Calculation of reference intervals for complete blood count in elderly
population using patient data
Conventional method of calculation of reference interval (RI) for
complete blood count (CBC) parameters for elderly population is
challenging as finding healthy elderly volunteers is difficult. This
study was carried out to assess the possibility of use of stored patient
data of CBC reports of elderly patients in calculation of RI for CBC
parameters. A retrospective, cross sectional study was carried out in a
hospital laboratory using stored data of patients >65 years
of age (n=3094). Relevant clinical criteria and statistical tools were
used to refine data to obtain representative samples for each CBC
parameter. RI were calculated using standard statistical tools.
Calculated RI were compared with RI provided by the manufacturer (RI for
>18years old) and with RI defined in five other countries.
All data sets showed normal distribution thus, parametric approach was
adopted to calculate RI. The RI of all CBC parameters were similar to
those of other countries. The RI obtained in this study for red cell
indices, platelet count and white blood cells are similar to the RI
provided by the manufacturer for adults. The RI obtained for RBC, Hb,
PCV were clinically significantly lower compared to the RI provided by
the manufacturer for adults. When appropriate selection criteria and
relevant statistical tools are applied, patient data can be effectively
used to calculate RI for CBC parameters in elderly.