Evidence is insufficient because of: 1  The limited number or size of studies. 2  Important flaws in study design or methods. 3  Inconsistency of findings across individual studies. 4  Gaps in the chain of evidence. 5  Findings not generalizable to routine primary care practice. 6  Lack of information on important health outcomes.
Definition of jerk for English Language Learners. : 1  a stupid person or a person who is not well-liked or who treats other people badly. : 2  a quick pull or twist. : 3  a sudden sharp movement.
jerk-an abrupt spasmodic movement. jerking, jolt, saccade. movement, motility, motion, move-a change of position that does not entail a change of location; the reflex motion of his eyebrows revealed his surprise; movement is a sign of life; an impatient move of his hand; gastrointestinal motility.