Measurement of morbidity / a report of the Statistics Sub-Committee of the Registrar General's Advisory Committee on Medical Nomenclature and Statistics.

Date:
1954
Catalogue details

Licence: Public Domain Mark

Credit: Measurement of morbidity / a report of the Statistics Sub-Committee of the Registrar General's Advisory Committee on Medical Nomenclature and Statistics. Source: Wellcome Collection.

    9/20 (page 3)
    B. DEFINITIONS I. Definitions of Terms (1) The terms “ sickness ” and “ sick ” (including effects of accident or other violence) have been used in the definitions of rates as general terms and no attempt has been made to define them precisely. Their meaning is likely to vary according to the objects of a particular enquiry and the sources of information available. The words are inserted in italics in the definitions to indicate that more precise terms appropriate to particular enquiries should be substituted for them. Thus, for example, the words “ spell of sickness ” may be replaced by:— spell of sickness absence, or spell of in-patient care and the words “ who are sick ” by:— who are absent sick, who consult their general practitioners, who attend out-patient departments, or who receive in-patient care. (2) The term “ case 99 of sickness is not defined because it is impracticable to give a definition which would be appropriate to all diseases. The general intention is that it should cover the whole course of one disease in one person as far as that course is relevant to the particular enquiry concerned. (3) The term “ disease ” has been used in the report to include sickness arising from accident or other violence. (4) A “ spell99 of sickness is a period during which a person is sick on one day (or shift) or on each of a consecutive series of days (or shifts). Examples are:— a spell of sickness absence, or a spell of in-patient care. (5) The “ duration 99 of a spell of sickness normally includes each of the con¬ secutive series of days for which sickness is recorded. In measuring the duration of a spell of in-patient care, the day on which the patient is discharged should not be counted as well as the day on which he was admitted. (6) The “ number of persons exposed to risk ” at a given time should include all those persons who would, in the event of their becoming sick, be recorded as sick in the context of the particular enquiry; it should exclude any others. (7) The “ total duration of exposure to risk ” is the duration in days (or other time units) of the defined period of observation multiplied by the average num¬ ber of persons exposed to risk per day (or other time unit) during that period. (8) The term “ incidence ” has been avoided in the actual definitions and descriptions of rates, because, although it is often used in the sense of sickness “ beginning ”, it is frequently used also without this restricted connotation. The Sub-Committee therefore decided that current usage of the word is too broad to permit its adoption in the specific sense for which the word “ inception” has been adopted in this Report. II. General Notes (1) Rates as defined may be applied to all causes of sickness, but may equally well be applied to particular causes of sickness and for many purposes will need to be so applied.