To determine the effectiveness of the Chronic Care Model (CCM) on self-management behaviour and glycaemic control compared to normal care among adults with type 2 diabetes mellitus.

1) To determine the mean change in glycated haemoglobin among subjects allocated to the Chronic Care Model compared with those receiving usual care.

2) To determine the mean change in self-management behaviour among subjects allocated to the Chronic Care Model compared with those receiving usual care.

This study was a single-blinded randomised controlled trial comprising an intervention group that received Chronic Care Model-based care and a control group that received the usual model of care.

The study was conducted at the General Outpatient Clinic (GOPC) of the Federal University Teaching Hospital, Lafia, (formerly Dalhatu Araf Specialist Hospital) Lafia. The state had an estimated population of 2,886,000, while Lafia had a projected population of 509,300 as at 2022 [28].

The GOPC operates weekdays from 8:00 a.m. to 4:00 p.m. and is staffed by medical officers, resident doctors, and family medicine consultants. Unpublished outpatient records indicate that approximately 13 to 15 patients aged ≥ 40 years with diabetes mellitus attend daily.

The study population comprised adults aged 40 years and above with confirmed type 2 diabetes mellitus.

Sample size was determined using the formula for comparison of mean differences between two groups [29].

where:

N = minimum sample size required for each group.

Z_α/2 = 1.96, representing the t-value for a 95% confidence level when α = 0.05.

Z_β = 0.84, representing the t-value for 80% power when β = 0.2.

I = mean difference of the effect of CCM on glycaemic control in the intervention group from a previous study in Pakistan = 1.06 [30].

c = mean difference of the effect of usual care on glycaemic control in the control group from a previous study in Kenya = 0.60 [31].

Δ = mean difference between the study groups = 0.46.

Therefore:

N = (1.96 + 0.84)² (1.06² + 0.60²)/0.46²

N = 7.84 × 2.19/0.21

N ≈ 82

Accounting for a 10% attrition rate, a total of 90 participants (45 per group) were recruited.

Participants were randomly allocated into control (Group A) and intervention (Group B) groups using opaque envelopes containing numbered slips. Odd numbers were assigned to the control group, and even numbers to the intervention group.

3.5.1. Inclusion Criteria

Individuals aged ≥ 40 years and diagnosed with type 2 diabetes mellitus for ≥6 months, with good medication adherence and availability during the study period.

3.5.2. Exclusion Criteria

Individuals who were pregnant, with major psychiatric illness, or were unlikely to complete follow-up.

1) Structured questionnaires for biodata and socioeconomic characteristics.

2) Self-management behaviour records.

3) The Diabetes Self-Management Questionnaire (DSMQ), a validated tool for assessing diabetes self-care behaviours [32]-[35].

4) Clover A1c point-of-care analyser for HbA1c measurement.

After written informed consent, questionnaires were interviewer-administered. The control group received routine care, while the intervention group received structured CCM-based education and follow-up. Of the 45 participants in the control group, 41 completed the study, while 43 of 45 completed in the intervention group, supporting internal validity. All patients were seen at in the consulting rooms at the GOPD of the center and their follow-up visits were scheduled at 0, 4, 8 and 12 weeks. The participants in the two groups were seen on different follow-up dates to avoid contamination during the entire study. Full participation of each participant in this study entailed four clinic visits, completely filled study questionnaires, provision of HbA1c and FBG results pre- and post-intervention. Any participant that did not meet these criteria was categorized as been lost to follow-up.

3.7.1. Control Group

Each patient in this arm was seen at an average of 20 minutes. The diabetes self-management instruction sheet was used as a structured guide for consultation to the usual care group and for ease of replication in similar studies in the future. They were verbally advised on dietary and lifestyle modification as per standard procedure. The following activities were carried out in each clinic visit:

At the first encounter (recruitment point), the purpose of the study was explained to each participant and an informed written consent form for the study was given. Their BP, weight and height were checked and BMI were recorded. HbA1C and FBG were requested to be presented during the next visit. They were verbally counselled on dietary and medication adherence. Their medications were reviewed and they were advised to check their FBG at each visit as they usually did.At the second and third visit (4^th and 8^th week), the participants were given verbal dietary and medication adherence counselling. Their medications were reviewed and any other health challenges they presented with were addressed. They were asked to do HbA1c and FBG to be presented at the last visit.During the last encounter (12^th week), their BP, weight, height and BMI were recorded. Self-management behaviour of each participant was also recorded during this visit using the self-management behaviour form. They were encouraged to adhere to their medications and keep to their usual follow-up as scheduled with their doctors.

