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European Journal of Clinical Pharmacology

, Volume 72, Issue 11, pp 1381–1389 | Cite as

Adherence to antidepressants among women and men described with trajectory models: a Swedish longitudinal study

  • Ann-Charlotte Mårdby
  • Linus Schiöler
  • Karolina Andersson Sundell
  • Pernilla Bjerkeli
  • Eva Lesén
  • Anna K. Jönsson
Pharmacoepidemiology and Prescription

Abstract

Purpose

The purpose of this study are to analyse adherence to antidepressant treatment over 2 years in Sweden among women and men who initiated treatment with citalopram and to identify groups at risk of non-adherence using trajectory models.

Methods

The study population, including individuals 18–85 years who initiated citalopram use between 1 July 2006 and 30 June 2007, was identified in the Swedish Prescribed Drug Register and followed for 2 years. Adherence was estimated with continuous measure of medication acquisition (CMA) and group-based trajectory modelling, a method which describes adherence patterns over time by estimating trajectories of adherence and the individual’s probability of belonging to a specific trajectory.

Results

The study population included 54,248 individuals, 64 % women. Mean CMA was 52 % among women and 50 % among men (p < 0.001). Five different adherence patterns (Trajectories) were identified. Similar proportion of women and men belonged to each Trajectory. Around 29 % of the women and 27 % of the men belonged to the Trajectory which showed full adherence throughout the 2-year study period. The other four Trajectories showed adherence that declined to different degrees and at different stages in time. Having low socioeconomic status was more common among individuals in Trajectories showing declining adherence than in the adherent Trajectory.

Conclusions

Using trajectory modelling, five Trajectories describing different patterns of adherence to citalopram treatment over time were identified. A large proportion discontinued treatment early and having low socioeconomic status increased the risk of being non-adherent.

Keywords

Medication adherence Swedish prescribed drug register Gender Antidepressants Trajectory models 

Notes

Acknowledgments

The data collection for this work has been supported by the National Corporation of Swedish Pharmacies (Apoteket AB). The Swedish Medical Products Agency provided funding for this project for author AKJ, PJ, and for statistical assistance. The county council of Östergötland provided funding for this project for author AKJ.

Contribution of authors

A-CM, AKJ, KAS, PB, and EL conceived the study question. A-CM organised the study, interpreted the results, and drafted the manuscript. AKJ processed the data, conducted statistical analyses, interpreted the results, and drafted the manuscript. LS processed the data and conducted statistical analyses. PB validated the algorithm. LS, KAS, PB, and EL contributed to the interpretation of the results and critically revised the manuscript for important intellectual content. All authors have read and approved of the final manuscript.

Compliance with ethical Standards

The study was performed in compliance with the Declaration of Helsinki from 1964 and its later amendments. The Regional Ethics Review Board in Gothenburg, Sweden, has approved the RARE-project before start, No. 284–09. With the ethics approval, the register data was retrieved from and linked together by the Statistics Sweden and Swedish National Board of Health and Welfare. The data was delivered in de-identified files with a random serial number instead of the personal identity numbers. In concordance with the ethics approval, no formal consent was obtained since the study only includes national register data. The results were analysed and reported on group level.

Competing interests

A-CM was employed by the Sahlgrenska University Hospital and University of Gothenburg when the study was conducted, and is today employed by Novo Nordisk A/S. EL is employed by Nordic Health Economics, a research and consultancy company, and has no competing interests or financial disclosures related to the current study. KAS was employed by the University of Gothenburg when the study was conducted, and is today employed by AstraZeneca AB. The authors’ work was independent from the employers. The authors have no conflict of interest to declare related to the study question or the results presented.

