LactationThe period of time during which a woman is providing her breast milk to an infant or child.Legally Authorized Representative (LAR)A person authorized either by statute or by court appointment to make decisions on behalf of another person. In human subjects research, an individual or judicial or other body authorized under applicable law to consent on behalf of a prospective subject to the subject's participation in the procedure(s) involved in the research [Federal Policy §___.102(c)].Limited Data Sets (LDS)Concerning the type of data collected, Limited Data Sets contain "PHI that excludes 16 categories of direct identifiers and may be used or disclosed, for purposes of research, public health, or health care operations, without obtaining either an individual's Authorization or a waiver or an alteration of Authorization for its use and disclosure, with a data use agreement." A limited data set may include city; state; ZIP code; elements of date; and other numbers, characteristics, or codes not listed as direct identifiers. Direct identifiers listed in the Privacy Rule's limited data set provisions apply both to information about the individual and to information about the individual's relatives, employers, or household members. (See also: Direct Identifiers Not Allowed in Limited Data Sets and Data Use Agreement.)Lod ScoreAn expression of the probability that a gene and a marker are linked.Longitudinal StudyA study designed to follow participants forward through time.