Comorbidities

In Finland, a study found that the area-level socio-economic status has impact on diabetes care (diabetes process and outcome) in North Karelia region. The study included a total of 10,204 diabetes patients and the information of socioeconomic characteristics of participants were based on the postal code area level data. The study stated that lower level of socio economic status in the postal code area is related with poorer measurement activity of HbA1c among the type 2 diabetes patients. In addition, the study also found a positive correlation with higher education level and the achievement of recommended HbA1c level (Sikiö et al. 2014).

2.8 Comorbidities Definition

Different researchers have defined comorbidities in different ways. In 1970, Feinstein introduced the idea of comorbidity and defined it as “any clinically relevant phenomenon separate from the primary disease of interest that occurs while the patient is suffering from the primary disease, even if this secondary phenomenon does not qualify as a disease per se”.

Many authors argued that comorbidities are the presence of two or three diseases that are related with each other based on a common pathogenic mechanism, while multimorbidities are the simultaneous presence of two or more diseases that are not related to each other by a pathogenic mechanism. According to Valderas et al. (2009), comorbidity is the condition where one or more diseases appear in addition to an index disease. On the other hand, multimorbidities refer to existence of multiple diseases in one individual.

According to Jakovljević and Ostojić (2013), comorbidities commonly have three different meanings,

“1. Two or more medical conditions existing simultaneously, but independently with each other;

2. two or more medical conditions existing simultaneously and interdependently with each other what means that one medical condition causes, is caused, or is otherwise related to another condition in the same individual;

3. Two or more medical conditions existing simultaneously regardless of their causal relationship”.

Epidemiology

As the living standard and the health care are improving, the average life expectancy is also increasing. It is expected that the number of population having life expectancy in average of 60 years would be doubled by 2050. Bearing the cost of health care for older population has emerged as a new challenge. A huge burden of diseases also appears when we are dealing with aging population. Currently, single disease approach is not sufficient when we are treating multiple diseases as Salive (2013) estimated in his review study of multimorbidity among 31 million older persons in US. In Salive’s study, more than two thirds of all subjects had multimorbidity and the proportion increased with age.

Comorbidity is a global phenomenon. People with advanced age have more comorbidities. In USA, 75 million people have two or more concurrent chronic diseases spending 65% of the health care expenditure which is a very challenging situation for health care in US. 10 % of Americans have diabetes and 90 % of diabetes patients have two or more chronic diseases (Parekh & Barton 2010).

Chronic diseases are common with type 2 diabetes patients. Medical expenditure survey estimated that most of the adult diabetic patients have at least one chronic condition and 40%

have at least three. Nowadays diabetic patients receive good care, have good glycemic control and thus increased life expectancy which eventually give more chance to have other chronic diseases with advancing age (Piette & Kerr 2006).

Comorbidities and quality of type 2 diabetes care

Comorbidity or multimorbidity are often used to describe the coexistent multiple conditions in a patient. It has robust impact on health care utilization, financial resources and overall quality of health care as well. Quality of diabetes care also depend upon the number and the nature of the comorbidities. Many studies have found that quality of care varied by the nature of diseases,

number of diseases, number of visits to physicians and by some other socioeconomic factors as well (Piette & Kerr 2006, Zulman et al. 2014).

Effective management of diabetes is a great challenge, especially when diabetes patients come with one or more comorbid diseases. Both physicians and patients may escape or ignore diabetes related comorbid conditions and the management may focus only on acute conditions or dominant illnesses. It may lead to severe consequences of diabetes, lower the quality of care and increase the risk of mortality (Piette & Kerr 2006).

So far, many studies have been done to determine the impact of comorbidity on diabetes care in an individual and on the entire health system level. For instance, in a retrospective cohort study, Pentakota et al (2012) assessed the relationship between diabetes care and the type of comorbidity among the veterans. They examined the diabetes care by measuring number of visits per year, level of HbA1c and level of LDL cholesterol. Finally, they argued that diabetes patient with concordant illness (illness which overlaps with diabetes pathogenesis and management, for instance, cardiovascular diseases) have either similar or better quality of care regardless the number of visits. On the other hand, diabetes patients with discordant illness (for example, mental health illness) have poorer quality of care. Woodard et al. (2011) and Magnan et al. (2015a) found the similar impact of comorbidities on the diabetes care showing that diabetic patients with concordant diseases had better care and better achieved the recommended goal for controlling diabetes. They also found that diabetic patients with more chronic illnesses had better care. On the other hand, opposite association have also been observed in many studies. For example, Halanych et al (2007) studied the association of individual medical condition on diabetes care measured by Charlson Comorbidity Index (CCI). The authors reported that the rate of lipid and HbA1c tests reduced in the patient with higher number of comorbidities.

There are many reasons for unequal care of diabetes patient with comorbidity. Inadequate support and time limitation leads to non-optimal diabetes care and leads to poor outcomes. For example, in primary health care in US, patients with chronic diseases have been allocated more attention and time from physician for counseling and for making the management plan compared with some acute conditions (Ostbye et al. 2005).

Prioritizing the treatment goals in diabetic patients with comorbidities is not well documented among the physicians and patients. A systemic review suggested that high blood pressure is the most important factor predicting the adverse outcomes of type 2 diabetes but many physicians

may often ignore this when patients come with acute problem such as chronic pain (Vijan &

Hayward 2003). Sometimes, nature of diseases and onset of diseases causes the disparity in care of diabetes. Nam et al. (2011) reviewed literature about different barriers of diabetes management in patients and care providers. The authors argued that the patients’ self-care is overshadowed by urgent and prominent complaints like chronic pain, arthritis, asthma and heart diseases. In addition, 33% of diabetes patients are suffering from depression which is also a strong barrier for patients’ self-management and glycemic control.