Measures that are commonly used in CP

It is hard to know where to start in discussing measures that are commonly used in CP – there are so many measures for so many issues. Rather, it may be important for people to understand some principles about the choice and use of any measure:

  • First, WTQ (‘what’s the question?’). To the extent that measures are tools, we need to be specific about the kind of tool we need, based on the question(s) we are asking.

      • Are we screening to see whether someone does or does not have a condition? This requires measures or tools validated to discriminate.
      • Do we want to describe the details of something? If so, we need measures that capture the relevant features of that condition.
      • Do we want to look for change in function over time? This requires change-detecting ‘evaluative’ measures purpose designed and validated.
      • Do we want to predict some future state or level of functioning? To do this we need measures that have been purpose-designed and validated to fulfill this role.
      • Any measure needs to be used for the purpose(s) intended. We might have an excellent screwdriver, one that can work on a particular kind of screw. It might, however, be quite unusable for another kind of screw.

  • Second, measures need to be used the way the developers recommend. That means :

    • using all the items,
    • using the scales (response options) used by the developers,
    • scoring the measure as the developers did, and
    • being careful to interpret the findings the way the developers intended.

  • Third, if a measure has been developed with and for a particular population (for example, people with CP) it cannot automatically be used with other populations – unless there is further work done to assess whether the measure does indeed work with the new groups. (Think of using an excellent and effective antibiotic for pneumonia, which we diagnosed on the basis of a person’s cough and fever. That treatment will not necessarily work on someone else with cough and fever – for example someone with tuberculosis!)
  • Fourth, we have to be careful not to use measures ‘because we have them and can measure this (phenomenon)’. Remember, WTQ!
  • Finally, people should beware of using ANY measure ‘because everyone else uses it’! Popularity is not a criterion of a measures validity, reliability, and appropriateness to address the WTQ issue!

There are excellent resources that catalogue measures used in, and evaluated for CP. One example is the text by edited by Majnemer (see: