Factorial invariance of a questionnaire assessing medication beliefs in Japanese non-adherent groups.
OBJECTIVE
The aim of our study was to verify invariance of latent factors derived from the BMQ (Belief about Medicines Questionnaire) among Japanese adherent and non-adherent groups (adherent to medication and intentionally, unintentionally, and overlapping non-adherent groups) and to estimate mean differences of the latent factors among the groups.


METHODS
A Japanese university hospital.


METHODS
After administration of a cross-sectional survey, covariance structure analyses of the two-factor model were conducted. Groups that exhibited factorial invariance were identified, and structured mean analyses estimated the differences of the latent means of the factors between groups using the bootstrap method without relying on theoretical assumptions for sampling distributions. Effect size was employed as an indicator of these differences.


METHODS
The differences in the latent means of the two factors (the necessity and concerns factors for prescribed medications) across the groups exhibiting factorial invariance, which reflect true differences between them.


RESULTS
Factorial invariance was demonstrated only across adherent and unintentionally non-adherent groups. Unintentionally non-adherent patients had significantly lower latent means for the necessity factor than adherent patients, with a very close to medium effect size (-0.49; 95% CI -0.84, -0.14; bootstrap method).


CONCLUSIONS
A meaningful comparison of BMQ scale scores can be made between adherent and unintentionally non-adherent groups of Japanese patients.
Iihara
Naomi
N
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1, Shido, Sanuki-city, Kagawa 769-2193, Japan. iiharan@kph.bunri-u.ac.jp
Suzuki
Kiyo
K
Kurosaki
Yuji
Y
Morita
Shushi
S
Hori
Keizo
K
D000223:Adaptation, Psychological; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D007722:Health Knowledge, Attitudes, Practice; D006785:Hospitals, University; D006801:Humans; D033182:Intention; D007564:Japan; D008960:Models, Psychological; D010349:Patient Compliance / Q000523:psychology*; D011795:Surveys and Questionnaires; D016312:Treatment Refusal / Q000523:psychology*
Stat Methods Med Res. 1992;1(2):159-81
1341656
J Consult Clin Psychol. 1994 Jun;62(3):429-40
8063970
Psychol Bull. 1990 Mar;107(2):238-46
2320703
Cochrane Database Syst Rev. 2005 Oct 19;(4):CD000011
16235271
Nephrol Dial Transplant. 2004 Dec;19(12):3144-9
15479748
Psychol Bull. 1992 May;111(3):490-504
16250105
Patient Educ Couns. 2008 Feb;70(2):292-9
18068938
J Psychosom Res. 1999 Dec;47(6):555-67
10661603
Res Q Exerc Sport. 1993 Sep;64(3):256-73
8235047
Res Q Exerc Sport. 2004 Sep;75(3):259-71
15487290
JAMA. 2002 Dec 11;288(22):2880-3
12472330
Med Care. 1986 Jan;24(1):67-74
3945130
Eur J Cancer. 2006 Sep;42(14):2271-6
16644208
Ann Pharmacother. 2005 Jul-Aug;39(7-8):1198-203
15956238
Prev Med. 2000 Nov;31(5):584-94
11071840
J Behav Med. 2002 Aug;25(4):355-72
12136497
Int J STD AIDS. 2004 Jan;15(1):38-44
14769170
JAMA. 1993 Jun 2;269(21):2779-81
8492406
Ann Pharmacother. 2006 Oct;40(10):1737-42
16985088
Ethn Dis. 2006 Spring;16(2):551-8
17682262
J Clin Epidemiol. 2006 Jun;59(6):650-1
16713529
Qual Saf Health Care. 2002 Mar;11(1):81-4
12078377
Rheumatology (Oxford). 2005 Jun;44(6):762-7
15741193
Ethn Dis. 2006 Winter;16(1):1-8
16599341
Psychol Health Med. 2003 Nov;8(4):453-63
21974735
J Psychosom Res. 2008 Jan;64(1):41-6
18157998
Med Care. 2004 Mar;42(3):200-9
15076819