Key points are not available for this paper at this time.
Sander Greenland, Ruth M. Mickey, Closed Form and Dually Consistent Methods for Inference on Strict Collapsibility in 2 × 2 × K and 2 × J × K Tables, Journal of the Royal Statistical Society. Series C (Applied Statistics), Vol. 37, No. 3 (1988), pp. 335-343
Greenland et al. (Fri,) studied this question.