The americans' changing lives (acl) study followed a nationally representative sample of americans ages 25 and older for 15 years beginning in 1986 and ending in 2001, assessing their physical health at four times during the 15-year period (house et al., 2005). the main finding of the study was that

Awaiver of the requirement for documentation of informed consent may be granted when: the investigator has no convenient place to store signed consent forms separate from the research datathe only record linking the subject and the research is the consent document and the principal risk is a breach of confidentiality.potential subjects might find some of the research questions embarrassing, personal, or intrusivethe subjects are literate in their own language; however, they do not read, write, or speak english