Missed nursing care was hypothesized in this study as a mediating variable in the relationship between HPPD and patient falls. To satisfy the requirements for mediation, 3 variables were computed. To establish mediation, the following conditions must be satisfied: (a) HPPD must affect missed nursing care in the first equation; (b) HPPD must affect patient falls in the second equation; and (c) missed nursing care must affect patient falls in the third equation. Then, if these conditions are met, the effect of HPPD on patient falls must be less in the third equation than in the second equation, thus establishing mediation.
In equation 1, missed nursing care, the mediator variable, was regressed on the predictor variable, HPPD. As noted in the Figure, results indicated that HPPD was significantly associated with missed nursing care (F1,120 = 8.46, P = .004). Hour per patient day explained 6.7% of the variance in missed nursing care.