Psychiatric Morbidity

Tables 3.10, 3.11 and 3.12 provide statistical information on psychiatric morbidity among the UK Armed Forces. They summarise all new referrals of Armed Forces personnel to the MOD's Departments of Community Mental Health (DCMHs) for outpatient care. DCMHs are specialised psychiatric services based on community mental health teams, closely located with primary care services at sites in the UK and abroad.

DCMH staff record the initial psychiatric assessment during a patient’s first appointment, based on presenting complaints. The information is provisional and final diagnoses may differ as some patients do not present the full range of symptoms, signs or clinical history during their first appointment. Individuals may be seen at a DCMH, e.g. for counselling, who do not have a mental disorder. The psychiatric assessment data were categorised into three standard groupings of common mental disorders used by the World Health Organisation’s International Statistical Classification of Diseases and Health-Related Disorders 10th edition (ICD-10).

A rigid pseudo-anonymisation process, and other measures preserving patient confidentiality, has enabled full verification and validation of the DCMH returns, importantly allowing identification of repeat attendances. It also ensured linkage with deployment databases was possible, so that potential effects of deployment could be measured.

Deployment data, used for deployment breakdowns and to calculate denominators, cover several operational deployments between November 2001 and December 2008, although person level deployment data for Afghanistan between 1 January 2003 and 14 October 2005 were not available. About 4% of the deployment records were not successfully validated against the “gold standard” personnel records held by the Service Personnel and Veterans Agency. Deployment markers were assigned using the criteria that an individual was recorded as being deployed to the Iraq and/or Afghanistan theatres of operation if they had deployed to these theatres prior to their appointment date. To be accurate, these tables compare those who had been deployed before their first appointment with those who have not been identified as having deployed before their first appointment.

The data are presented as numbers, rates and confidence intervals for those rates. The rates presented in this section relate to the whole population, rather than a sample. However, even in a population there is still random variation in the observed number of cases in a particular time period (particularly for rare events such as suicide). Confidence intervals are useful in making inferences about whether observed differences (e.g. between two time periods or two subgroups of the population) are significant or are likely to be due to chance alone.

In order to calculate rates, an estimate of person time at risk is required for the denominator value. The estimate was calculated using a 13-month average of strengths figures (e.g. the strength at the first of every month between January 2008 and January 2009 divided by 13 for 2008 strengths). Strengths figures include regulars, Gurkhas, Military Provost Guard Staff, mobilised reservists, Full Time Reserve Service personnel and Non-regular Permanent Staff, as all of these individuals are eligible for assessment at a DCMH.

95% Confidence Intervals (CIs) are calculated based on the Normal Distribution where there were more than 29 cases, and the Poisson Distribution where there were 29 or fewer cases. CIs provide the range of values within which we expect to find the real value of the indicator under consideration, with a probability of 95%. If the confidence intervals of two rates do not contain any common values, these figures are statistically significantly different.

Interpretation of these figures requires caution. They do not cover the full picture of all mental disorders in the UK Armed Forces. Referral to a DCMH is obtained via the individual's GP. Personnel may have been seen in Primary care, who did not require, or who did not wish, onward referral to the DCMH. Information on patients only seen in the primary care system is not currently available. It is also possible that the support through a strong culture of comradeship within the Armed Forces, may have served to minimise the number and severity of symptoms experienced by some cases. It is important therefore to view the results presented here alongside independent academic research, such as that conducted by the Kings Centre for Military Health Research, who collect subjective information on self-reported mental health, through the use of confidential surveys.

Further analysis can be found in the UK Armed Forces Psychiatric Morbidity reports, which are published on the DASA website.