Scottish Health Survey 2014 - volume 1: main report

8 CARDIOVASCULAR CONDITIONS AND DIABETES

Shanna Christie

SUMMARY

Cardiovascular (CVD) conditions and diabetes

• In 2014, 16% of all adults aged 16 and over stated that they had ever been diagnosed with any CVD condition by a doctor, with prevalence higher for men than women. Prevalence for men increased from 15% in the 2003-2009 period to 18% in 2014, with much of this increase occurring between 2013 and 2014. In contrast, the figures for women have ranged from 14% to 16% across the years with no pattern (14% in 2014).
• Doctor-diagnosed diabetes prevalence was 6% for adults (8% for men and 5% for women) in 2014. Prevalence in men is significantly higher now (8%) than in 2003 (4%), with the biggest single increase occurring between 2013 (6%) and 2014 (8%).
• A fifth (20%) of adults in 2014 had any CVD condition or diabetes (23% of men, 17% of women).
• In 2014, 8% of all adults reported that they had ever been diagnosed with ischaemic heart disease (IHD) or stroke (10% of men, 7% of women).

Conditions and area deprivation

• Prevalence of any CVD was significantly higher in the most deprived areas (22%) than the least deprived areas (14%), using age-standardised data.
• Diabetes was twice as high in the most deprived (9%) than the least deprived (4%) quintile.
• IHD or stroke prevalence was also significantly higher among those in the most (14%) than the least deprived quintile (6%).

Family Risks

• A higher prevalence of diabetes was seen among those with a family history of type 1 or 2 diabetes (13%) than those with no family history of the condition (5%). This difference was particularly noticeable for men: 17% of men with a family history of the condition had been diagnosed with diabetes, compared with 6% of those with no family history.
• Prevalence of CVD among those with a family history of heart disease or stroke before the age of 60 was around twice as high as for those with no family history (25%, compared with 13%).
• Prevalence of IHD among this group was around three times as high as for those with no family history (12%, compared with 4%), while prevalence of stroke was around two times as high (5%, compared with 2%).

8.1 INTRODUCTION

Cardiovascular disease (CVD) is a general term describing diseases of the heart and blood vessels whereby blood flow to the heart, brain or body is restricted. It is one of the leading contributors to the global disease burden.^[1] Its main components are ischaemic heart disease (IHD) (or coronary heart disease) and stroke, both of which have been identified as clinical priorities for the NHS in Scotland.^[2] IHD is the second most common cause of death in Scotland after cancer, accounting for 13% of deaths in 2014, with a further 8% caused by stroke.^[3] Early mortality from heart disease and stroke have also both improved in recent years, but concern remains about continuing inequalities in relation to morbidity and mortality linked to these conditions.^[2],[4]

The increasing prevalence of diabetes, the most common metabolic disorder, is a major health issue for Scotland. Scotland has one of the highest levels of type 1 diabetes in Europe, but it is the increasing prevalence of type 2 diabetes - linked to obesity, physical inactivity and ageing - which is driving the increased prevalence and causing concern.^[5] Diabetes is a risk factor in premature mortality, although more effective treatments of diabetes and hypertension have offset some of the excess risk in recent years.^[5]

8.1.1 Policy background

One of the Scottish Government's National Performance Framework National Outcomes is for people in Scotland to 'live longer, healthier lives.'^[6] There is also a National Performance indicator to 'reduce premature mortality' (deaths from all causes in those aged under 75).^[7] CVD is described as one of the key 'big killer' diseases around which action must be taken if this target is to be met. In addition, a number of the National Indicators^[8] are linked to key CVD risk factors, most notably smoking,^[9] but also physical activity^[10] and obesity^[11] (the latter two are also major risk factors for diabetes).

