Assessing the Role of Selection Bias in the Protective Relationship Between Caregiving and Mortality: the Caregiver-Study of Osteoporotic Fractures.

We examined possible selection bias due to 1) sampling decisions and 2) selective participation among women (baseline mean age=79 years) in Caregiver-SOF (1999-2009), an ancillary study to the Study of Osteoporotic Fractures (SOF). Caregiver-SOF includes 1,069 SOF participants (35% caregivers) from Baltimore, Maryland; Minneapolis, Minnesota; Monongahela Valley, Pennsylvania; and Portland, Oregon. Participants were identified by screening all SOF participants for caregiver status (1997-99; n=4,036; 23% caregivers) and rescreening a subset of caregivers and non-caregivers matched on sociodemographic factors 1-2 years later. Adjusted hazards ratios (aHR) related caregiving to 10-year mortality in all women initially screened, subsamples representing key points in constructing Caregiver-SOF, and Caregiver-SOF. Caregivers had better functioning than non-caregivers at each screening. The association between caregiving and mortality in women invited to participate in Caregiver-SOF (41% died; aHR=0.74, 95% confidence interval [CI]: 0.61, 0.89) was slightly more protective than that in all initially screened women (37% died; aHR=0.83, 95% CI: 0.73, 0.95), indicating little evidence of selection bias due to sampling decisions; and similar to that in Caregiver-SOF (39% died; aHR=0.71, 95% CI: 0.57, 0.89), indicating no participation bias. These results add to a body of evidence that informal caregiving may impart health benefits.
PMID: 31429867 [PubMed - as supplied by publis...

Source: Am J Epidemiol - August 19, 2019 Category: Epidemiology Authors: Smith ML, Heeren TC, Ranker LR, Fredman L Tags: Am J Epidemiol Source Type: research