title: Does item overlap render measured relationships between pain and challenging behaviour trivial? Results from a multicentre cross-sectional study in 13 German nursing homes.
abstract: Several studies suggest that pain is a trigger for challenging behaviour in older adults with cognitive impairment. However, such measured relationships might be confounded due to item overlap as instruments share similar or identical items. The purpose of this study was to examine whether the frequently observed association between pain and challenging behaviour might be traced back to item overlap. This multicentre cross-sectional study was conducted in 13 nursing homes and examined pain (measure: Pain Assessment in Advanced Dementia Scale) and challenging behaviour (measure: Cohen-Mansfield Agitation Inventory) in 150 residents with severe cognitive impairment. The extent of item overlap was determined by juxtaposition of both measures' original items. As expected, comparison between these instruments revealed an extensive item overlap. The statistical relationship between the two phenomena can be traced back mainly to the contribution of the overlapping items, which renders the frequently stated relationship between pain and challenging behaviour trivial. The status quo of measuring such associations must be contested: constructs' discrimination and instruments' discrimination have to be discussed critically as item overlap may lead to biased conclusions and assumptions in research as well as to inadequate care measures in nursing practice.
authors.affiliation: Institute of Nursing Science and Practice, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Patrick
authors.initials: P
authors.lastname: Kutschar
authors.affiliation: Institute of Nursing Science and Practice, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Zsuzsa
authors.initials: Z
authors.lastname: Bauer
authors.affiliation: Institute of Nursing Science and Practice, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Irmela
authors.initials: I
authors.lastname: Gnass
authors.affiliation: Institute of Nursing Science and Practice, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Osterbrink
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000523:psychology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000523:psychology / Q000628:therapy; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D009735:Nursing Homes; D015404:Nursing Methodology Research; D059408:Pain Management; D010147:Pain Measurement; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011595:Psychomotor Agitation / Q000523:psychology*
keywords: cognitive impairment; elder care; nursing home care; pain; research methodology