aids package:boot R Documentation _D_e_l_a_y _i_n _A_I_D_S _R_e_p_o_r_t_i_n_g _i_n _E_n_g_l_a_n_d _a_n_d _W_a_l_e_s _D_e_s_c_r_i_p_t_i_o_n: The 'aids' data frame has 570 rows and 6 columns. Although all cases of AIDS in England and Wales must be reported to the Communicable Disease Surveillance Centre, there is often a considerable delay between the time of diagnosis and the time that it is reported. In estimating the prevalence of AIDS, account must be taken of the unknown number of cases which have been diagnosed but not reported. The data set here records the reported cases of AIDS diagnosed from July 1983 and until the end of 1992. The data are cross-classified by the date of diagnosis and the time delay in the reporting of the cases. _U_s_a_g_e: aids _F_o_r_m_a_t: This data frame contains the following columns: '_y_e_a_r' The year of the diagnosis. '_q_u_a_r_t_e_r' The quarter of the year in which diagnosis was made. '_d_e_l_a_y' The time delay (in months) between diagnosis and reporting. 0 means that the case was reported within one month. Longer delays are grouped in 3 month intervals and the value of 'delay' is the midpoint of the interval (therefore a value of '2' indicates that reporting was delayed for between 1 and 3 months). '_d_u_d' An indicator of censoring. These are categories for which full information is not yet available and the number recorded is a lower bound only. '_t_i_m_e' The time interval of the diagnosis. That is the number of quarters from July 1983 until the end of the quarter in which these cases were diagnosed. '_y' The number of AIDS cases reported. _S_o_u_r_c_e: The data were obtained from De Angelis, D. and Gilks, W.R. (1994) Estimating acquired immune deficiency syndrome accounting for reporting delay. _Journal of the Royal Statistical Society, A_, *157*, 31-40. _R_e_f_e_r_e_n_c_e_s: Davison, A.C. and Hinkley, D.V. (1997) _Bootstrap Methods and Their Application_. Cambridge University Press.