Diabetes mellitus, a state of chronic hyperglycemia due to multiple causes, is experiencing an alarming progression in the world considered as epidemic . Previous epidemiological studies including DCCT  and UKPDS  have shown the importance of a good glycemic control by appropriate treatment to prevent chronic degenerative complications. Therapeutic guidelines are established by various academic societies    , but are not always correctly followed and the concept of therapeutic inertia initially expresses dichotomy between recognition, identification of a problem and no action to correct it . According to other authors, this concept corresponds with the delay in the intensification of treatment in case a disease is not sufficiently controlled  . What is the extent of the problem? This is a general problem encountered even in centers considered excellent in both clinical practice and training, according to Phillips . This clinical inertia is found both in western and developing countries, as we can see from the following examples: in France, the DI attitude  survey, showed an intensification of treatment only in 39% of patients who needed it. In UK, a large study including more than 80,000 patients  showed an average time to intensify treatment by adding a second oral hypoglycemic agent (OHA) ranging from 2.9 to 1.6 years in patients with HbA1c between 7% and 8%. The average time to add a third OHA ranged from 7.2 to 6.9 years. And the average time to switch to insulin was about 6 years. In USA, the average time to intensify treatment was about one year in patients for whom metformin monotherapy had failed . In Algeria  , a study of 283 Type 2 diabetic patients showed therapeutic inertia for 67.5% of them. Consequences are not negligible for the deleterious effect on the glycemic control of patients  .
The aim of this work is to analyze the anti-diabetic prescriptions in diabetic patients followed externally at the University Hospital Center of Libreville (CHUL), confront them with the concept of therapeutic inertia, and finally propose other approaches to explain this phenomenon, especially andragogy which is interested in adults learning .
2. Materials and Methods
It was a cross-sectional prospective study conducted at the CHUL in October- November 2016 to evaluate the quality of glycemic control of patients by the measurement of HbA1c, referring to the treatment followed by these patients. For each patient coming for his periodic control, we noted the HbA1c level and the treatment followed, in addition to his characteristics. Criteria of inclusion: any patient coming for his periodic control. Criteria of exclusion: after analysis of collected data we rejected files without HbA1c values. HbA1c tests were done in private or public laboratories, as usually, according to the patient’s choice. The CHUL’ laboratory uses the high performance liquid chromatography (HPLC) technique, but there is often shortage of reagents. Private laboratories use immunological techniques. Patients were informed their data will be used anonymously for a study with the authorization of the CHUL’ direction.
Two hundred patients were registered including 126 women (63%) and 74 men (37%). HbA1c analysis was done for 160 patients. Mean age 57.92 years ± 12, 19 (range 21 to 91). Average duration of diabetes is 7.14 years ± 6.84 (range 1 month to 36 years). Results classified in 3 categories according to the level of HbA1c. Group 1, HbAc ≤ 7% is the level wished for majority of patients, group 2, 7% < HbA1c < 8% is a rate acceptable in certain conditions and group 3 HbA1c > 8% reflects poor glycemic control . Group 1 HbA1c ≤ 7%: 74/160 (46.25%), group 2 between 7.1% and 8%: 30/160 (18.75%) and group 3 HbA1c > 8%: 56/160 (35%). This is shown in Figure 1.
Treatment according to the HbA1c classes
Group 1. OHA 59 (79.75%) of which metformin alone 29 (39.18%), metformin + sulfamide 19 (25.67%). Insulin alone, 8 (10.8%), insulin + OHA 4 (5.40%).
Group 2. OHA 21 (70%). Metformin alone 3 (10%), metformin + sulfamide 14 (46.6%). Insulin alone 3 (10%), insulin + OHA 3 (10%).
Group 3. OHA 29 (51.78%). Metformin alone 8 (14.28%), metformin + sulfamide 16 (28.75%). Insulin alone 12 (21.43%), insulin + OHA 12 (21.43%).
Summary of treatment, see Table 1.
