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Centre for Evidence-
Based Medicine

Completed Diagnosis Worksheet for Evidence-Based Mental Health


Mintz et al Questionnaire for eating disorder: reliability and validity of operationalising DSM-IV criteria into a self-report format Journal of Counseling Psychology 44 63-79.

Are the results of this diagnostic study valid?

  1. Was there an independent, blind comparison with a reference ("gold") standard of diagnosis?
    Yes - DSM-IV criteria for eating disorder made by structured clinical interview
  2. Was the diagnostic test evaluated in an appropriate spectrum of patients (like those in whom it would be used in practice)?
  3. Was the reference standard applied regardless of the diagnostic test result?

Are the valid results of this diagnostic study important?

Questionnaire for Eating Disorder Diagnoses (Q-EDD) Eating disorder No eating disorder Likelihood Ratio
Positive 32 2 50
Negative 1 101 0.03
Totals 33 103
  • For pre-test probabilities in the 20-50% range, a positive test yields post-test probabilities of 94-98% (in the latter case, a SpPin1).
  • For pre-test probabilities in the 20-50% range, a negative test yields post-test probabilities of <1% (in the latter case, a SnNout2).
  • So it can give quite useful results.
  1. When a diagnostic test has a very high Specificity, a Positive result Rules-In the diagnosis.
  2. When a diagnostic test has a very high Sensitivity, a Negative result Rules-Out the diagnosis.

Can you apply this valid, important evidence about a screening test in helping students with eating disorders?

Do these results apply to your patient?

  1. Is the diagnostic test available, affordable, accurate, and precise in your setting?
    Needs to be assessed in each setting.
  2. Can you generate a clinically sensible estimate of your patient's pre-test probability (from practice data, from personal experience, from the report itself, or from clinical speculation)
    Approximately 30%.
  3. Will the resulting post-test probabilities affect your management and help your patient? (Could it move you across a test-treatment threshold?; Would your patient be a willing partner in carrying it out?)
    If a student screens as positive, it would be worth offering a follow-up appointment.
  4. Would the consequences of the test help your patient?
    Probably. There are highly effective treatments (cognitive therapy, interpersonal psychotherapy) available for the most common eating disorders such as bulimia.

Additional Notes


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