fev                   package:msm                   R Documentation

_F_E_V_1 _m_e_a_s_u_r_e_m_e_n_t_s _f_r_o_m _l_u_n_g _t_r_a_n_s_p_l_a_n_t _r_e_c_i_p_i_e_n_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     A series of measurements of the forced expiratory volume in one
     second (FEV1) from lung transplant recipients, from six months
     onwards after their transplant.

_U_s_a_g_e:

     data(fev)

_F_o_r_m_a_t:

     A data frame containing 5896 rows.  There are 204 patients, the
     rows are grouped by patient number and ordered by days after
     transplant. Each row represents an examination and containing an
     additional covariate.

       'ptnum'  (numeric)  Patient identification number.
        'days'  (numeric)  Examination time (days after transplant).
         'fev'  (numeric)  Percentage of baseline FEV1. A code of 999 indicates the patient's date of death.
       'acute'  (numeric)  0/1 indicator for whether the patient suffered an acute infection or rejection
                           within 14 days of the visit.

_D_e_t_a_i_l_s:

     A baseline "normal" FEV1 for each individual is calculated using
     measurements from the first six months after transplant. After six
     months, as presented in this dataset, FEV1 is expressed as a
     percentage of the baseline value.

     FEV1 is monitored to diagnose bronchiolitis obliterans syndrome
     (BOS), a long-term lung function decline, thought to be a form of
     chronic rejection.  Acute rejections and infections also affect
     the lung function in the short term.

_S_o_u_r_c_e:

     Papworth Hospital, U.K.

_R_e_f_e_r_e_n_c_e_s:

     Jackson, C.H. and Sharples, L.D. Hidden Markov models for the
     onset and progression of bronchiolitis obliterans syndrome in lung
     transplant recipients _Statistics in Medicine_, 21(1): 113-128
     (2002).

