Quantitative study of recall of life events

Abstract

QUESTIONNAIRE and interview protocols designed to elicit information about an individual’s personal and social history (as in the medical or psychiatric interview) are usually assumed to derive valid information from the subject. Recent studies [l, 21 questioning this assumption, have been fraught with difficulties including the bias of report by proxy and the lack of adequate standardization of question administration; but most importantly, these studies were devoid of an approach to the validity of recall. The concept that validity of recall is related to the saliency of illness has been well established in health interview studies [3-51. This investigation establishes that consistency of recall is similarly related to the saliency of life events and infers that if an event is recalled consistently, it is salient to the individual and may indirectly reflect validity of recall. METHODS AND MATERIALS The present Schedule of Recent Experience (SRE) questionnaire is self-administered and contains three parts. The face sheet documents personal information pertaining to residence, occupational, social, and marital status, etc. A separate attached sheet asks for information concerning the health of the individual over a IO-year period. The body of the instrument consists of forty items (Table 1) to which the subjects are asked to respond. The forty items refer to life events, either indicative of the life style of the individual or indicative of occurrences involving the individual. In previous studies [6-81 a method was defined for assigning a magnitude of significance to these events. The values are defined as life change units or LCU. It is clear that some items have more significance or salience than others, ranging from 11 to 100 LCU. Twelve of the forty items in the SRE ask the subject to place a mark for the year the item occurred, while 28 of the items ask the subject to respond with a number, i.e. they ask the subject to list “the number of times” that an item occurred for each year (example in Table 2). If the response to an item is positive, the subject places a mark or number under the year or years in which the event occurred. If the item does not apply, the subject marks the “does not apply” space. In the summer of 1964, eighty-eight resident physicians in the University of Washington integrated residency program completed and returned the questionnaire. In the spring of 1965, the same instrument was again completed by fifty-four of the eighty-eight subjects. Thus, fifty-four paired sets of records were obtained, with the time interval of approximately 9 months between the initial response or Time 1 (Tl) and the second response or Time 2 (T2). The questionnaire was scored in the following manner. The number of marks or numbers for each item were tabulated, multiplied by the value of the item (item LCU), and then summed to obtain the subject’s total life change units (total LCU) for each year. Figure 1 shows the total LCU scores of one individual obtained over the lo-year period for the two administrations of the questionnaire. Similar data for the fifty-four subjects showed that the results obtained from the first administration of the questionnaire (Tl) often differed from those of the second administration of the questionnaire (T2). For the purpose of this study, if the score difference between the total Time 1 and Time 2 LCU for the year was forty LCU or greater, that score difference was labeled ‘discrepant.’ A score difference less than forty LCU was labeled ‘non-discrepant.’ The criterion point of forty LCU score difference as discrepant was based on the fact that the standard deviation of the mean score difference between