Skip to main content

Table 3 Alternative estimators for model C

From: Evaluating the administration costs of biologic drugs: development of a cost algorithm

Dependent variable: ADMINCOST or lnADMINCOST

 

GLM (log, Gamma)

PGLM/EEE (QV)

GLM (identity Gaussian)

NLLS

Independent variables

β k ^ (SE)

β k ^ (SE)

β k ^ (SE)

β k ^ (SE)

SUBCUTANEOUS

-2.8255 (0.314)***

-2.6618 (0.369)***

-3.2026 (0.363)***

-3.2026 (0.474)***

INTRAMUSCULAR

-5.0158 (0.393)***

-4.7495 (0.609)***

-5.2737 (0.509)***

-5.2737 (0.664)***

DOSFREQ

0.4015 (0.042)***

0.3754 (0.059)***

0.428 (0.054)***

0.428 (0.07)***

PRODUCTBUND

0.2364 (0.198)

0.2336 (0.19)

0.404 (0.269)

0.404 (0.35)

INDICATN

-0.2352 (0.145)

-0.2592 (0.133)*

-0.2896 (0.183)

-0.2896 (0.283)

DOSFREQ2

-0.00102 (0.0002)***

-0.00093 (0.0001)***

-0.00106 (0.0002)***

-0.00106 (0.0003)***

DOSFREQ.INDICATN

-0.3004 (0.021)***

-0.2775 (0.053)***

-0.3173 (0.028)***

-0.3173 (0.036)***

Intercept

7.3703 (0.257)***

-0.6008 (0.264)

7.1499 (0.349)***

7.1499 (0.455)***

Regression statistics

    

Log pseudo-likelihood (AIC)

-143.3921 (16.377)

—

-16.8641 (2.3182)

—

OD parameter: δ ^ 95 % CI

1.589 (1.251, 1.921)

—

—

—

Link parameter: λ ^ 95 % CI

—

0.078 (-0.2361, 0.3921)

—

—

VF parameter: θ 1 ^ 95 % CI

—

0.0304 (-0.0038, 0.0646)

—

—

VF parameter: θ 2 ^ 95 % CI

—

0.0899 (-0.0038, 0.1836)

—

—

R2 (Adjusted R2)

—

—

0.8923 (0.8285)

0.8923 (0.8692)

  1. Notes: β ^ k = regression coefficients; ***p < 0.01; **p < 0.05; *p < 0.10; SE = heteroskedastic-robust standard error; CI = confidence interval; SUBCUTANEOUS = dummy variable for subcutaneous delivery; GLM = generalized linear modelling; PGLM = Power-GLM; EEE = extended estimating equations; QV = quadratic variance function; NLLS = non-linear least squares; INTRAMUSCULAR = dummy variable for intramuscular delivery; DOSFREQ = dosing frequency; PRODUCTBUND = dummy indicating whether the drug product is sold as a bundled product with some of the equipment and consumables used in drug administration; INDICATN = dummy for type of illness a product is clinically indicated for; AIC = Akaike Information Criterion; OD = over-dispersion; VF = variance function.