In recognition of the challenges posed by long-term conditions such as CVD, diabetes and the respiratory conditions covered in Chapter 7 - both for the individual and their families, as well as for health and care services - the Scottish Government's over-arching strategy for long-term conditions was published in 2009. Delivering on a commitment made in the earlier Better Health, Better Care: Action Plan^,[12] the Action Plan recognised the need for system-wide action in response to the challenge presented by the increasing prevalence of long-term conditions within the context of an ageing population, the links to health inequalities, and the particular challenges of multi-morbidity - the presence of two or more long-term conditions. The Keep Well Programme^[13] focussed on delivering health improvements in deprived communities by offering health checks to individuals aged 40-64, including screening for CVD and its main risk factors.

The Heart Disease and Stroke Action Plan^[2]2 which was published in 2009, and the Diabetes Action Plan^[5]5, which was published in 2010, both set out a comprehensive programme for further reducing deaths and improving the lives of people living with heart disease, stroke and diabetes. This has been refreshed and separate Heart Disease^[14], Stroke^[15] and Diabetes^[16] Improvement Plans were published in August 2014 and November 2014. These set out key priorities for the delivery of improvements of treatment and care in heart disease, stroke and diabetes.

8.1.2 Reporting on CVD conditions and diabetes in the Scottish Health Survey (SHeS)

SHeS is an important source of information on the prevalence of CVD conditions and diabetes in Scotland. It also offers valuable information on the patterning of these conditions across different groups in society. In this chapter trends in self-reported CVD conditions and diabetes prevalence for adults are updated for 2014. Prevalence trends are also presented by area deprivation in Chapter 9.

New questions designed to measure the prevalence of diabetes among family members (to help estimate potential future disease risk) are also reported here for the first time since their introduction to the survey in 2012, alongside long-standing questions about heart disease and stroke in family members before the age of 60.

Supplementary tables providing additional data on these conditions are also available on the Scottish Government SHeS website.^[17]

8.2 METHODS AND DEFINITIONS

8.2.1 Methods

Participants were asked whether they had ever suffered from any of the following conditions: diabetes, angina, heart attack, stroke, heart murmur, irregular heart rhythm, or 'other heart trouble'. If they responded affirmatively to any of these conditions, participants were asked whether they had ever been told they had the condition by a doctor. For the purposes of the analysis presented in this chapter, participants were only classified as having a particular condition if they reported that the diagnosis had been confirmed by a doctor.

It is important to note that no attempt was made to verify these self-reported diagnoses objectively. It is therefore possible that some misclassification may have occurred because some participants may not have remembered (or not remembered correctly, or not known about) diagnoses made by their doctor.

8.2.2 Definitions

Any CVD condition

Participants were classified as having 'any CVD' if they reported ever having any of the following conditions confirmed by a doctor: angina, heart attack, stroke, heart murmur, abnormal heart rhythm, or 'other heart trouble'.^[18]

Diabetes

Participants were classified as having diabetes if they reported a confirmed doctor diagnosis. Women whose diabetes occurred only during pregnancy were excluded from the classification. No distinction was made between type 1 and type 2 diabetes in the interview.

Any CVD condition or diabetes

A summary measure of the above conditions is presented in the tables as 'any CVD condition or diabetes'.

Ischaemic heart disease (IHD)

Participants were classified as having IHD if they reported ever having angina or a heart attack confirmed by a doctor. All tables refer to ever having the condition.

Stroke

Participants were classified as having a stroke if they reported ever having had a stroke confirmed by a doctor.

IHD or stroke

A summary measure of the above conditions is presented in the tables as 'IHD or stroke'.

Diabetes, heart disease and stroke among family members

Participants were asked if any of their parents, children or siblings (living or dead) had ever had type 1 or 2 diabetes. Non-blood relatives were excluded from the definition (e.g. step-parents), though adopted people were asked to answer about their adoptive family if they didn't know their birth parents' diabetes status.

Family history of heart disease or stroke onset before the age of 60 was also measured. Participants were asked about their parents, siblings, aunts, uncles and cousins. The data on parents and siblings are presented in this chapter.

