Beneficios de la aplicación del MCC en la organización objeto de estudio

People with diabetes have higher risk of developing diabetic retinopathy if their level of blood glucose is high. Blood glucose levels are measured with the HbA1c test. HbA1c is a type of haemoglobin which holds the oxygen substance that is found in red blood cells and has glucose attached to it (NHS, 2012). The Diabetes Control and Complications Trial (DCCT, 1993) was a randomised controlled clinical trial conducted to assess the relationship between glycaemic control and the development and progression of early vascular complications in people with insulin dependent diabetes mellitus. The DCCT consisted of two similar studies: a primary prevention, which tested whether improvement of abnormal metabolic status led to prevention of the complications, and a secondary intervention study, where people with type 1 diabetes received intensive insulin therapy. Intensive treatment is the means to get glucose control to as near normal as possible. The primary outcome in the primary prevention was the first appearance and subsequent development of background diabetic retinopathy. In the secondary intervention study, the primary outcome was the development of pre-existent minimal retinopathy. The Diabetes Control and Complications Trial (DCCT, 1993) showed in the primary prevention cohort, that the intensive therapy reduced the adjustment mean risk for the development of retinopathy in insulin dependent diabetes mellitus by 76% (95 CI, 62 to 85%) as compared with conventional therapy. In the secondary intervention cohort, intensive therapy showed the progression of diabetic retinopathy by 54% (95 CI, 39-66%) and reduced the development of proliferative or severe non- proliferative diabetic retinopathy by 47% (95 CI, 14 to 67%). The United Kingdom Perspective Diabetes Study (UKPDS, 1998) found that intensive blood glucose control either by sulphonylureas or insulin substantially decreased the risk of microvascular complications, but not macrovascular disease in patients with type 2 diabetes. The Diabetes Control and

Complications Trial (Zhang et al., 2001) reported the progress (after 9-year

follow-up) of a study designed to determine whether improved glucose control in patients with newly diagnosed non-insulin dependent diabetes mellitus (NIDDM) is effective in reducing the incidence of clinical complications. Among the 153 patients within target metabolic control (mean HbA1c≤6.87%), 138 (90%) remained free of retinopathy. On the other hand, among the 166 patients

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within out of target metabolic control (mean HbA1c ≥9.49%), the complication did not develop in 71 (43%) and did develop in 95 (57%).

The Diabetes Control and Complications Trial confirmed that retinopathy develops in nearly 10% of patients with type 1 diabetes within target metabolic control, whereas more than 40% of patients with type 1 diabetes remain free of retinopathy despite out of target metabolic control. Whilst these findings confirm that HbA1c is the most significant risk factor for developing diabetic retinopathy that can be modified, the process of modifying HbA1c for people with diabetes, supported by Health Care Professionals, is far from straightforward.

Taking insulin and oral hypoglycaemic agents is the first line of treatment for lowering blood glucose. However, many studies reported that people with diabetes are generally not compliant with diabetes medication (Bailey, et al.,

2011, Karter, et al., 2010, Karter, et al., 2009). For example, Bailey and

colleagues (2011) found less than fifty per cent of people with diabetes adhere

to the prescribed diabetes medications (Bailey at al., 2011). Adherence to

prescribed medication is generally regarded as the proportion of patients taking at least 80% of their prescribed medication (Caro et al., 2004). A systematic review of adherence with oral hypoglycaemic medication reported that only between 61% and 85% of diabetes medications prescribed, are taken, whereas 25.5% level of non-adherence to insulin as people with diabetes never obtained a refill (Cramer, 2004). Adverse reactions and side effects can also lead to non- adherence. For example, some of the current treatments for diabetes are

associated with weight gain and hypoglycaemia (Yurgin et al., 2008; Donnelly

et al., 2008). The evidence suggests that resistance to diabetes medication is linked to many factors including the number of oral hypoglycaemic medications

(Thayer et al., 2010), the combination of insulin and oral hypoglycaemic

medication (Yurgin et al., 2008), age and perception of glycaemic control

(Donnelly et al., 2008), duration of the disease (Garcia-Perez, et al., 2013), side

effects (Curtis et al., 2009; Dilla et al., 2008; Donnelly et al., 2009), knowledge

(Boren et al., 2007), psychological burden (Garcia-Perez, et al., 2013),

complexity of dosing regimen (Garcia-Perez, et al., 2013), and

interactions/relationships with Health Care Providers (Ciechanowski et al.,

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is not straightforward. Diabetes self-management education and psychological intervention both aim to reduce blood glucose and yet systematic reviews of

both show only marginal gains in HbA1c (Royle et al., 2009; Allam et al 2009;

Ismail, Winkley, Rabe-Hesketh, 2004; Sturt et al., 2015). The evidence for

interventions to consistently modify (lower) blood glucose levels over the periods of time required to reduce diabetic retinopathy progression is low.

Whilst individual’s may wish to engage with the life style modifications necessary for the management of diabetes, the evidence suggests that it is often difficult to achieve these changes, particularly for those who live with a partner with high expressed emotion, or that people have periods of relapse (Lister et al., 2016). Therefore, it is important that the individual is supported during relapse and supported to understand that occasional outside of target diabetes control is inevitable with this complex metabolic condition and does not indicate permanent failure. Macaden and Clarke (2006) suggest that individuals can be supported to cope with relapses through a number of strategies such as providing relevant information, access to guidance when needed, and modifying health related behaviours through social support. According to Listers and colleagues (2014), greater consideration should be given to using family-based approaches rather than individual based approaches for diabetes management.