Patients above or below this range were classified as non-adherent.

Patients’ knowledge of their diseases was evaluated using the “Battle’s test,” which included three items: (1) Is hypertension/diabetes a disease for life? (2) Can it be controlled with diet and medication? and (3) List two or more organs that can be damaged by elevated blood pressure/T2DM. Patients were considered uninformed if they failed to answer correctly at least one item. On the other hand, patients were considered informed only if they correctly answered all three questions.

In the initial session, pharmacists developed a pharmacotherapeutic plan tailored to each patient. These plans involved providing the patient with written and verbal educational material, including information regarding how and when to take medication as well as the correct quantity, pathologies and their causes and consequences, the purpose of treatment, and adverse effects. A calendar was provided to each patient with the aim of preventing forgetfulness in taking medication and to help organize the taking of medications.

In the second interview, these plans were reevaluated according to the pharmacists’ discussions with each patient. Patients were also invited to bring family members to the second session in order to involve them in the treatment plan. In the third session, pharmacists completed a final discussion with patients regarding their pharmacotherapeutic plans.

Statistical analysis

Descriptive statistics were used to summarize the data. Fisher’s exact test was used to assess the change in patients’ level of pharmacotherapeutic adherence and knowledge of their diseases. Student’s t-tests for related samples were used to determine the existence of a statistically significant (p value <0.05) difference between the initial and final session in SBP and DBP, HbA1c, and BMI. Analyses were performed using SPSS version 20 (IBM Software).


Table 1 summarizes the characteristics of participating patients at baseline. The average age for the study sample was 60 years, and there were no significant differences in the variables studied when the sample was stratified by sex. A high percentage of patients (49 %) were overweight or obese. Overall, patients included in the study exhibited poor control of their diseases at baseline, with high levels of HbA1c (>7 %) and high SBP (>140 mmHg).
Table 1

baseline patient characteristics


Male (n = 17)

Female (n = 33)

Total (n = 50)

p value

Age (years)

62.0 ± 13.0

58.0 ± 7.0

60.0 ± 10.0


Weight (kg)

86.0 ± 18.0

85.7 ± 21.0

85.9 ± 19.9


BMI (kg/m2 ± SD)

32.1 ± 7.0

35.9 ± 7.6

34.6 ± 7.6


Patients classification according to BMI

Normal (BMI = 18.5–24.9)

1 (5.8)

0 (0.0)

1 (2.0)


Overweight (IMC ≥ 25)

6 (35.3)

8 (24.2)

14 (28.0)

Obesity level I (IMC = 30–34.9)

6 (35.3)

10 (30.3)

16 (32.0)

Obesity level II (IMC = 35–39.9)

2 (11.8)

7 (21.2)

9 (18.0)

Obesity level III (IMC ≥ 40)

2 (11.8)

8 (24.2)

10 (20.0)

HbA1c (%)

10.2 ± 2.1

9.0 ± 2.4

9.4 ± 2.3


Systolic blood pressure (mmHg)

145.0 ± 19.0

159.0 ± 18.0

151.0 ± 19.0


Diastolic blood pressure (mmHg)

80.0 ± 11.0

85.0 ± 12.0

82.0 ± 12.0


Variables are presented in mean ± standard deviation

HbA1c Glycated Hemoglobin, BMI body mass index, in kg/m2

Table 2 shows the difference between the study variables at baseline and at the conclusion of the study. Over the course of the study, the number of patients found to be adherent increased from 30 to 46 %; however, this difference was not significant (p value 0.099). There was no significant difference between females and males when adherence status was compared at the beginning (116.8 ± 97.4 versus 75.4 ± 32.6, respectively, p value 0.096) and end (97.5 ± 74.1 versus 82.2 ± 53.4, respectively, p value 0.4541) of the study. Patients’ knowledge of their diseases increased significantly (p < 0.001) over the course of the study, with the percent of patients with full knowledge increasing from 10 to 66 %.
Table 2

Comparison of variables at the beginning and final session


Initial n (%)

Final n (%)

p value

Pill counts


15 (30)

23 (46)



35 (70)

27 (54)

Disease knowledge


5 (10)

33 (66)


Does not know

45 (90)

17 (34)

Clinical variables under study (n = 50) (all values are mean ± SD)

