Mental health problems associated with pregnancy and childbirth affect between 10 and 20% of women, and can have devastating impacts on women and their families. There is good evidence for effective treatments, but about half of all cases go undetected. Even where they are, only 15% in the UK have access to the full level of care recommended by bodies like NICE. Many areas provide no specialist services at all.

Sometimes the most compelling cases for extending the provision of care include financial and economic arguments. In a recent report for the Maternal Mental Health Alliance by the Centre for Mental Health and the PSSRU, Bauer et al (2014) present the societal economic costs of perinatal mental illness in the UK. The grand total estimate is over £8 billion. But should we believe it?

Methods

In this study, ‘perinatal’ is taken to refer to the time including pregnancy and the first year after childbirth. It extends beyond the common focus on postnatal depression, incorporating anxiety and psychosis. The cost of conditions such as eating disorder, stress, PTSD, OCD and personality disorder are not estimated due to lack of data.

The study comprised 2 stages: literature review and economic modelling. I’ve delved into the online appendices to try and get a clearer picture.

Literature review

The search tried to identify studies:

1. Measuring resource use or costs
2. Capturing health and wellbeing outcomes and
3. Reviewing the prevalence and natural course of illness.

The authors searched various databases including PsycINFO, CINAHL and Global Health. The search included a broad set of terms. However, details of the search strategy are not provided.

Economic modelling

The aim here is to combine data found in the literature review, but the methods used are unclear. Probabilities of adverse events were used to predict pathways for women and exposed groups (children and partners). Costs were measured in 2012/13 prices and were attached to these adverse consequences. These costs included use of public services, losses of quality adjusted life years (QALYs) and productivity losses. Service use was costed using the usual sources, such as the Unit Costs of Health and Social Care (Curtis 2013). QALYs were valued at £25,000. Suicide and infanticide was valued at £1,722,000; the current ‘value of a prevented fatality’ used by central government. Costs were estimated from both an overall societal perspective as well as from a public sector services perspective (including health and social care, education and criminal justice).

Results

The cost per case was estimated for 3 conditions, as shown in the table below:

These figures include impact on both mother and children. For children, a broad range of factors were accounted for including pre-term birth, emotional problems, conduct problems and special educational needs.

Based on the prevalence of each condition, and 813,000 births in the UK in 2012, the total societal cost is estimated to be £8.1 billion per one-year cohort of births. This represents about £10,000 per birth in the UK. 73% of this cost relates to long-term adverse impacts on the child rather than the mother. The authors found that the average cost to society of a single case of perinatal depression is around £74,000, of which £51,000 relates to impacts on the child.

It is estimated that the cost of bringing services up to guidance standards would be around £280 million; £400 per birth. Given that the cost to society is estimated as £10,000 per birth (with £2,100 falling on the public sector), the return on investment seems obvious.

Discussion

This report is important, as it is the first serious attempt to estimate the costs to society of perinatal mental health problems. However, the estimated societal costs (as currently presented) are unconvincing. The main reason for this is that the methodology is not clear; almost no explanation of how the data were combined is provided. Furthermore, the authors’ literature review was not reported systematically. As such, we cannot be sure whether or not there is bias in the figures that are used. Hopefully a fully peer-reviewed version of this study will be published in due course to address this.

Depression and anxiety have a much higher prevalence than psychosis, and for each of these the greatest cost per case relates to QALY losses. For perinatal depression it represents more than half of the cost. One QALY represents the value of living in full health for one year, so this part of the sum involves attaching a monetary value to health. Economists have spent a long time trying (and failing) to figure out what this value should be. The authors use £25,000 as a societal value for a QALY. However, the very idea of a societal value for a QALY has been described as a myth (Brouwer et al, 2008). It may be more useful to consider the observable value of a QALY based on current expenditure and outcomes in the NHS; about £18,000 (Claxton et al, 2013). It is of concern that such a controversial figure dominates the estimates. In fact, most people do not think about health outcomes as a cost at all. A conservative approach would not include these ‘health costs’.

The figures relating to public sector costs are probably more robust (notwithstanding methodological opacity), and the parameters used seem reasonable. These are estimated to be about £1.7 billion in total.

To answer the question posed in the title: no, perinatal mental health problems do not cost the UK £8 billion. At least, not in the way we normally think about costs. The total cost of £8.1 billion is presented as ‘shocking’. While that may be so, it should be considered alongside similarly astronomic estimates of the costs of personality disorder (Sampson, 2014b), bipolar disorder (Sampson, 2014a) and other conditions.

Public sector costs are estimated to be more than £2,000 per birth in the UK, while the cost of providing appropriate care is estimated to be around £400. Even handling these figures with caution, it is not unreasonable to conclude that current levels of investment in services for perinatal mental health problems (as for mental health care generally) are likely to be grossly inefficient.

Links

Bauer A, Parsonage M, Knapp M, Iemmi V, Adelaja B. Costs of Perinatal Mental Health Problems. London School of Economics and Political Science, 2014.

Brouwer W, van Exel J, Baker R, Donaldson C. The New Myth: The Social Value of the QALY. PharmacoEconomics 2008; 26(1):1–4. [PubMed] [RePEc]

Sampson C. Are Treatments for Bipolar Disorder Cost-Effective? The Mental Elf 2014a

Sampson C. Are Treatments for Borderline Personality Disorder Cost-Effective? The Mental Elf 2014b

Claxton K, Martin S, Soares M, Rice N, Spackman E, Hinde S, Devlin N, Smith PC, Sculpher M. Methods for the Estimation of the NICE Cost Effectiveness Threshold. CHE Research Paper 81. 2013 [RePEc]

Curtis L. Unit Costs of Health & Social Care 2013. 2013