The necessity-concerns framework: a multidimensional theory benefits from multidimensional analysis.
BACKGROUND
Patients' medication-related concerns and necessity-beliefs predict adherence. Evaluation of the potentially complex interplay of these two dimensions has been limited because of methods that reduce them to a single dimension (difference scores).


OBJECTIVE
We use polynomial regression to assess the multidimensional effect of stroke-event survivors' medication-related concerns and necessity beliefs on their adherence to stroke-prevention medication.


METHODS
Survivors (n = 600) rated their concerns, necessity beliefs, and adherence to medication. Confirmatory and exploratory polynomial regression determined the best-fitting multidimensional model.


RESULTS
As posited by the necessity-concerns framework (NCF), the greatest and lowest adherence was reported by those necessity weak concerns and strong concerns/weak Necessity-Beliefs, respectively. However, as could not be assessed using a difference-score model, patients with ambivalent beliefs were less adherent than those exhibiting indifference.


CONCLUSIONS
Polynomial regression allows for assessment of the multidimensional nature of the NCF. Clinicians/Researchers should be aware that concerns and necessity dimensions are not polar opposites.
The George Washington University, Washington, DC, 20052, USA, lalisonphillips@gmail.com.
L Alison
LA
Phillips
Michael A
MA
Diefenbach
Ian M
IM
Kronish
Rennie M
RM
Negron
Carol R
CR
Horowitz
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D055118:Medication Adherence / Q000523:psychology*; D008875:Middle Aged; D008960:Models, Psychological; D012044:Regression Analysis; D020521:Stroke / Q000188:drug therapy* / Q000523:psychology*; D017741:Survivors / Q000523:psychology; D016903:Drug Monitoring