El tratamiento psicológico desde la perspectiva conductual

This section presents a review of the published literature on burden of GDM. The burden of GDM can be categorised into both health and financial aspects. The major health burden of GDM is the prevalence of maternal and infant morbidity. On the other hand, the financial burden is very much the cost of screening and treatments in order to complete full diagnostic and medical procedures required for both the mother and infant.

4.4.1 Health burden

Reports from many sources indicate that type 2 DM is increasing rapidly throughout developed and developing countries. For example, Hilary King and co-workers have carefully analysed a number of reports and published their findings, in which adjustments for age were included, to develop the most comprehensive estimates of the prevalence of diabetes (King et al., 1998). In the same study, predictions were made of the numbers of people with diabetes who would be aged 20 years or more in three different time periods, 1995, 2000 and 2025. Worldwide, the prevalence of diabetes in adults was estimated to be 4.0% of the population (135 million adults) in 1995 and it is estimated that in 2025 the prevalence of diabetic adults will increase to 5.4% of the population (300 million adults) In 2004, the revised projections of the prevalence of diabetes for year 2000 and 2030 were published by Wild and colleagues. The prevalence of diabetes for all age groups worldwide in 2000 and 2030 was estimated at

2.8% and 4.4% respectively. The total number of people with diabetes is predicted to increase from 171 million in 2000 to 366 million by 2030 (Wild et al., 2004). Moreover, Type 2 diabetes and obesity are frequently diagnosed in children and young adults in many countries. In the UK, 2.6 million people have been diagnosed with diabetes mellitus in 2009. The prevalence of diabetes in adults across the UK varies, from 5.1 % in England, 4.5 % in Northern Ireland, 4.6 % in Wales and 3.9 % in Scotland (Diabetes UK, 2010).

The global increase in incidence of diabetes has been accompanied by an increase in incidence of GDM in many countries. There are differences in the results of prevalence studies. The prevalence of women with GDM has increased over time, affecting between 1%-16% of women, depending on the diagnostic criteria and population studies (King, 1998). A recent international survey of 47 countries estimated a prevalence range of <1% - 28%, with data derived from expert analysis and national prevalence estimates (Jiwani et al., 2012). Moreover, GDM has been found to be more prevalent in African Americans, Hispanic/Latino and American Indians (National Institute of Diabetes and Digestive and Kidney Diseases, 2008). The prevalence is often significantly different in populations of different size and diversity, reflecting differences in geographic diversity (states, regions, and countries) and the definition used to identify women with GDM. The magnitude of the risk varied in different ethnic groups, ranging from 9% in Caucasians, 11.9% in Latinos, and 25% in women of Mediterranean or east-Asian descent (Berger et al., 2002). Moreover, approximately 650,000 women give birth in England and Wales each year, and 2-5% of them have diabetes (NICE, 2008b). As mentioned above, the prevalence of GDM has not yet been fully quantified. Additionally, the prevalence of pregnancy with GDM has increased over time. This study therefore conducted a comprehensive systematic review to assess the prevalence of GDM and is presented in chapter 5.

Increased maternal morbidity because of GDM may occur during pregnancy or in the longer term (Barry and Gabbe, 1998). In many studies, an increased risk was reported for preeclampsia, polyhydramnios, and cesarean section in women with GDM (Sermer et al., 1995) (de Veciana et al., 1995). Despite the fact that GDM occurs during pregnancy, a relatively short period of time in a woman’s life, it may cause type 2 DM in the long term. Postpartum, women with GDM have a significantly increased risk of type 2 diabetes. The National Institute of diabetes and digestive and kidney disease in 2008 stated that the risk of developing diabetes in women with GDM was about 5-10%, and that the risk slightly increased at 40%-60% in the next 5 to 10 years. Coustan and colleagues studied former gestational diabetic women, and found diabetes or impaired glucose tolerance (IGT) in 6% at 0–2 years, 13% at 3-4 years, 15% at 5-6 years, and

30% at 7-10 years postpartum (Coustan et al., 1993). In the case of postpartum impaired glucose tolerance and high body mass index (BMI) in adult females, they are predicted to develop type 2 diabetes after GDM occurrence.

