International Journal of Clinical Pharmacy

, Volume 40, Issue 6, pp 1559–1567 | Cite as

Confidence and accuracy in identification of adverse drug reactions reported by outpatients

  • Sirinya Kampichit
  • Thongchai Pratipanawatr
  • Narumol JarernsiripornkulEmail author
Research Article


Background Patient reporting of adverse drug reactions (ADRs) could supplement the existing reporting system and contribute to early detection of ADRs. The confidence in ADR identification and their attribution of ADRs were limited to outpatients. Objective To determine the type and frequency of ADRs reported by outpatients, to evaluate confidence and accuracy in ADR identification as well as contributing factors. Setting University hospital in northeastern Thailand Method Cross-sectional study using questionnaires distributed to 500 outpatients who claimed to have experienced an ADR. Confidence in identifying ADRs was measured by visual analogue score (VAS), while accuracy of reported ADRs was determined using Naranjo algorithm and WHO criteria. Main outcome measure Number and type of ADRs, confidence rating and accuracy category. Results In total, 390 outpatients completed the questionnaire (response rate = 78.0%). Rash (19.0%), nausea/vomiting (7.4%), and dizziness (5.8%) were the top three reported ADRs. Sixty-one percent of respondents rated their level of confidence in identifying ADRs as high (VAS 9.2 ± 0.95), which was associated with having underlying diseases (OR 1.93), low number of reported symptoms (OR 0.38) and severe ADRs (OR 1.33). Causality assessment was classified as true ADRs in 90.0% and 88.9% of cases, using Naranjo algorithm and WHO criteria, respectively. Respondents with low number of reported symptoms (OR 0.27) and high level of confidence had greater accuracy in ADR identification (OR 1.11). Conclusion The outpatients reported a high proportion of potential ADRs with high confidence and accuracy. Patient reporting of ADRs has potential to support the pharmacovigilance system.


Accuracy Adverse drug reactions Confidence Patient reporting Related factors Thailand 



The authors thank the patients for their participation and the staff at Srinagarind Hospital for their assistance.


This study received financial support from Graduate School, Khon Kaen University (Grant Number 59121109). The funding organization had no role in the design or conducting of the study.

Conflicts of interest

None of authors declared any conflict of interest.


