WHAT IS AN OUTCOME?
❝ an outcome answers the question: 'Is this person better?' ❞
Different stakeholders have very different motivations for wanting to know about outcomes. An outcome can be the result of natural change or of a treatment process.
What does 'being better' mean?
What makes for a good outcome, 'being better', depends on who is asking. People recovering from addiction and their family and friends tend to emphasise abstinence. Other stakeholders are likely to stress their area of interest: for example addiction therapists are interested in a person's quality of life, social workers are interested in child protection, politicians are interested in costs and the public health.
An outcome is the result of an active intervention, such as a treatment programme or joining a self help group, or something more naturally occurring, such as getting older or a new relationship. There may be more than one outcome that is important to measure. For more technical information go to ⏱ Categories of Outcome So, the choice of measure depends on what you want to know:
Exactly what question is the measure being used to answer?
What scales are available and how good are they?
Will the measures answer the questions asked?
How much time will it take to complete the measures and is this reasonable?
How can outcomes be measured?
Some things can be measured directly (biomedical measures) and used as an outcome. Examples in addiction are:
- blood tests of liver function
- urine, hair or saliva tests for drugs - toxicology screening
- blood tests for viruses - hepatitis, HIV
In addiction most outcomes are measured by rating scales which are self completed or rated by a practitioner. Points to watch out for are:
- to what timeframe does the scale apply?
- at what point in the intervention are ratings undertaken?
- how are responses to be interpreted?
What makes a good measurement scale?
All scales need to meet certain quality criteria. A Quality Framework is useful to evaluate scales and typically will include scores for:
- Appropriateness - does the content address what is required?
- Reliability - are the responses to the scale reproducible?
- Validity - does the scale measure what it claims to measure?
- Change - does the scale measure change over time?
- Precision - how accurate is the scale?
- Meaning - can the responses be interpreted into something tangible?
- Acceptability - is the scale understood by and acceptable to respondents?
- Feasibility - is the scale easy to use?
- Availability - is the scale freely available?
For technical information about the Quality Framework used by RESULT go to ⏱ Quality Framework
The World Health Organisation maintains an internationally agreed system of codes and definitions of all mental and physical health disorders. It is called the International Classification of Diseases and is a useful means of communication for research, treatment, and statistical information.
The University of Washington maintains a library of screening and assessment instruments at their Alcohol and Drug Abuse Institute. There are other useful resources on this site including bibliographies (reference lists) on a wide range of topics.
The European Monitoring Center for Drugs and Drug Addiction maintain statistical data on population level outcomes such as mortality and spread of infectious diseases. Statistics are also available on changing patterns of substance use across Europe.
The Cochrane Library Collaboration maintains a reliable and high quality evidence base for the biomedical sciences. The library has useful search capabilities and tutorials on how to use the facility. To see the best outcomes for specific treatment modalities pick out the meta-analyses.
The National Institute for Health and Clinical Excellence is a rich source of evidence in the form of guidelines for practitioners, advice in plain language for the public, a search facility for scientific articles, and tables of data that can be freely accessed by scientists. The statistical analysis behind the guidance is an invaluable resource.