Functions & Formulae

Maps the actual costs, case numbers and expected costs at national mean unit costs of two providers to the ratio of their crude costs per case, the ratio of their expected costs per case, the ratio of their indirectly standardised cost indices and a flag for a crude ranking that the adjustment reverses. The article's three methods are live and are cited, not restated. Cost per weighted case, C_h divided by the sum of the case weights, is C_h / CM_h with CM_h = sum n_hg w_g of HE-FM-CWT-003, equal to c_bar times R_h, and the case mix index CMI_h = CM_h / n_h is an output of HE-CF-CWT-001, so the article's (C_h / n_h) / CMI_h is the same quantity. With the weights w_g = c_bar_g / c_bar of HE-FM-CWT-001 the expected cost E_h = sum n_hg c_bar_g equals CM_h times c_bar, so the cost index I_h = 100 A_h / E_h is 100 times R_h of HE-FM-CWT-003, and HE-FM-ALOS-004 applies the same indirect standardisation to bed-days. The PROMs adjusted score Adj_j is the mean over a provider's patients of the need-standardised value of HE-FM-HEQ-002, y_i minus yX_i plus y_bar, with the case-mix prediction in place of yX_i. Direct standardisation on a common mix is the weighted sum of HE-FM-INEQ-001, with case groups in place of age groups, unit costs in place of rates and the pooled case shares as the standard. HE-ER-CWT-004 and HE-ER-ALOS-006 show in numbers a crude ranking that adjustment reverses, and this package adds the condition under which the reversal happens. HE-AS-CWT-006 states that up-coding raises CM_h and lowers R_h with no change in efficiency. The article's upcoding step is HE-FM-CWT-003 recomputed on the recoded counts, an expected cost of E_h plus the number of cases moved times the gap between the two groups' national mean unit costs, so it is cited, not restated. The case mix index and the observed-to-expected benchmark comparison have their own pages. Notation follows the Case-Mix Adjustment article.