Several possible solutions might be offered in the pursuit of unbiased truth. The symptom counts may be categorized (for example into affected and unaffected subjects) and models fitted by logistic regression. This approach may minimize spurious interaction in simple cases but usually leads to such a serious loss of power that choosing between models of different complexity will prove difficult if not impossible with feasible sample sizes. It was difficult to find significant results with the large sample sizes used in the simulations.
