Pain over speed bumps in diagnosis of acute appendicitis

22 Jan

that this study (from the BMJ) exists in literature is awesome, in my opinion:

Ashdown HF, et al:

101 patients aged 17-76 years referred to  surgery for possible appendicitis.

64 participants who had traveled over speed bumps on their journey to hospital.

54/64 (total participants) were “speed bump positive.”



34/64 had a confirmed histological diagnosis of appendicitis

33/34 (with appy diagnosis) reported increased pain over speed bumps.


  • sensitivity was 97% (95% confidence interval 85% to 100%),
  • specificity was 30% (15% to 49%)
  • positive predictive value was 61% (47% to 74%),
  • negative predictive value was 90% (56% to 100%).
  • likelihood ratios were 1.4 (1.1 to 1.8) for a positive test result and 0.1 (0.0 to 0.7) for a negative result. 
  • Speed bumps had a better sensitivity and negative likelihood ratio than did other clinical features assessed, including migration of pain and rebound tenderness.


Presence of pain while travelling over speed bumps was associated with an increased likelihood of acute appendicitis.

As a diagnostic variable, it compared favourably with other features commonly used in clinical assessment

OLD POST ON positive likelihood ratios FOR SIGNS/SYMPTOMS OF APPENDICITIS, for those interested.


“speed bump sign”

  • good sensitivity
  • bad specificity
  • about as good as our other clinical signs on its own (which is not terribly good)
  • as an isolated finding, take it with a grain of salt, but worth adding to your collection of clinical findings

my two cents: 

  • I sometimes jostle or kick the bed/stretcher of my abdominal pain patients as a sideways eval of peritoneal irritation or abdominal discomfort, so its nice to know there might be some small evidence it could be somewhat useful.

References: bmj article; picture


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