Estimated regressions of average total and average on-site cost per patient-year of antiretroviral therapy in 45 facilities in Zambia.

Note:**p*paCoefficients in columns (5) and (6) are estimated by Zellner’s seemingly unrelated regression method using Stata’s sureg command.bPredicted values in columns (7) and (8) are calculated from the coefficients in columns (5) and (6) respectively, as explained in the text.cValues of p for “Early Start” are the significance level at which the joint hypothesis can be rejected that neither baseline CD4 nor proportion of patients initiating at WHO stage IV influences the dependent variable. For the two equations estimated jointly (columns (5) and (6)) the p-value is the probability that these four estimated coefficients could occur if all four parameters were actually zero.