Validation of the Patient Activation Measure (PAM-13) among adults with cardiac conditions in Singapore
The Patient Activation Measure (PAM-13) measures patients’ knowledge, skill, and confidence in chronic condition self-management. The purpose of this study was to assess the validity of PAM-13 (English version) among English-speaking adults with cardiac conditions in Singapore.
A cross-sectional study was conducted in a convenient sample of 270 heart clinic patients. Using the unitary concept of validity, evidence of (1) internal structure via data quality, unidimensionality, differential item functioning, and internal consistency, (2) response process through item difficulty and item fit using Rasch modeling, and (3) relationship to other variables via correlations with depression and self-efficacy were examined.
The item response was high with only one missing answer. All items had a small floor effect, but nine out of 13 items had a ceiling effect larger than 15 %. Cronbach’s α was 0.86, and average inter-item correlations was 0.324. Results suggested unidimensionality; however, differences in item difficulty ranking were found. A low, negative correlation was found with depression, while a moderate, positive correlation was found with self-efficacy.
Evidence in all three areas of validity were mixed. Caution should be exercised when using categorical activation “level” to inform clinical decisions.
KeywordsPatient Activation Measure Cardiac Singapore Chronic disease Self-management Validation
This study was funded by a research grant awarded by the Singapore Association of Occupational Therapists (Grant Number SAOT/RG01/2015).
Compliance with ethical standards
Conflict of interest
Bi Xia Ngooi received the above-mentioned research grant from the Singapore Association of Occupational Therapists. Tanya Packer, Grace Warner, George Kephart, Karen Koh, Raymond Wong, and Serene Lim declared that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the Singapore’s National Healthcare Group Domain Specific Review Board and Canada’s Dalhousie University Health Sciences Research Ethics Board, and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
- 1.Acock, A. C. (2008). A gentle introduction to STATA (2nd ed.). Texas: Stata Press.Google Scholar
- 4.American Educational Research Association (AERA), American Psychological Association (APA), National Council on Measurement in Education (NCME). (1999). Standards for education and psychological testing. Washington, DC: American Educational Research Association.Google Scholar
- 7.Brenk-Franz, K., Hibbard, J. H., Herrmann, W. J., Freund, T., Szecsenyi, J., Djalali, S., et al. (2013). Validation of the German version of the Patient Activation Measure 13 (PAM13-D) in an international multicentre study of primary care patients. PLoS ONE, 8, e74786. doi: 10.1371/journal.pone.0074786.CrossRefPubMedPubMedCentralGoogle Scholar
- 8.Bond, T. G., & Fox, C. M. (2007). Applying the Rasch model. Fundamental measurement in the human sciences (2nd ed.). Mahwah, NJ: Lawrence Erlbaum Associates.Google Scholar
- 9.Chen, W.-H., Lenderking, W., Jin, Y., Wyrwich, K. W., Gelhorn, H., & Revicki, D. A. (2014). Is Rasch model analysis applicable in small sample size pilot studies for assessing item characteristics? An example using PROMIS pain behavior item bank data. Quality of Life Research, 23, 485–493.CrossRefPubMedGoogle Scholar
- 10.Chong, S. A., Abdin, E., Vaingankar, J. A., Heng, D., Sherbourne, C., Yap, M., et al. (2012). A population-based survey of mental disorders in Singapore. ANNALS Academy of Medicine Singapore, 41, 49–66.Google Scholar
- 12.Fowles, J. B., Terry, P., Si, M., Hibbard, J., Bloom, C. T., & Harvey, L. (2009). Measuring self-management of patients’ and employees’ health: Further validation of the Patient Activation Measure (PAM) based on its relation to employee characteristics. Patient Education & Counselling, 77, 116–122.CrossRefGoogle Scholar
- 18.Hibbard, J. H., & Gilburt, H. (2014). Supporting people to manage their health: An introduction to patient activation. United Kingdom: The King’s Fund. Retrieved from http://www.kingsfund.org.uk/publications/supporting-people-manage-their-health.
