Parents with alcohol and drug problems: using case studies to estimate the cost-benefit of interventions

Published 10 May 2021

Applies to England

1. Introduction

This guidance supports local areas, organisations and providers that have collected, or intend to collect, case studies to estimate how much social and economic cost they can avoid by supporting families experiencing alcohol and drug problems.

It also shows you how to use Public Health England’s (PHE) Parents with alcohol and drug problems: Investing in families workbook.

The Excel workbook is made up of 3 parts:

  • the social cost-benefit tool which contains a template you can use to estimate the costs in your case study and 4 worked examples
  • the unit cost database contains the direct, indirect and intangible costs for each cost theme in 2020 to 2021 prices
  • annexes contain HM Treasury’s gross domestic product (GDP) deflator, HM Treasury’s discount factors and market forces for reference

This guidance presents a worked-through example of a case study to estimate the cost-benefit of supporting families experiencing problem parental alcohol and drug use.

2. Using case studies

Case studies are a type of descriptive qualitative research typically used to gather information about an individual or a small group of people (like a family) receiving an intervention. You can then use this information to draw conclusions about the effect of the intervention in that specific context.

Using a case study approach can help you understand how and why different events and interventions might affect a family. This can provide a powerful story that can help when making a case for continuing to provide services. Compared with full-scale evaluations, case studies can be a more achievable, less resource-intensive way for commissioners and providers to show the effects of an intervention.

It is important to remember when you use case studies that the estimated costs represent potential benefits specific to that family and not the average benefits of the intervention. To estimate the latter, you would need to collect data on every family receiving the intervention.

3. Collecting case studies

When exploring the effects of an intervention, it is important to understand family dynamics and experiences before, during and after the intervention. This helps you to understand how things have changed for the family.

There are many ways to collate this type of data in a case study, and you might have your own preferred way to do so. You can download a case study template to use as an example or fill in with your own information.

Evidence of an intervention’s effects is stronger when the information comes from a variety of sources, such as an adult alcohol and drug worker, a schoolteacher and a child social worker. The family’s own experiences are an important component but should be validated using other sources.

4. Types of cost

There are 3 types of costs in the unit cost database:

  • direct costs which are estimated monetary costs that directly relate to providing treatment and support – for example, costs to the local authority, NHS or criminal justice system
  • indirect costs which are generally related to productivity losses from people being ill or dying prematurely
  • intangible costs which represent disease burden, meaning the effect a condition has on someone’s quality of life and how long they will live – this is quantified as quality-adjusted life years (QALYs) and valued at £60,000 per QALY

Economic evaluations typically include wider indirect and intangible costs. Where available, we have also presented these so you can use them to estimate wider social and economic costs.

You can find more information on how to appraise and evaluate policies, projects and programmes in HM Treasury’s Green Book.

All costs have been inflated using HM Treasury’s latest gross domestic product (GDP) deflator and will be updated annually. Costs are rounded to emphasise that they are estimates.

The database presents most costs as annual costs. It also presents lifetime costs where these exist, along with methodological explanations such as how many years make up the ‘lifetime’. We have included references for the sources of all costs with links to the publication and an explanation of calculations and limitations.

Table 1. Examples of cost breakdown

Cost theme Direct costs Indirect costs Intangible costs
Social care All costs are direct Not applicable Not applicable
Kinship care Not applicable Lost employment opportunities from having to look after children Not applicable
Education Providing alternative education following exclusion Loss of future earnings following exclusion Not applicable
Health Medical and ambulance services Prescriptions Specialist treatment for alcohol and drug use Not applicable QALY losses
Crime Police and prison costs Insurance costs QALY losses from being a victim of crime

5. Example case study

Below is a real case study, although the name has been changed. A drug and alcohol treatment provider collected the information to show how effective their service is. It tells the story of a vulnerable woman with a long history of substance misuse who seeks treatment when she discovers she is pregnant.

We will use the case study as an example of how you can use the unit cost database to estimate costs that could be avoided in the future.

Case study: Sarah

Sarah sought support to overcome her 20-year history of alcohol and cannabis use when she was 2 weeks pregnant. As well as a long history of using drugs and alcohol and a physical dependence on alcohol, Sarah had additional support needs related to depression, anxiety and childhood trauma. Sarah lived in unsuitable accommodation and was at risk of homelessness.

She received regular one-to-one psychosocial support from a family worker before entering a residential service for detox and rehabilitation. She and the father of her baby also received joint support to address interparental conflict.

