Health in California : California health survey.

  • California. Department of Public Health.
Date:
[1957]
Catalogue details

Licence: Public Domain Mark

Credit: Health in California : California health survey. Source: Wellcome Collection.

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    used to derive incidence rates.' These figures show the rate at which new episodes of illness were added to the total of all illnesses existing during the period. . Two measures of effect were used for illnesses. Those which began during the period were di- vided according to whether or not they caused any disability during the period, i.e. into disabling illness and nondisabling illness. In addition, the total number of days of disability during the pe- riod was obtained for all illnesses, whether they began before or during the period. Chronic conditions were defined as all condi- tions existing during the 12 months preceding the week of interview and which were recurrent, lasted three months or longer, or would usually be classed as chronic, e.g. heart disease. They may have begun before or during the period; they may or may not have been currently causing ill- ness. Here diseases were included which would be excluded under “illness’”—diseases under con- trol through medicine or treatment, such as dia- betes, and diseases which are currently quiescent, *For complete definitions, examples and interpretations of the rates used in this monograph, see Appendix C. such as hay fever between seasons. Because of this wide range, looking at chronic conditions pro- vides a broad picture of the amount of disease in a population. More measures of effect of a chronic condition were used than for illnesses as defined in this Survey. Chronic conditions were classified accord- ing to whether they had ever been medically at- tended, and whether in the past 12 months they had been associated with hospitalization, disability, or activity limitation. In order to give a more inclusive measure of the effect of a chronic condi- tion, the classification was carried further: whether the chronic condition had required regu- lar or occasional medical attendance, whether it had caused disability in the past, year and/or whether it had caused limitation of activity. This series of measures of the effect of a chronic condition was used for two principal reasons: to meet as many of the potential uses of morbidity data as possible, and also to explore possible ways of describing disability. While dif- ferent measures of disability are commonly used for different purposes, there are not many meas- ures widely accepted. any disability. of illness during a four-week period. and to diagnostic groups. The word “incidence” has been variously de- fined. However, in this report it means the number of episodes of illness which begin during a specific period of time (four weeks preceding the week of interview). By this definition we include “new” conditions as well as “recurrences” and “relapses.” For some conditions, such as mumps, the initial attack gives immunity to subsequent attacks; for other diseases, such as hay fever, the condition may have acute disabling episodes recurring from time to time although usually it is in a quiescent state. There are still other conditions, such as the common cold, which are acute but which can attack a person repeatedly with complete recovery between each attack. Any of these types will be included in the incidence rate of illness. In examining rates of total illness, certain quali- fications of household morbidity surveys must be borne in mind. The incidence rate probably repre- sents a minimum rate for it depends upon factors such as the number of probing questions used, the time period of inquiry, the training of the in- terviewer and whether or not a person was inter- viewed for himself.2 The rate is also low for conditions which might produce more than one episode of illness during a four-week period, since only the last episode was counted. A General Picture The Survey indicates that on the average each Californian experiences five or six episodes of ill- ness per year, divided about equally between acute and chronic illness. Almost one-half of the epi- sodes of acute illness are due to respiratory dis- eases and one-fourth are due to accidents. * This last methodological point was covered by a Post- Enumeration Survey done in conjunction with the California Health Survey. The results are discussed in Chapter 7 and some indications of what this adjust- ment means to sex-specific rates will be given in this chapter where pertinent to the interpretation.