3.7.2. Intervention Group

This group of patients were seen at an average of 35 minutes. In addition to what was done for the control group, the following was included:

1) A simple protocol was designed and faithfully adhered to. Primarily, caregivers including doctors and nurses were trained on motivational interviewing skills. Managing physicians and selected nurses were coached on communication skills.

2) Proper documentation of results of each participant was ensured and made easily available on each appointment day. The clinical information system which is a component of CCM was achieved through this approach. The following activities were carried out during each clinic visit:

3) For the participants who were obese, they were encouraged to lose 0.5 kg of body weight weekly by carrying out moderate intensity exercise at least four or five days in a week such as brisk walking for at least 30 minutes per day, skipping for 15 minutes.

4) To significantly reduce alcohol or abstain.

5) To stop smoking.

6) To consume plenty of fresh fruits and vegetables daily-at least five servings each day, reduce salt intake and oily meals.

7) To adhere to medications by setting reminders on phone or asking family member/friend to remind them daily.

8) To practice foot care daily by checking for sores, and cracks, wearing of soft padded shoes and to take caution when cutting nails by using a nail cutter instead of razor blade.

9) To get their personal glucometer to monitor their sugar level at home, and symptoms of hypo-hyper glycemia and steps to take.

At the second and third visit (4^th and 8^th week), their hospital records were made available by the designated record officer. Pre-intervention HbA1c was recorded and the form given to the participants was reviewed and assessed.

Data were analysed using SPSS. Descriptive statistics summarised baseline characteristics. Independent-samples t-tests compared continuous variables, while chi-square and Fisher’s exact tests analysed categorical variables. Significance was set at p < 0.05, and analysis followed an intention-to-treat approach.

The study adhered to ethical principles approved by the ethics committee of FUTH, Lafia. All participants provided written informed consent prior to enrolment. Confidentiality was ensured, and all data were anonymised and securely stored.

Because significant baseline imbalances were observed in HbA1c and diastolic blood pressure, and fasting glucose showed borderline imbalance, adjusted analyses were conducted using ANCOVA with baseline values entered as covariates (See Table 8).

Table 8. Baseline-adjusted treatment effects.

significance set at *p < 0.05.

4.1.1. Glycated Haemoglobin (Primary Outcome)

After adjusting for baseline HbA1c:

Adjusted mean difference = −0.67%;

95% CI: −0.91 to −0.43;

p < 0.001.

This indicates a statistically and clinically significant greater reduction in HbA1c among participants receiving the intervention compared with controls.

4.1.2. Fasting Blood Glucose

After baseline adjustment:

Adjusted mean difference = −1.5 mmol/L;

95% CI: −2.3 to −0.7;

p < 0.001.

4.1.3. Systolic Blood Pressure

Baseline-adjusted analysis showed:

Adjusted mean difference = −3.4 mmHg;

95% CI: −5.8 to −1.0;

p = 0.005.

4.1.4. Diastolic Blood Pressure

After adjusting for baseline values:

Adjustedmeandifference=−0.3mmHg;

95% CI: −1.6 to 1.0;

p = 0.62.

No statistically significant intervention effect was observed.

4.1.5. Body Mass Index

After baseline adjustment:

Adjusted mean difference = 0.4 kg/m²;

95% CI: −1.2 to 2.0;

p = 0.61.

No significant difference was observed between groups.

After adjusting for baseline imbalances, the intervention produced statistically significant improvements in:

Glycaemic control (HbA1c)Fasting blood glucoseSystolic blood pressure

No significant effects were observed for:

Diastolic blood pressureBody mass index

The magnitude of HbA1c reduction (0.67%) is clinically meaningful and consistent with structured diabetes self-management interventions among adults with type 2 diabetes (See Table 9).

Table 9. Multiple linear regression predicting HbA1c from self-management behaviours post intervention.