Sarah gave birth at the beginning of May 2020. She is abstinent from all substances and both Sarah and her baby are doing well. Sarah and the father of her baby are no longer in a romantic relationship but are regularly communicating. She registered as homeless with a plan to move into appropriate accommodation, which will support her recovery.

Step 1: Open the social cost-benefit tool and select appropriate cost themes

Table 2 shows the different cost themes and explains when it might be appropriate to consider including certain activities, behaviours and events in a case study.

When using a case study to estimate social cost-benefit, we advise you to note the number of children or adults affected for each relevant cost theme.

Table 2: Cost themes

Cost theme When it might be appropriate to consider
Early help (family hubs) and child social care When a child is or was receiving, or it is highly probable that they would have received, statutory (for example child protection and child in need plans) and non-statutory (for example family hubs support, Troubled Families) support from children and family services.
Young person adopting carer role When a young person in the family, for example, an elder sibling, is taking on or would have taken on carer responsibilities for younger siblings or their parents.
Kinship care When a child is, was or is likely to be living with grandparents, other family members or connected adults.
Exclusion from school Instances where a child is either permanently or temporarily removed from school (up to 45 school days in one school year) or at significant risk of being excluded.
Truancy Instances where a child does not attend school or leaves school early without permission or a legitimate reason.
Perinatal depression and anxiety Cases when a mother is experiencing or has experienced depression and anxiety during pregnancy or up to one year after the birth of a child.
Conduct disorder According to National Institute for Health and Care Excellence (NICE) guidance on antisocial behaviour, conduct disorder refers to “a persistent (several months or longer) pattern of antisocial behaviour where a child or young person repeatedly carries out aggressive acts that may cause them distress and/or social impairment, and upset other people”.
Foetal alcohol spectrum disorder When it is highly probable that a mother would have been drinking problematically throughout pregnancy were it not for intervention.
Homelessness When a family was homeless, or at risk of homelessness. Homelessness refers to rough sleeping, the statutory homeless and the hidden homeless (such as those in hostels, bed and breakfasts, squats or sleeping on the floors or sofas of friends and family). At risk of homelessness could include, but is not limited to, people living with significant financial pressures or escaping a violent relationship.
NHS treatment Cases of NHS treatment for physical and mental health problems and events, such as attending A&E.
Alcohol or drug treatment Where a member of the family is or was receiving specialist treatment for alcohol or drug dependency. Note: unit costs are for adults but could be used for children and young people receiving treatment as a proxy.
Domestic abuse When there is evidence of domestic abuse in the family before an intervention. Domestic abuse includes physical violence, coercive control and ‘gaslighting’ or other psychological abuse, economic abuse, online abuse, threats and intimidation, emotional abuse and sexual abuse. Note: current costs exist for adult victims only.
Crime Instances of crimes committed, irrespective of whether the offender was arrested for the crime. Not all unit costs of crime are included in the database, just the most common crimes committed by people with problem alcohol and drug use.

Of course, the above list is not exhaustive. If there are other known costs that would be helpful to include that are not mentioned above, please let us know via PHE’s parental alcohol and drug use group (login needed).

The database is an iterative product which we will update and improved as new evidence comes to light.

The information from table 2 has been integrated into the social cost-benefit tool. Figure 1 is a screenshot from a worked example included in the tool. It shows how hovering above a cost theme displays a note explaining when the cost might be appropriate to consider.

Figure 1. Cost theme checklist from the social cost-benefit tool

The cost theme list is split into social benefits and costs. Social benefits are the positive outcomes that are measured following an intervention (for example a child no longer being on a child protection plan). Costs refer to the cost of treatment and any ongoing support from early help or social care.

The cost themes included in Sarah’s case study are:

  • child protection plan
  • perinatal depression and anxiety
  • no risk of foetal alcohol spectrum disorder (FASD)
  • homelessness
  • specialist treatment (community and residential)

Perinatal depression and anxiety: by addressing Sarah’s mental health issues now, it is likely that the lifetime costs will be greatly reduced, if not avoided altogether. However, as the amount of cost avoided is not clear, we will not include the costs avoided by managing her mental health. It is reasonable to assume that the costs associated with Sarah’s child resulting from her perinatal depression and anxiety could be avoided if Sarah’s recovery is sustained and her mental health issues are managed.