8.3 CARDIOVASCULAR CONDITIONS AND DIABETES

8.3.1 Trends in any CVD, diabetes, any CVD or diabetes, IHD, stroke, and IHD or stroke prevalence since 1995

Any CVD

In 2014, 16% of adults aged 16 and over reported that they had ever been diagnosed by a doctor with any CVD condition. While the latest figure does not differ significantly from 2013 (15%), and the longer trend from 2003 onward has seen only minor fluctuations, the patterns for men and women are different. Prevalence among men of any CVD increased from 15% in the 2003-2009 period, to 18% in 2014. In contrast, the figures for women have ranged from 14% to 16% across the years with no pattern, with the 2014 figure at the lower end of this (14%). Much of the increase in men occurred between 2013 and 2014, so this will need to be monitored in future years. Similar patterns can be observed for adults aged 16-64, although figures for men in 1995 and 1998 suggest the upward trend started earlier than 2003, albeit with a similar increase from 2013 to 2014 as seen for all adult men. Table 8.1

Doctor-diagnosed diabetes prevalence

About one in fifteen (6%) adults aged 16 and over in 2014 reported they had ever been diagnosed with diabetes by a doctor This is the same level as seen from 2011, but higher than the previously reported level of 4% in 2003. Prevalence has increased more among men than women. As with any CVD, prevalence of diabetes in men is significantly higher now (8%) than in 2003 (4%), with the biggest single increase occurring between 2013 (6%) and 2014 (8%). In contrast, while the latest figure for women (5%) is higher than in 2003 (4%), it has changed very little in the interim years. Figure 8A, Table 8.1

Any CVD or diabetes

The combined prevalence of any CVD or diabetes in adults aged 16 and over has increased over time, from 17% in 2003 to 20% in 2014, though the figures for the past three years have been very similar. As seen with the individual components of this measure, this increase over time was largely confined to men, among whom prevalence has risen from 17% in 2003 to 23% in 2014. The figures for adults aged 16-64 show similar patterns of increasing prevalence over time for men since the series began. Figure 8A, Table 8.1

IHD

In 2014, 6% of adults aged 16 and over had IHD, a similar level to that seen in most years since 2008. However, while the figures for men have seen little change over time, the most recent figures for women (5% in 2014) represent a downward trend, from 7% in 2003. Figures for women aged 16-64 demonstrate a generally downward trend in prevalence of IHD since 1995. Figure 8A, Table 8.1

Stroke

Prevalence of ever having had a stroke, among adults aged 16 and over in 2014, was 3% compared with 2% in 2003. This is the first time there has been a statistically significant difference in prevalence since it was first estimated in 2003. Prevalence has increased for both men (2% in 2003, 3% in 2014) and women (2% in 2003, 3% in 2014), although only the change for women is significant. Figure 8A, Table 8.1

IHD or stroke

The combined prevalence of IHD or stroke in adults aged 16 and over was 8% in 2014 and has been almost identical in all years since 2003. The figures for those aged 16-64 since 1995 were similarly static (around 4%). Table 8.1

8.3.2 Any CVD, diabetes, any CVD or diabetes, IHD, stroke, and IHD or stroke prevalence in 2014, by age and sex

Any CVD

In 2014, 16% of adults aged 16 and over reported any CVD condition. Prevalence increased with age, from 5% among those aged 16-24 to 42% for those aged 75 and over. A significantly higher prevalence was reported by men (18%) than by women (14%). This differs from previous years, and is due to the recent increase in prevalence among men (reported in Section 8.3.1).

