pbcseq               package:survival               R Documentation

_M_a_y_o _C_l_i_n_i_c _P_r_i_m_a_r_y _B_i_l_i_a_r_y _C_i_r_r_h_o_s_i_s, _s_e_q_u_e_n_t_i_a_l _d_a_t_a

_D_e_s_c_r_i_p_t_i_o_n:

     This data is a continuation of the PBC data set, and contains the
     follow-up laboratory data for each study patient. An analysis
     based on the data can be found in Murtagh, et. al.

     The primary PBC data set contains only baseline measurements  of
     the laboratory  paramters.  This data set contains multiple
     laboratory results, but only on the 312 randomized patients.  Some
     baseline data values in this file differ from the original PBC
     file, for instance, the data errors in prothrombin time and age
     which were discovered after the orignal analysis (see Fleming and
     Harrington, figure 4.6.7).

     One "feature" of the data deserves special comment.  The last
     observation before death or liver transplant often has many more
     missing covariates than other data rows.  The original clinical
     protocol for these patients specified visits at 6 months, 1 year,
     and annually thereafter.  At these protocol visits lab values were
     obtained for a large pre-specified battery of tests.  "Extra"
     visits, often undertaken because of worsening medical condition,
     did not necessarily have all this lab work.  The missing values
     are thus potentially informative.

_U_s_a_g_e:

     pbc

_F_o_r_m_a_t:


       id:        case number
       age:       in years
       sex:       m/f
       trt:       1/2/NA for D-penicillmain, placebo, not randomised
       time:      number of days between registration and the earlier of death,
                  transplantion, or study analysis in July, 1986
       status:    status at endpoint, 0/1/2 for censored, transplant, dead
       day:       number of days between enrollment and this visit date
                  all measurements below refer to this date
       albumin:   serum albumin (mg/dl)
       alk.phos:  alkaline phosphotase (U/liter)
       ascites:   presence of ascites
       ast:       aspartate aminotransferase, once called SGOT (U/ml)
       bili:      serum bilirunbin (mg/dl)
       chol:      serum cholesterol (mg/dl)
       copper:    urine copper (ug/day)
       edema:     0 no edema, 0.5 untreated or successfully treated
                  1 edema despite diuretic therapy
       hepato:    presence of hepatomegaly or enlarged liver
       platelet:  platelet count
       protime:   standardised blood clotting time
       spiders:   blood vessel malformations in the skin
       stage:     histologic stage of disease (needs biopsy)
       trig:      triglycerides (mg/dl)

_S_o_u_r_c_e:

     T Therneau and P Grambsch, "Modeling Survival Data: Extending the
     Cox Model", Springer-Verlag, New York, 2000. ISBN: 0-387-98784-3.

_R_e_f_e_r_e_n_c_e_s:

     Murtaugh PA. Dickson ER. Van Dam GM. Malinchoc M. Grambsch PM.
     Langworthy AL. Gips CH.  "Primary biliary cirrhosis: prediction of
     short-term survival based on repeated patient visits." Hepatology.
     20(1.1):126-34, 1994.

     Fleming T and Harrington D., "Counting Processes and Survival
     Analysis", Wiley, New York, 1991.