References

  1. 1.
    The National Board of Health and Welfare (2010) Nationella riktlinjer för vård vid depression och ångesyndrom 2010 - stöd för styrning och ledning (In English: National guidelines for the care of depression and anxiety syndroms 2010). StockholmGoogle Scholar
  2. 2.
    National Institute for Health and Clinical Excellence (2009) Depression in adults: the treatment and management of depression in adults. NHSGoogle Scholar
  3. 3.
    Bauer M, Bschor T, Pfennig A, Whybrow P, Angst J, Versiani M, et al. (2007) World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of unipolar depressive disorders in primary care. World J Biol Psychiatry 8:67–104CrossRefPubMedGoogle Scholar
  4. 4.
    National Institute for Health and Care Excellence (2011) Generalised anxiety disorder and panic disorder in adults: management. NHSGoogle Scholar
  5. 5.
    Hansen HV, Kessing LV (2007) Adherence to antidepressant treatment. Expert Rev Neurother 7:57–62. doi: 10.1586/14737175.7.1.57 CrossRefPubMedGoogle Scholar
  6. 6.
    Khandelwal N, Duncan I, Rubinstein E, Ahmed T, Pegus C, Murphy P, et al. (2011) Medication adherence for 90-day quantities of medication dispensed through retail and mail order pharmacies. Am J Manag Care 17:e427–e434PubMedGoogle Scholar
  7. 7.
    Tomasson K, Tomasson H, Zoega T, Sigfusson E, Helgason T (2007) Epidemiology of psychotropic medication use: comparison of sales, prescriptions and survey data in Iceland. Nord J Psychiatry 61:471–478. doi: 10.1080/08039480701773311 CrossRefPubMedGoogle Scholar
  8. 8.
    Sansone RA, Sansone LA (2012) Antidepressant adherence: are patients taking their medications? Innov Clin Neurosci 9:41–46PubMedPubMedCentralGoogle Scholar
  9. 9.
    Hansen RA, Dusetzina SB, Dominik RC, Gaynes BN (2010) Prescription refill records as a screening tool to identify antidepressant non-adherence. Pharmacoepidemiol Drug Saf 19:33–37. doi: 10.1002/pds.1881 CrossRefPubMedPubMedCentralGoogle Scholar
  10. 10.
    Lu CY, Roughead E (2012) New users of antidepressant medications: first episode duration and predictors of discontinuation. Eur J Clin Pharmacol 68:65–71. doi: 10.1007/s00228-011-1087-3 CrossRefPubMedGoogle Scholar
  11. 11.
    Kales HC, Nease DE Jr, Sirey JA, Zivin K, Kim HM, Kavanagh J, et al. (2013) Racial differences in adherence to antidepressant treatment in later life. Am J Geriatr Psychiatry 21:999–1009. doi: 10.1016/j.jagp.2013.01.046 CrossRefPubMedGoogle Scholar
  12. 12.
    Hansen DG, Vach W, Rosholm JU, Sondergaard J, Gram LF, Kragstrup J (2004) Early discontinuation of antidepressants in general practice: association with patient and prescriber characteristics. Fam Pract 21:623–629. doi: 10.1093/fampra/cmh608 CrossRefPubMedGoogle Scholar
  13. 13.
    Sundell KA, Waern M, Petzold M, Gissler M (2013) Socio-economic determinants of early discontinuation of anti-depressant treatment in young adults. Eur J Pub Health 23:433–440. doi: 10.1093/eurpub/ckr137 CrossRefGoogle Scholar
  14. 14.
    Bocquier A, Cortaredona S, Verdoux H, Casanova L, Sciortino V, Nauleau S, et al. (2014) Social inequalities in early antidepressant discontinuation. Psychiatr Serv 65:618–625. doi: 10.1176/appi.ps.201300184 CrossRefPubMedGoogle Scholar
  15. 15.
    Hung CI (2014) Factors predicting adherence to antidepressant treatment. Curr Opin Psychiatry 27:344–349. doi: 10.1097/yco.0000000000000086 CrossRefPubMedGoogle Scholar
  16. 16.
    Bogner HR, Lin JY, Morales KH (2006) Patterns of early adherence to the antidepressant citalopram among older primary care patients: the prospect study. Int J Psychiatry Med 36:103–119CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Maddox TM, Ross C, Tavel HM, Lyons EE, Tillquist M, Ho PM, et al. (2010) Blood pressure trajectories and associations with treatment intensification, medication adherence, and outcomes among newly diagnosed coronary artery disease patients. Circ Cardiovasc Qual Outcomes 3:347–357. doi: 10.1161/circoutcomes.110.957308 CrossRefPubMedPubMedCentralGoogle Scholar