Previous estimates of perinatal mortality have been based on results of older studies. Evidence to support increases in perinatal mortality related to GDM was confirmed in a more recent literature review of these older studies (Martine et al., 2007).

Perinatal mortality rates of 49-198 per 1,000 births have been observed to occur in women receiving GDM treatments (Coustan and Lewis, 1978). The perinatal mortality rate in infants of diabetic mothers has declined sharply from 250 per 1,000 live births in 1960 to a near-normal 20 per 1,000 live births in 1980 (Weintrob et al., 1996). Infants born to diabetic mothers have a risk of perinatal morbidity and mortality, resulting from hyperbilirubinemia, macrosomia, birth trauma, hypoglycaemia and neonatal respiratory distress syndrome (Crowther et al., 2005).

In terms of health-related quality of life (HRQoL) in women with GDM, there have been only a few studies that have investigated the effects of GDM on women’s HRQoL.

A randomised control trial (RCT) in Australia measured maternal health status by the Short-Form 36 (SF-36) at 6 weeks and 3 months postpartum, and stated that treatment of GDM improved the mother’s HRQoL (Crowther et al., 2005). The results of Crowther and colleagues were used to estimate QALY in a cost-effectiveness analysis for GDM in the UK (Round et al., 2011). In Finland, the HRQoL after pregnancy of 100 women sampled from the birth register at a University hospital was measured using the 15D instrument. This study showed insignificant difference in the median and mean level values of 15D between the GDM group and the control group (Halkoaho et al., 2010). In addition, another report showed that Type 2 DM after GDM may reduce life expectancy up to 10 years on average (Diabetes UK, 2012). No studies have been conducted in terms of Disability adjusted life years (DALY) for GDM yet. However, two cost-effectiveness analysis (CEA) studies for GDM screening tests reported results in terms of DALY Adverse in order to present the long term adverse complications for mothers who have both GDM and type 2 DM (Lohse et al., 2011) (Marseille et al., 2013).

4.4.2 Financial burden

It is estimated that 10% of the entire National Health Service budget is accounted for by diabetes, approximately £9 billion a year (based on the 2007/2008 budget for the NHS) (Diabetes UK, 2010). GDM management involves initial screening and diagnostic tests, treatments (dietary therapy, self-monitoring blood glucose level, pharmacotherapy and insulin programme), management of maternal medical complications (maternal trauma,

preeclampsia and operative deliveries), monitoring blood glucose level (pharmacotherapy and insulin programme), and management of neonatal complications (macrosomia, brachial plexus injury (BPI), jaundice and birth trauma). All of these account for parts of the financial budget.

In the UK, the NHS reported national costs for antenatal care and diabetes in pregnancy in 2008 (NICE, 2008a). The cost of a random blood test was £3.37 and the cost of a diagnostic test by 75g oral glucose tolerance test was £17.58. It was estimated that the net costs of screening and testing for GDM in England were £2,150,000 per year, which included all pregnant women with risk factors tested by the biochemical test and diagnostic test. The estimated costs of treatment of blood glucose monitoring, oral medication and regular insulin or analogue insulin were £704,000, £4,000 and £55,000 respectively. The costs of implementation of treatment for GDM by year 1, 2 and 3 in England were estimated at £840,000, £897,000 and £953,000, respectively (National Health Service, 2008b). In 2007, Chen and colleagues estimated the national medical costs associated with GDM by analysing National Hospital Discharge data in the USA.

They showed that the total estimated cost attributable to GDM nationally was $596 million (approximately $3,305 per woman with GDM) for mothers, $40 million for newborn babies (approximately $209 per newborn of mothers with GDM), and $320 million for medical care costs (Chen et al., 2009). Maternal GDM can be managed in various ways. Approximately 65% (cost £114.82 per course/person) of the cases will undergo dietary therapy with constant monitoring of blood glucose levels, approximately 20% (cost £3.09 per course/person) will receive oral hypoglycaemia therapy, and approximately 15% (cost £59.57 per course/person) will be treated with insulin (National health service, 2008a). In 2007, The University Hospitals of Coventry and Warwickshire estimated that the cost of each case of OGTT to the NHS was £12.13 (Wilson et al., 2008).

4.5 Adverse complications of GDM for mother and