Prevalence increased by age in both men and women, from 5% of those aged 16-24 to 49% of those aged 75 and over among men, and from 5% to 37% among women. Prevalence was higher among men than women in all age groups. Table 8.2

Doctor-diagnosed diabetes

In 2014, overall prevalence of doctor-diagnosed diabetes was around one in fifteen (6%) for adults aged 16 and over, with marked variation by age group from 1% for those aged 16-24 to 15% for those aged 65 and over. Men had a higher prevalence than women for each age group, with the exception of those aged 16-24 (men 1%, women 2%). Prevalence increased steadily with age among men, whereas the pattern was fairly flat for women aged 16-44 (1-2%) before increasing to 12% for those aged 65 and over. Figure 8B, Table 8.2

Any CVD or diabetes

A fifth (20%) of adults in 2014 had a CVD condition or diabetes (23% of men and 17% of women). Prevalence was lower among younger adults (6-16%), but reached 27% in the 55-64 age group and increased to 48% for those aged 75 and over. Figure 8B,Table 8.2

IHD

IHD was reported by 6% of adults aged 16 and over in 2014. Prevalence was very low among the 16-44 age group (1% or less), rising to 4% for those aged 45-54, with higher levels seen in the oldest age group (21% for those aged 75 and over). From the age of 35 onwards, men had higher prevalence than women for all age groups. Figure 8B, Table 8.2

Stroke

Prevalence of stroke was low, overall, at 3% in 2014. As with IHD, stroke was rare in those aged under 45 (less than 1%). Prevalence increased gradually with age from 2% of those aged 45-54 to 11% for those aged 75 and over. Men and women tended to have similar levels of prevalence throughout the age ranges, with those aged 75 and over being the only group where more than one in ten reported having had a stroke (13% of men, 10% of women). Figure 8B, Table 8.2

IHD or stroke

The combined prevalence of IHD or stroke was 8% in 2014 (10% in men, 7% in women). Similar to the patterns for the individual conditions, prevalence increased progressively with age from 5% in the 45-54 age group to 30% in those aged 75 and over. The difference between the rates for men and women were particularly pronounced in those aged 55-64 (19% men, 8% women) and 75 and over (35% men, 26% women). Table 8.2

8.3.3 Any CVD, diabetes, any CVD or diabetes, IHD, stroke and IHD or stroke in 2014, by area deprivation and sex

The age-standardised prevalence of all the CVD conditions presented in Table 8.3 was significantly higher in 2014 for adults living in more deprived areas in Scotland than in less deprived areas. Prevalence of IHD was almost three times higher among people living in the most deprived quintile (11%) than in the least deprived quintile (4%). Doctor-diagnosed diabetes prevalence more than doubled between the least and most deprived quintiles (from 4% to 9%), while any CVD prevalence increased from 14% to 22%. There was less of a clear pattern for stroke prevalence, but levels were lowest in the two least deprived quintiles (2%) and highest in the two most deprived quintiles (4%). Following these patterns, the combined measure of any CVD or diabetes showed higher levels in the most deprived areas (27%) compared with the least (17%), and the same was true for IHD or stroke (14% in the most, 6% in the least deprived areas).

The overall patterns described above were generally the same for men and women separately. The main points of divergence were that men's prevalence of IHD increased more sharply with deprivation than women's did (in both relative and absolute terms), while the relative increase in women's diabetes prevalence between the least and most deprived areas was higher than it was for men's (though the absolute difference was similar). Figure 8C, Figure 8D, Table 8.3

8.4 FAMILY-BASED RISK FACTORS FOR HEART DISEASE, STROKE AND DIABETES

Table 8.4 compares the prevalence of doctor-diagnosed diabetes in adults in 2014, among those with a family history of type 1 or 2 diabetes and those with no reported family history. Prevalence of doctor-diagnosed diabetes was 13% for those with a family history of the disease and 5% for those without. This higher prevalence of diabetes among people with a family history was seen among men (17% with a family history, 6% without) and women (9% and 4% respectively), though the relative and absolute difference was somewhat greater among men. Figure 8E, Table 8.4

Table 8.5 presents a similar analysis, but looks at prevalence of any CVD, IHD or stroke in adults in 2014 among those with and without a family history of heart disease or stroke before the age of 60. There was a higher prevalence among those with a family history of disease than those without for any CVD (with family history 25%, without 13%), IHD (with 12%, without 4%) and stroke (with 5%, without 2%). These patterns were found among both men and women. Figure 8F, Table 8.5