The Changing Lives of Older Couples Study (CLOC) is a large multi-wave prospective study of spousal bereavement. The CLOC study is based on a two-stage area probability sample of 1,532 married men and women from the Detroit, Michigan Standardized Metropolitan Statistical Area (SMSA). To be eligible for the study, respondents had to be English-speaking members of a married couple, where the husband was at least age 65. All respondents were non-institutionalized and were capable of participating in a two-hour face-to-face interview.
Baseline face-to-face interviews with the married older adults were conducted between June 1987 and April 1988. Spousal loss was subsequently monitored using monthly death records provided by the State of Michigan and by reading daily obituaries in Detroit-area newspapers. The National Death Index (NDI) and direct ascertainment of death certificates were used to confirm deaths and determine the cause of death. Of the 335 respondents known to have lost a spouse during the five-year study period, 316 were contacted for possible interview (19 persons, or 6% had died during the interim). Of the 316 contacted, 263 persons (83%) participated in at least one of the three follow-up interviews which were conducted at six months (Wave 1), 18 months (Wave 2), and 48 months (Wave 3) after the spouse's death.
Each widowed person was assigned a same-age, same-sex, same-race matched control from the baseline sample. Controls were reinterviewed at each of the three follow-ups (W1, W2, W3). Controls are fewer in number than the widow(er)s at Wave 1 because the initial funding for the control sample was cut and not reinstated until half-way through the data collection period.
The CLOC study, while primarily a prospective study of spousal bereavement, also includes a host of biomedical variables (often referred to as the MacBat variables). The MacBat variables have been merged together with the CLOC data, resulting in a combined dataset with 1532 cases and over 3000 variables covering every aspect of social, psychological, and physical functioning of older adults.
Table 1: Summary of Variables Available at Each Wave
Table 2: Summary of Sample Sizes and Numbers of Variables for Analysis at Each Wave