*(p < 0.05).

HbA1c = β₀ + β₁ (Medication adherence) + β₂ (Dietary control) + β₃ (Physical activity) + β₄ (Glucose monitoring) + ε.

At baseline, participants in both the intervention and control groups exhibited suboptimal engagement in lifestyle-related self-management behaviours, particularly dietary control, physical activity, foot care, and blood glucose monitoring. In contrast, medication adherence scores were relatively high. This pattern is consistent with previous Nigerian studies, which have repeatedly shown that while patients often adhere to prescribed medications, adherence to behavioural components of diabetes care remains poor [12]-[14]. Similar findings have been reported across sub-Saharan Africa, where structural barriers such as limited access to glucometers, financial constraints, inadequate diabetes education, and sociocultural beliefs undermine sustained self-care [7][8][15].

Following the intervention, participants exposed to CCM-based care demonstrated significant improvements across multiple self-management domains, including dietary modification, physical activity, glucose monitoring, and foot care. These improvements were consistently greater than those observed in the control group, which received usual care. The magnitude and breadth of behavioural change observed in the intervention group align closely with the core principles of the CCM, particularly structured self-management support, proactive follow-up, and continuous patient–provider interaction [14].

Comparable improvements have been reported in studies from high-income settings, where CCM-based interventions have been shown to enhance diabetes self-care behaviours and patient activation [21][22][24]. Importantly, the present study extends this evidence to a resource-constrained Nigerian context, demonstrating that meaningful behavioural change is achievable even in settings with limited infrastructure when care delivery is systematically restructured.

The largest behavioural gains were observed in glucose monitoring and dietary practices, domains that were explicitly targeted through education, goal setting, and reinforcement during follow-up visits. This finding is consistent with prior work showing that structured education and regular feedback are critical drivers of behaviour change in chronic disease management [23][27].

The improvements in self-management behaviours translated into superior clinical outcomes. Participants in the intervention group experienced significantly lower post-intervention fasting blood glucose levels and a greater reduction in glycated haemoglobin compared with those receiving usual care. Although post-intervention HbA1c values were similar between groups, the significantly larger mean reduction observed in the intervention arm indicates a clear intervention effect over the 12-week follow-up period.

These findings are consistent with evidence from systematic reviews and meta-analyses demonstrating that CCM-based interventions are associated with modest but clinically meaningful reductions in HbA1c [26][31]. Even relatively small reductions in HbA1c have been shown to substantially reduce the risk of microvascular and macrovascular complications, a consideration of particular relevance in Nigeria, where access to advanced diabetes care is limited and complication-related morbidity remains high.

Regression analysis revealed that medication adherence, dietary control, and glucose monitoring were significant independent predictors of glycated haemoglobin levels, collectively explaining 43% of the variance in HbA1c. This finding reinforces the central role of self-management behaviours in determining glycaemic outcomes and is consistent with previous studies showing that behavioural factors are often stronger predictors of metabolic control than demographic or clinical characteristics [14][18][19][22].

While physical activity showed a favourable association with HbA1c, this relationship was not statistically significant. Similar findings have been reported in other studies, where improvements in physical activity behaviours did not immediately translate into measurable changes in glycaemic indices [31].

5.5.1. Strengths

Randomised controlled design;

High participant retention;

Use of validated instruments;

Use of objective biochemical outcomes (HbA1c, FBG).

5.5.2. Limitations

Short follow-up duration;

Single centre design;

Per protocol rather than intention to treat analysis.

The findings of this study have important implications for diabetes care delivery in Nigeria and similar low- and middle-income settings. The findings suggest that structured CCM-based diabetes management can:

Improve glycaemic controlReduce cardiovascular risk factorsEnhance chronic disease outcomes in Nigerian tertiary settings

Integration of CCM principles into routine diabetes care may reduce complication rates and healthcare burden.

1) Adoption of structured diabetes self-management programmes in tertiary hospitals.

2) Integration of CCM components into national diabetes care guidelines.

3) Longer-duration interventions to assess sustained metabolic and anthropometric effects.

4) Multi-centre trials to improve generalizability.

5) Inclusion of intention-to-treat analyses in future studies.