- 19.Hinkle, D. E., Wiersma, W., & Jurs, S. G. (1998). Applied statistics for the behavioural sciences (4th ed.). Boston, MA: Houghton Mifflin Company.Google Scholar
- 21.Insignia Health, L. L. C. (2011). Patient Activation Measure (PAM) 13 TM: license materials. Portland: Insignia Health.Google Scholar
- 28.Mair, P., & Hatzinger, R. (2006). eRm; extended Rasch models. R package version 0.3.2. http://CRAN.R-project.org/. Accessed October, 2013.
- 29.Mair, P., & Hatzinger, R. (2007). CML based estimation of extended Rasch models with the eRm package in R. Psychology Science, 49, 26–43.Google Scholar
- 33.Moljord, I. E. O., Lara-Cabrera, M. L., Perestelo-Perez, L., Rivero-Santana, A., Eriksen, L., & Linaker, O. M. (2015). Psychometric properties of the Patient Activation Measure-13 among out-patients waiting for mental health treatment: A validation study in Norway. Patient Education and Counselling, 98, 1410–1417. doi: 10.1016/j.pec.2015.06.009.CrossRefGoogle Scholar
- 34.Ministry of Health, Singapore. (2011). National Health Survey. Retrieved from https://www.moh.gov.sg/content/dam/moh_web/Publications/Reports/2011/NHS2010%20-%20low%20res.pdf.
- 35.Ministry of Health, Singapore. (2014). Top 10 conditions of hospitalisation. Retrieved from https://www.moh.gov.sg/content/moh_web/home/statistics/Health_Facts_Singapore/Top_10_Conditions_of_Hospitalisation.html.
- 36.Ministry of Health, Singapore. (2014). Principal causes of death. Retrieved from https://www.moh.gov.sg/content/moh_web/home/statistics/Health_Facts_Singapore/Principal_Causes_of_Death.html.
- 37.Ministry of Health, Singapore. (2014). Disease burden. Retrieved from https://www.moh.gov.sg/content/moh_web/home/statistics/Health_Facts_Singapore/Disease_Burden.html.
- 38.Ngooi, B. X. (2016). Validation of the Patient Activation Measure (PAM-13) among adults with cardiac conditions in Singapore: A mixed methods study. Unpublished master’s thesis, Dalhousie University, Halifax, Canada.Google Scholar
- 40.R Development Core Team. (2006). R: A language and environment for statistical computing. Vienna: R Development Core Team.Google Scholar
- 42.Rasch, G. (1960). Probabilistic models for some intelligence and attainment tests. Copenhagen: Danish Institute for Educational Research.Google Scholar
- 46.Singapore Department of Statistics. (2010). Census of population 2010 statistical release 1: Demographics characteristics, education, language and religion. Retrieved from http://www.singstat.gov.sg/publications/publications_and_papers/cop2010/census10_stat_release1.html.
- 47.Singapore Department of Statistics. (2012). Key household income trends. Retrieved from http://www.singstat.gov.sg/publications/publications_and_papers/household_income_and_expenditure/pp-s19.pdf.
- 53.Stanford Patient Education Research Center. (2012). Self-efficacy for managing chronic disease 6-item scale. Retrieved from http://patienteducation.stanford.edu/research/secd6.html.
- 54.StataCorp. (2015). Stata 14 [computer software]. USA: StataCorp LP.Google Scholar
- 56.Sung, S. C., Low, C. C., Fung, D. S., & Chan, Y. H. (2013). Screening for major and minor depression in a multiethnic sample of Asian primary care patients: A comparison of the nine-item Patient health questionnaire (PHQ-9) and the 16-item quick inventory of depressive symptomatology—self-report (QIDS-SR16). Asia-Pacific Psychiatry, 5, 249–258.CrossRefPubMedGoogle Scholar
- 58.World Health Organisation. (2013). Adherence to long-term therapies: Evidence for action. Retrieved from www.who.int/chp/knowledge/publications/adherence_full_report.pdf.
- 59.World Health Organisation. (2013). Health systems strengthening glossary. Retrieved from http://www.who.int/healthsystems/hss_glossary/en/index8.html.