No risk of FASD: continued problematic drinking during pregnancy would have put Sarah’s baby at risk of FASD, which could result in growth impairments, developmental delays, intellectual disability and conduct disorders. All of these are associated with substantial costs to society.

Figure 2 shows a screenshot from the worked example of Sarah’s case study in the social cost-benefit tool. In this example, we found the cost themes relating to Sarah and her baby and placed a ‘1’ in the relevant yellow cells under ‘No. of children’ and ‘No. of adults’. The table then automatically populated with the relevant costs, using the latest prices contained in the unit cost database.

Figure 2. Adding number of people in case study affected

You can overwrite costs in this table to input your own costs. Figure 3 shows another screenshot from the worked example of Sarah’s case study in the social cost-benefit tool. Here cost cells with a red triangle in the top right-hand corner contain information about the cost, which is displayed by hovering above the cell.

Figure 3. Cost information

Step 2: Avoiding double counting

Avoiding double counting is the most important step of the process. The local authority costs above are all mutually exclusive as they relate to distinct costs of:

  • the child protection plan
  • residential care and special education associated with FASD
  • housing services associated with moving from homelessness to stable accommodation
  • treatment for alcohol dependency

However, not all benefits under each cost theme are mutually exclusive. For example, in Sarah’s case study, for NHS benefits, it is not clear whether any of the NHS costs for perinatal anxiety and depression are also included in the NHS costs associated with FASD and homelessness. There could be considerable overlap.

To avoid the social cost-benefit being over-estimated by double counting, you can select ‘No’ from the drop-down box when asked to state whether the categories under each cost theme are mutually exclusive. There is an example of this in figure 4, which is a screenshot from the social cost-benefit tool. The results will automatically update and present a range for these categories.

Figure 4. Selecting whether costs are mutually exclusive or not

Step 3: See your results

Once you have entered the number of people each cost theme relates to and you have decided which agency costs are mutually exclusive, you can read the summary of results table. Figure 5 is a screenshot from the social cost-benefit tool which shows the summary of results table for Sarah’s case study. The social benefits presented are those estimated to occur a year following treatment intervention.

Figure 5. Summary table

Remember, the above costs avoided are benefits associated with Sarah and her family specifically. It is unclear whether other people receiving the same intervention would see the same benefits. Also, while this calculation includes the cost of community and residential alcohol treatment it does not include any extra support Sarah may have received, for example from a midwife. You could include additional costs for a more accurate estimate. You could also include lifetime costs, which are available in the database, to make your estimate more accurate.

6. Additional considerations

6.1 Including a cost that is not included in the unit cost database

You can add costs that are not currently in the database if you know the cost value. If you do not know the cost value, you could either try to source the cost value from local partners or contact us via PHE’s parental alcohol and drug use group (login needed) for help.

6.2 Accounting for geographical differences in labour and rent costs

The Excel workbook presents national averages for labour and rent costs. Annex 3 in the Excel workbook includes a market forces factor (MFF) for every upper-tier local authority. The NHS and the Department of Health and Social Care use the MFF to fairly allocate resources. You can use this to adjust national costs to local costs by multiplying the unit cost by the MFF for your local authority.

Alternatively, local partners may hold more accurate information on costs in your local authority.

6.3 The validity of using case studies to estimate social benefit

As with other research methodologies, issues of validity and reliability need to be carefully considered. As mentioned earlier in this guidance, it is important to remember that:

  • estimated costs represent potential benefits specific to the case-study family, not the average benefits we can attribute to the intervention
  • case studies are more robust if the information comes from a variety of corroborative sources
  • you should take care to not double count benefits
  • you should consider attribution where possible (see section 6.4 below)

6.4 Capturing input from other services

Attribution is an assessment of how much of an outcome is due to the contribution of other organisations. For example, specialist treatment for parents alone is rarely enough to address a family’s complex needs. Treatment providers, children and families services and other local support services all work together to help families recover. It will never be possible to get a completely accurate assessment of attribution, but it is important to note that an activity from a specific service may not be the only factor contributing to changes seen in a family.

6.5 Potential benefits might be less than the money invested

You must ensure that you include all the benefits of the interventions used in your case study, where possible.

If you have done this and you still find that costs outweigh benefits, then it is possible that this intervention will not represent value for money for that particular case study. It is important to remember that some interventions do not result in immediate benefits but can provide significant social benefit in years to come.

It is also possible that the result reflects data and evidence constraints. This is a significant limitation of using individual case studies as opposed to using wider and more detailed data on all families receiving interventions.