BMI (kg/m2)

34.6 ± 7.5

34.6 ± 7.7


HbA1c (%)

9.4 ± 2.3

8.8 ± 2.4


Systolic blood pressure (mmHg)

151.0 ± 19.0

135.0 ± 16.0


Diastolic blood pressure (mmHg)

82.0 ± 12.0

78.0 ± 10.0


BMI body mass index, HbA1c glycated hemoglobin

** HbA1c (%): It was considered diabetes mellitus under control when values of HbA1c ≤ 7 % were reached

Significant decreases were also observed for HbA1c (<0.001), and SBP (<0.001). BMI and DBP also decreased but not significantly. Stratified by sex, stronger and more significant decreases were observed for females in terms of both HbA1c (0.63 %, p value: 0.003) and SBP (17 mmHg, p value <0.001). For males, only the decrease in SBP (14 mmHg, p value <0.001) was significant.


Chronic diseases, including hypertension and T2DM, require continuous patient care. To achieve therapeutic goals proper adherence to pharmacotherapeutic treatment is fundamental. Many factors may influence adherence rates among patient populations. Manteuffel et al. [8], for example, found that women are less adherent than men to treatments for chronic diseases. This current study, however, observed no statistically significant differences between sexes regarding adherence. Another investigation demonstrated that only 20 % of diabetic patients achieving a BMI ≤ 24.9 kg/m2 reached metabolic control [9]. This finding was reinforced by our study, which found that only 2 % of the studied population reached that level.

The degree of patient adherence increased, though not significantly, over the course of the study. Some studies set the adherence rate of patients with chronic diseases at 50 %. In patients with hypertension, it is estimated that half of those who start antihypertensive therapy will abandon their treatments before a year. Duran et al. estimate adherence status to be 54.2 % for T2DM patients, while de Vries et al. [10] estimate the degree of adherence to be 38 %, with forgetfulness being the main cause in both studies.

Intervention programs and monitoring strategies have proved effective at improving outcomes in patients with chronic conditions. Morgado et al. [11] determined that a pharmaceutical intervention program aimed at changing factors affecting pharmacotherapy adherence, led to statistically significant decreases in blood pressure. Meanwhile, other studies have demonstrated the effectiveness of similar programs on metabolic parameters in diabetic patients.

In this study, a significant decrease in HbA1c was observed. It should be noted that a decrease of at least 1 % from baseline HbA1c is associated with a 21 % reduction in the risk of death associated with diabetes and a 14 % reduction in the risk of acute myocardial infarction over 10 years [12].


One limitation of this research is its relatively short time period, which makes it difficult to demonstrate a significant reduction in some clinical outcomes. Another limitation is that the pill count method of measuring adherence that was used in this study includes the assumption that all unreturned pills were ingested by patients. This may not always be accurate, as patients may have lost pills or not returned them for some other reason. This study also did not consider patients’ coexisting conditions, which may have impacted clinical outcomes. Finally, while this exploratory pilot study of 50 patients suggests that a pharmacotherapeutic plan may have a positive effect on patient outcomes, education and adherence, a more robust study design (e.g., randomized controlled trial) is needed to confirm the impact of this plan.


The incorporation of a pharmacotherapeutic optimization plan based on providing education to improve the knowledge and adherence of patients with chronic conditions may have a positive impact on the degree of control of chronic diseases, such as T2DM and hypertension.



The authors would like to thank the staff of Hospital San Vicente for facilitate the premises to run this study. We acknowledge the participation of Mr. Michael Levengood M.Sc. in the process of editing of this paper.


This study was not funded by any grant.

Conflicts of interest



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Copyright information

© Koninklijke Nederlandse Maatschappij ter bevordering der Pharmacie 2015

Authors and Affiliations

  • Alejandra Soto
    • 1
  • Ximena Avila
    • 2
  • Pia Cordova
    • 3
  • Pola Fernandez
    • 3
  • Mariela Lopez
    • 3
  • Lorenzo A. Villa
    • 3
  • Felipe Morales
    • 3
  1. 1.CESFAM BicentenarioAraucoChile
  2. 2.Pharmacovigilance UnitSan Vicente HospitalAraucoChile
  3. 3.Facultad de FarmaciaUniversidad de ConcepciónConcepciónChile

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