Further studies with data based on a long followup will be necessary to evaluate reliable tumor incidences for these low suspicion groups.
Only one patient in the non-suspicion group suffered from paroxysmal cough.
There were 17 true-negative PCR and microarray assay results in the PJI-suspicion group.
All four patients with exclusively URTI fell into the clinical non-suspicion group.
Clinical suspicion is a strong prognostic factor for this outcome: in the no-ultrasound arm, 97% of the strong-suspicion group but only 32% of the moderate-suspicion group received hip treatment.
In the second season another seven cases were found in the non-suspicion group (7/257 = 2,7%) (group E).
In the UK Hip trial, ultrasound reduced the risk of any hip treatment from 97%to68%8% in the strong-suspicion group.
A common risk ratio for avoiding hip treatment is not possible, since the risk ratio is over 9 in the strong-suspicion group, and multiplying the 68% risk of avoiding hip treatment in the strong-suspicion group by 9 would result in a risk over 100%.
Under the null hypothesis of a common risk ratio for hip treatment, the 32% risk in the moderate-suspicion group would be reduced to 23%, but the null hypothesis of a common risk difference implies a reduction to 4.1%, and the null hypothesis of a common odds ratio implies a reduction to 3.5%.