  18. 18.
    Franklin JM, Shrank WH, Pakes J, Sanfelix-Gimeno G, Matlin OS, Brennan TA, et al. (2013) Group-based trajectory models: a new approach to classifying and predicting long-term medication adherence. Med Care 51:789–796. doi: 10.1097/MLR.0b013e3182984c1f CrossRefPubMedGoogle Scholar
  19. 19.
    Lesen E, Sandstrom TZ, Carlsten A, Jonsson AK, Mardby AC, Sundell KA (2011) A comparison of two methods for estimating refill adherence to statins in Sweden: the RARE project. Pharmacoepidemiol Drug Saf 20:1073–1079. doi: 10.1002/pds.2204 CrossRefPubMedGoogle Scholar
  20. 20.
    Jonsson AK, Schioler L, Lesen E, Andersson Sundell K, Mardby AC (2014) Influence of refill adherence method when comparing level of adherence for different dosing regimens. Eur J Clin Pharmacol 70:589–597. doi: 10.1007/s00228-014-1649-2 CrossRefPubMedGoogle Scholar
  21. 21.
    The National Board of Health and Welfare (2009) Pharmaceuticals-statistics for 2008. StockholmGoogle Scholar
  22. 22.
    Wettermark B, Hammar N, Fored CM, Leimanis A, Otterblad Olausson P, Bergman U, et al. (2007) The new Swedish prescribed drug register—opportunities for pharmacoepidemiological research and experience from the first six months. Pharmacoepidemiol Drug Saf 16:726–735. doi: 10.1002/pds.1294 CrossRefPubMedGoogle Scholar
  23. 23.
    Burnett-Zeigler I, Kim HM, Chiang C, Kavanagh J, Zivin K, Rockefeller K, et al. (2014) The association between race and gender, treatment attitudes, and antidepressant treatment adherence. Int J Geriatr Psychiatry 29:169–177. doi: 10.1002/gps.3984 CrossRefPubMedGoogle Scholar
  24. 24.
    Zimmer Z, Martin LG, Jones BL, Nagin DS (2014) Examining late-life functional limitation trajectories and their associations with underlying onset, recovery, and mortality. J Gerontol Ser B Psychol Sci Soc Sci 69:275–286. doi: 10.1093/geronb/gbt099 CrossRefGoogle Scholar
  25. 25.
    Isacsson G, Boethius G, Henriksson S, Jones JK, Bergman U (1999) Selective serotonin reuptake inhibitors have broadened the utilisation of antidepressant treatment in accordance with recommendations. Findings from a Swedish prescription database. J Affect Disord 53:15–22CrossRefPubMedGoogle Scholar
  26. 26.
    Gichangi A, Andersen M, Kragstrup J, Vach W (2006) Analysing duration of episodes of pharmacological care: an example of antidepressant use in Danish general practice. Pharmacoepidemiol Drug Saf 15:167–177. doi: 10.1002/pds.1160 CrossRefPubMedGoogle Scholar
  27. 27.
    Johnell K, Fastbom J (2008) Multi-dose drug dispensing and inappropriate drug use: a nationwide register-based study of over 700,000 elderly. Scand J Prim Health Care 26:86–91. doi: 10.1080/02813430802022196 CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Ann-Charlotte Mårdby
    • 1
    • 2
    • 3
  • Linus Schiöler
    • 4
  • Karolina Andersson Sundell
    • 2
    • 5
  • Pernilla Bjerkeli
    • 6
    • 7
  • Eva Lesén
    • 8
  • Anna K. Jönsson
    • 9
  1. 1.Research and DevelopmentSahlgrenska University HospitalGothenburgSweden
  2. 2.Section of Epidemiology and Social Medicine, Department of Public Health and Community Medicine at Institute of MedicineUniversity of GothenburgGothenburgSweden
  3. 3.Novo Nordisk A/SMalmöSweden
  4. 4.Section of Occupational and Environmental Medicine, Department of Public Health and Community Medicine at Institute of MedicineUniversity of GothenburgGothenburgSweden
  5. 5.Medical Evidence and Observational ResearchMölndalSweden
  6. 6.Nordic School of Public HealthGothenburgSweden
  7. 7.Department for Biomedicine and Public Health ResearchUniversity of SkövdeSkövdeSweden
  8. 8.Nordic Health Economics ABGothenburgSweden
  9. 9.Department of Forensic Genetics and Forensic ToxicologyNational Board of Forensic MedicineLinköpingSweden

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