Appendix IX

Standardization of Outcomes Tables

Although it is not possible to completely standardize outcomes tables because of the diversity of issues among services, the following proposal gives some preferred entries for authors to use in outcomes tables where possible:

1. Time frame:
   For services with extended time frame:

   10 years (5 years has typically been used, though 5 years is a short time for many consequences of screening and prophylactic interventions. Since all these calculations require some assumptions, extrapolating to 10 years seems reasonable.). Alternatives: 5 years, lifetime.

   For services with short time frame (pregnancy, for example)
   1 year.

2. Population:

   Express this number as per 1000 individuals targeted, e.g., per 1000 women age 40-49
     Rationale: Services with large magnitude of impact should have substantial numbers of outcomes when expressed per 1000 individuals, those with less than 1 outcome averted will clearly be interpreted as having relatively small impact.

3. Interventions:

   Interventions should be shown in columns and described. For repeated services, e.g., annual fecal occult blood test (FOBT), number of services should be identified.

4. Parameter estimates:

   Important parameters should be provided, such as appropriate:
      Screening results: sensitivity, specificity
      Prevalence of condition
      Adherence (to screening, treatment)
      Effectiveness
      Costs where appropriate (screening, treatment, costs averted)
   Intermediate outcomes
      Number identified (with and without the condition)
      Number treated

5. Outcome Measures (harms and benefits)

   Deaths where relevant
   Important health outcome, e.g. strokes averted or cancers caused
   QALY’s if possible
   Harms: adverse events/states

6. Number needed to screen/treat/counsel

   Express in outcome terms (NNS to avert one death)
   NNC to achieve change in behavior should only be shown if NNC for a health outcome also shown.

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