Good glycemic control (Hb A1c ≤ 7%) was found in about 46% of diabetic patients followed externally, 80% of whom have done their HbA1c test before coming to control. Our results are very different from what is found in most sub-Saharan African countries where the situation is considered worrying . In a multicenter study in West Africa  , only 21% of patients had done their HbA1c test; the average of this HbA1c was 8.9%, compared to 7.7% in our series and 74% of patients were poorly balanced. In Congo, Makulo et al.  found an average HbA1c level of 9.14% ± 2.7%. How can the results of Gabon be explained? Gabon is a small country and 2/3 of the population lives in Libreville the capital where the offer of care is diversified and the role of the National Health Insurance and Social Security Fund (CNAMGS) which covers medical cares at 80% is undeniable. However, these results concern the urban environment and we do not know what is happening in rural areas. Despite these encouraging results, more than half of patients (54%) are unbalanced. Reasons can be multiple including the problem of therapeutic adherence that we found in 41% of Gabonese diabetics  and probably a lack of therapeutic intensification. Indeed, considering their treatment, the OHA were the most prescribed respectively in 80%, 70% and 51% of the patients of the 3 groups with firstly metformin respectively in 39%, 10% and 14% of the cases. Metformin therefore remains the basis of treatment in accordance with the guidelines and the intensification of treatment is essentially by addition of sulfamides which were proposed as 2nd choice  but are no longer recommended as the second favorite choice in recent guidelines  . Other classes of OHA are little used and there is triple therapy only in 5.35% of cases in the most unbalanced patients, contrary to the guidelines. The use of insulin increases with the glycemic imbalance sometimes alone, sometimes in intensification in addition to ADO. So, the analysis of these prescriptions shows a certain therapeutic inertia, but it can be debated because the choice of sulfamides in 2nd line is probably owed to a long use of these products with rather reassuring studies as ADVANCE for Gliclazide . There are also economic arguments because they are cheap. Despite all the side effects attributed to them: cardio vascular, weight gain, hypoglycemia and increased mortality in diabetics  , prescription of sulfonylurea hypoglycemic agents resists but declines in many countries, competed with other classes of oral antidiabetic drugs  .
Factors incriminated to explain this inertia concern doctors, patients, and the system of care. We have summarized them in Table 2 which reports the point of view of different authors   .
Figure 1. Distribution of HbA1c rates by class.
Table 1. Summary of prescriptions.
Legend: OHA = oral hypoglycemic agent. Met = metformin. Su = sulfamide. IDPP4 = Inhibitors of dipeptidyl peptidase 4. IAG = alpha glucosidase inhibitors.
Table 2. Factors of therapeutic inertia.
Remediation solutions were proposed   but with mixed results and even interventional educational approaches like the “Act on Threes”  failed to overcome this therapeutic inertia. This led us to consider the andragogical concept of “resistance to change”  which is one of the characteristics of the adult learner. Indeed, according to the principles of andragogy, the adult learner is characterized by 1) his autonomy and his self-direction in his learning choices. 2) His need to understand why he has to undertake a new apprenticeship. 3) He has his professional experience which can be an obstacle to a new learning if it is not challenged. 4) He has a readiness to learn if he feels the need, 5) by an internal motivation rather than external pressures, 6) he needs to see the immediate application of what he learns  . All these characteristics make the adult less receptive to change, especially if he receives contradictory information about a new product such as increased risk of amputation under SGLT2 inhibitors . This leads to caution in prescribing this category of oral antidiabetic drug. Therefore it is not “stigmatization”  that can influence the practice of a doctor but rather the consideration of andragogical principles: Valuing the physician, adult learner, experience, while leading him to “change his view”  on his own practice, on the other, the patient he cares for and on the others the medical world to which he belongs, evolution of knowledge and practices. This is the interest of continuous interactive training, communities of practice found in medical practice groups, the fight against “solo” exercise  , which unfortunately still predominates in our sub-Saharan African countries.
The analysis of antidiabetic prescriptions in Libreville shows a therapeutic inadequacy in unbalanced patients, despite the availability of drugs. It’s partially due to therapeutic inertia, a multifactorial phenomenon found all over the world, whose understanding can be enlightened by the andragogical characteristics of the adult learner.
 The Diabetes Control and Complications Trial Research Group (DCCT). (1993) The Effect of Intensive Treatment of Diabetes on the Development and Progression of Long-Term Complications in Insulin-Dependent Diabetes Mellitus. The New England Journal of Medicine, 329, 977-986. https://doi.org/10.1056/NEJM199309303291401
 UK Prospective Diabetes Study (UKPDS) Group. (1998) Effect of Intensive Blood-Glucose Control with Metformin on Complications in Overweight Patients with Type 2 Diabetes (UKPDS 34). The Lancet, 352, 854-865. https://doi.org/10.1016/S0140-6736(98)07037-8
 Inzucchi, S.E., Bergenstal, R.M., Buse, J.B., et al. (2015) Management of Hyperglycemia in Type 2 Diabetes, 2015: A Patient-Centered Approach: Update to a Position Statement of the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care, 38, 140-149.
 Darmon, P., Bauduceau, B., Bordier, L., et al. (2017) For the Francophone Diabetes Society (SFD) Management of Hyperglycemia in Type 2 Diabetes: Position Statement of the Francophone Diabetes Society. Médecine des m aladies Métaboliques, 11, 577-593. https://doi.org/10.1016/S1957-2557(17)30139-6
 Balkau, B., Bouée, S., Avignon, A., et al. (2012) Type 2 Diabetes Treatment Intensification in General Practice in France in 2008-2009: The DIAttitude Study. Diabetes & Metabolism, 38, S29-S35. https://doi.org/10.1016/S1262-3636(12)71532-X
 Khunti, K., Wolden, M.L., Thorsted, B.L., et al. (2013) Clinical Inertia in People with Type 2 Diabetes: A Retrospective Cohort Study of More than 80,000 People. Diabetes Care, 36, 3411-3417. https://doi.org/10.2337/dc13-0331
 Pantalone, K.M., Wells, B.J., Chagin, K.M., et al. (2016) Intensification of Diabetes Therapy and Time until A1C Goal Attainment Among Patients with Newly Diagnosed Type 2 Diabetes Who Fail Metformin Monotherapy within a Large Integrated Health System. Diabetes Care, 39, 1527-1534. https://doi.org/10.2337/dc16-0227
 Kalafate, N., Aouiche, S., Khalfallah, A., et al. (2015) Therapeutic Inertia in Type 2 Diabetes: Finding the Culprits. Diabetes & Metabolism, 41, A124. https://doi.org/10.1016/S1262-3636(15)30471-7
 Ziemer, D.C., Miller, C.D., Rhee, M.K., et al. (2005) Clinical Inertia Contributes to Poor Diabetes Control in a Primary Care Setting. The Diabetes Educator, 31, 564-571. https://doi.org/10.1177/0145721705279050
 Camara, A., Baldé, N.M., Sobngwi-Tambekou, J., et al. (2014) Poor Glycemic Control in Type 2 Diabetes in the South of the Sahara: The Issue of Limited Access to an HbA1c Test. Diabetes Research and Clinical Practice, 108, 187-192.
 Makulo, J.R., Nseka, N.M., Lepira, F.B., et al. (2010) Correlation between Capillary Fasting Glucose and HbA1c: Study on 181 Type 2 Diabetic Patients in Democratic Republic of the Congo. Medecine Tropicale, 70, 513-516.
 Ntyonga-Pono, M.P. (2014) Adherence to Antidiabetic Treatment in the Gabonese Patient. L’observance du traitement antidiabétique chez le patient gabonais. Médecine des Maladies Métaboliques, 9, 198-202. https://doi.org/10.1016/S1957-2557(15)30043-2
 Douros, A., Dell’Aniello, S., Yu, O.H.Y., et al. (2018) Sulfonylureas as Second Line Drugs in Type 2 Diabetes and the Risk of Cardiovascular and Hypoglycaemic Events: Population Based Cohort Study. BMJ, 362, k2693. https://doi.org/10.1136/bmj.k2693
 Bieszk, N., Reynolds, S.L., Wei, W., et al. (2016) Act on Threes Paradigm for Treatment Intensification of Type 2 Diabetes in Managed Care: Results of a Randomized Controlled Study with an Educational Intervention Targeting Improved Glycemic Control. Journal of Managed Care & Specialty Pharmacy, 22, 1028-1038. https://doi.org/10.18553/jmcp.2016.22.9.1028
 Ferreira, D. and Maclean, G. (2018) Andragogy in the 21st Century: Applying the Assumptions of Adult Learning Online. Language Research Bulletin, 32, 11-19. https://www.researchgate.net/publication/323388304