Comorbidity

In order to facilitate research into the presence of more than one condition, several comorbidity data items were derived for the 2017-18 NHS using data from the ICD10-Classification.

The data items available are:

• Comorbidity (Self report) (including Diabetes, Kidney disease, Cardiovascular disease)
• Comorbidity (Self report) - Musculoskeletal
• Comorbidity (Self report) - Chronic Lower Respiratory
• Number of selected chronic condition groups

For each comorbidity data item, the following section outlines the:

• Definitions used to derive the data item
• Population applicable to the data item
• Methodology used to produce the data item.

For information on the ICD10 classifications, condition status and number of conditions reported (including current and long-term conditions), refer to the Health conditions section of this Users' Guide.

Population

The population for the comorbidity data items is all persons in the 2017-18 NHS and they are located on the selected person level.

Information about comorbidity was published in the National Health Survey: First Results, 2017-18.

Comorbidity (Self report)

Definition

This data item is produced for combinations of the following conditions:

• Diabetes
• Kidney disease
• Cardiovascular disease (CVD).

For the purposes of deriving this item the following definitions were used:

Diabetes

To be classified as having diabetes, the respondent needed to have been diagnosed with diabetes mellitus (type1, type2, type not known) regardless of their condition status.

For further information refer to the Diabetes and high sugar levels chapter of this Users' Guide.

Kidney disease

To be classified as having kidney disease the respondent needed to have been diagnosed with kidney disease and have reported that the condition is current. This condition is assumed to be long-term and is identified as having condition status of 1. Ever told has condition, still current and long-term.

For further information refer to the Kidney disease chapter of this Users' Guide.

Cardiovascular disease

To be classified as having cardiovascular disease (CVD), the respondent needed to have been diagnosed with one of the following conditions:

The following conditions were required to have been diagnosed and also current and long-term (condition status 1. Ever told has condition, still current and long-term):

• Hypertensive diseases
• Tachycardia
• Oedema
• Diseases of arteries, arterioles & capillaries
• Diseases of veins lymphatic vessels etc
• Other diseases of circulatory system
• Symptoms signs involving circulatory system

The following conditions only required diagnosis (condition status 1. Ever told has condition, still current and long-term, 2. Ever told has condition, still current but not long-term or 3. Ever told has condition, not current ):

• Ischaemic heart diseases
• Heart failure
• Other heart diseases
• Stroke
• Other Cerebrovascular diseases

For further information refer to the Heart and circulatory conditions chapter of this Users' Guide.

Methodology

Using the defined conditions, the following output categories were produced:

1. Diabetes only
2. Kidney disease only
3. CVD only
4. Diabetes and kidney disease only
5. Diabetes and CVD only
6. Kidney disease and CVD only
7. Diabetes and kidney disease and CVD
8. Does not have Diabetes or kidney disease or CVD
   

In this item each respondent is allocated to only one category.

In order to create some flexibility with the use of this item, categories 1 to 3 were produced, which contain persons with only one condition and also category 8 which contain persons with none of the conditions.

To produce frequencies based on different combinations of these conditions, users can collapse categories as required. For example, to determine those people with either Kidney Disease or CVD, combine categories 2,3,4,5,6,7. To determine those people who don't have CVD, combined categories 1,2,4 and 8.


Comorbidity (Self report) - Musculoskeletal

Definition

This data item is produced from 2017-18 NHS data for combinations of the following conditions:

• Arthritis
• Other musculoskeletal conditions.

For the purposes of deriving this item the following definitions were used:

Arthritis

To be classified as having arthritis, the respondent needed to have current and long-term Rheumatoid, Osteoarthritis or Other / type unknown Arthritis. These conditions are identified as having condition status of 1. Ever told has condition, still current and long-term or 4. Not known or not ever told, but condition current and long-term.

For further information refer to the Arthritis chapter of this Users' Guide.

Other musculoskeletal conditions

To be classified as having other musculoskeletal conditions, the respondent needed to have a current and long-term status (condition status 1 or 4) for one or more of the following conditions:

• Gout
• Other arthropathies
• Rheumatism
• Other soft tissue disorders
• Sciatica
• Disc disorders
• Back pain/problems nec
• Curvature of the spine
• Osteoporosis
• Other diseases of musculoskeletal system & connective tissue
• Symptoms, signs involving the musculoskeletal system & connective tissue.

For further information about other musculoskeletal conditions refer to the Arthritis, Osteoporosis and Other long-term conditions chapter of this Users' Guide.

Methodology

Using the defined conditions, the following output categories were produced:

1. Has arthritis only
2. Has other musculoskeletal conditions only
3. Has arthritis and at least one other musculoskeletal condition
4. Does not have arthritis or other musculoskeletal conditions

In this item each respondent is allocated to only one category.

In order to create some flexibility with the use of this item, categories 1 and 2 were produced, which contain persons with only one condition and also category 4 which contain persons who do not have a musculoskeletal condition.

Comobidity (Self report) - Respiratory

Definition

This data item is produced from 2017-18 NHS data for combinations of the following conditions:

• Asthma
• Other chronic lower respiratory disease.

For the purposes of deriving this item the following definitions were used:

Asthma

To be classified as having asthma, the respondent needed to have been diagnosed and the asthma to be current (has had symptoms in the last 12 months). This condition is identified as having condition status of 1. Ever told has condition, still current and long-term or 4. Not known or not ever told, but condition current and long-term.

For further information refer to the Asthma sub-section of this Users' Guide.

Other chronic lower respiratory disease

To be classified as having other chronic lower respiratory disease, the respondent needed to have been diagnosed with bronchitis or emphysema or they had not been diagnosed but considered their condition to be current and long-term. This condition is identified as having condition status of 1. Ever told has condition, still current and long-term, or, 2. Ever told has condition, still current but not long-term, or 3. Ever told has condition, not current or 4. Not known or not ever told, but condition current and long-term.

For further information about other chronic lower respiratory disease refer to the Other long-term conditions sub-section of this Users' Guide.

Methodology

Using the defined conditions, the following output categories were produced:

1. Has asthma only
2. Has other chronic lower respiratory disease only
3. Has asthma and at least one other chronic lower respiratory disease
4. Does not have asthma or other chronic lower respiratory diseases

In this item each respondent is allocated to only one category.

In order to create some flexibility with the use of this item, categories 1 and 2 were produced, which contain persons with only one condition and also category 4 which contain persons who do not have a respiratory condition.

Comparability with 2014-15

Comorbidity data are considered directly comparable between the 2017-18 and 2014-15 NHS.

More information regarding comparisons between 2014-15 NHS and previous cycles is available in the National Health Survey: Users' Guide, 2014-15 (cat. no. 4363.0).