  1. 1.
    Langerova P, Vrtal J, Urbanek K. Adverse drug reactions causing hospital admissions in childhood: a prospective, observational, single-centre study. Basic Clin Pharmacol Toxicol. 2014;115:560–4.CrossRefGoogle Scholar
  2. 2.
    Khan LM, Al-Harthi SE, Osman AM, Sattar MA, Ali AS. Dilemmas of the causality assessment tools in the diagnosis of adverse drug reactions. Saudi Pharm J. 2015;24:485–93.CrossRefGoogle Scholar
  3. 3.
    Blenkinsopp A, Wilkie P, Wang M, Routledge PA. Patient reporting of suspected adverse drug reactions: a review of published literature and international experience. Br J Clin Pharmacol. 2007;63:148–56.CrossRefGoogle Scholar
  4. 4.
    Hazell L, Shakir SA. Under-reporting of adverse drug reactions: a systematic review. Drug Saf. 2006;29:385–96.CrossRefGoogle Scholar
  5. 5.
    Irujo M, Beitia G, Bes-Rastrollo M, Figueiras A, Hernández-Díaz S, Lasheras B. Factors that influence under-reporting of suspected adverse drug reactions among community pharmacists in a Spanish region. Drug Saf. 2007;30:1073–82.CrossRefGoogle Scholar
  6. 6.
    Chaipichit N, Krska J, Pratiparnwat T, Uchaipichat V, Jarernsiripornkul N. A qualitative study to explore how patients identify and assess symptoms as adverse drug reactions. Eur J Clin Pharmacol. 2014;70:607–15.CrossRefGoogle Scholar
  7. 7.
    McLernon DJ, Bond CM, Hannaford PC, Watson MC, Lee AJ, Hazell L. Yellow Card Collaboration. Adverse drug reaction reporting in the UK: a retrospective observational comparison of yellow card reports submitted by patients and healthcare professionals. Drug Saf. 2010;33:775–88.CrossRefGoogle Scholar
  8. 8.
    Agbabiaka TB, Savovic J, Ernst E. Methodos for causality assessment of adverse drug reactions. Drug Saf. 2008;31:21–37.CrossRefGoogle Scholar
  9. 9.
    Gäwert L, Hierse F, Zink A, Strangfeld A. How well do patient reports reflect adverse drug reactions reported by rheumatologists? Agreement of physician- and patient-reported adverse events in patients with rheumatoid arthritis observed in the German biologics register. Rheumatology (Oxford). 2011;50:152–60.CrossRefGoogle Scholar
  10. 10.
    Ramakrishnaiah H, Naidu S, Jyothsnya S. A comparative study of adverse drug reactionsnreported by healthcare professional and patients in tertiary care teaching hospital. Int J Basic Clin Pharmacol. 2017;6:1078.CrossRefGoogle Scholar
  11. 11.
    Jarernsiripornkul N, Senacom P, Uchaipichat V, Chaipichit N, Krska J. Patient reporting of suspected adverse drug reaction to antiepileptic drugs: factors affecting attribution accuracy. Epilepsy Behav. 2012;24:102–6.CrossRefGoogle Scholar
  12. 12.
    Jarernsiripornkul N, Chaisrisawadsuk S, Chaiyakum A, Krska J. Patient self-reporting of potential adverse drug reactions to non-steroidal anti-inflammatory drugs in Thailand. Pharm World Sci. 2009;31:559–64.CrossRefGoogle Scholar
  13. 13.
    Jarernsiripornkul N, Kakaew W, Loalukkana W, Krska J. Adverse drug reaction monitoring: comparing doctor and patient reporting for new drugs. Pharmacoepidemiol Drug Saf. 2009;18:240–5.CrossRefGoogle Scholar
  14. 14.
    Jarernsiripornkul N, Krska J, Richards ME, Capps PAG. Patient reporting of adverse drug reactions: useful information for pain management? Eur J Pain. 2003;7:219–24.CrossRefGoogle Scholar
  15. 15.
    Van Den Bemt PM, Egberts AC, Lenderink AW, Verzijl JM, Simons KA, Van Der Pol WS, et al. Adverse drug events in hospitalized patients. A comparison of doctors, nurses and patients as sources of reports. Eur J Clin Pharmacol. 1999;55:155–8.CrossRefGoogle Scholar
  16. 16.
    Fisher S, Bryant SG. Postmarketing surveillance: accuracy of patient drug attribution judgments. Clin Pharmacol Ther. 1990;48:102–7.CrossRefGoogle Scholar
  17. 17.
    Tangiisuran B, Wright J, Van der Cammen T, Rajkumari C. Adverse drug reactions in elderly: challenges in identification and improving preventative strategies. Age Ageing. 2009;38:358–9.CrossRefGoogle Scholar
  18. 18.
    Jarernsiripornkul N, Patsuree A, Krska J. Public confidence in ADR identification and their views on ADR reporting: mixed method study. Eur J Clin Pharmacol. 2017;73:223–31.CrossRefGoogle Scholar
  19. 19.
    Jarernsiripornkul N, Krska J, Capps PAG, Richards ME, Lee A. Patient reporting of potential adverse drug reaction: a methodological study. Br J Clin Pharmacol. 2002;53:318–25.CrossRefGoogle Scholar
  20. 20.
    Jarernsiripornkul N, Chaipichit N, Pratipanawatr T, Uchaipichat V. Initial development and testing of an instrument for patient self-assessment of adverse drug reactions. Pharmacoepidemiol Drug Saf. 2016;25:54–63.CrossRefGoogle Scholar
  21. 21.
    Turner RC, Carlson L. Indexes of item-objective congruence for multidimensional items. Int J Test. 2009;3:163–71.CrossRefGoogle Scholar
  22. 22.
    Naranjo CA, Busto U, Sellers EM, Sandor P, Ruiz I, Roberts EA, et al. A method for estimating the probability of adverse drug reactions. Clin Pharmacol Ther. 1981;30:239–45.CrossRefGoogle Scholar
  23. 23.
    The Uppsala Monitoring Centre. The use of the WHO-UMC system for standardizes case causality assessment. Accessed 20 Mar 2018.
  24. 24.
    Chaipichit N, Jarernsiripornkul N, Uchaipichit V, Pratiparnwat T, Krska J. Patients’ attitude towards self-reporting of adverse drug reactions. Srinagarind Med J. 2014;29:461–8.Google Scholar
  25. 25.
    van Hunsel F, van der Welle C, Passier A, van Puijenbroek E, Grootheest K. Motives for reporting adverse drug reactions by patient-reporters in the Netherlands. Eur J Clin Pharmacol. 2010;66:1143–50.CrossRefGoogle Scholar
  26. 26.
    Jarernsiripornkul N, Arunrot P, Krska J. Survey of patients’ experiences and their certainty of suspected adverse drug reactions. Int J Clin Pharm. 2015;37:168–74.CrossRefGoogle Scholar
  27. 27.
    Isacson D, Johansson L, Bingefors K. Nationwide survey of subjectively reported adverse drug reactions in Sweden. Ann Pharmacother. 2008;42:347–53.CrossRefGoogle Scholar
  28. 28.
    Parretta E, Rafaniello C, Magro L, Coggiola Pittoni A, Sportiello L, Ferrajolo C, et al. Improvement of patient adverse drug reaction reporting through a community pharmacist-based intervention in the Campania region of Italy. Expert Opin Drug Saf. 2014;13:21–9.CrossRefGoogle Scholar
  29. 29.
    Center Health Product Vigilance. Adverse drug reactions reporting 2015. Thai Food and Drug Administration, Ministry of Public Health. 2015. Accessed 20 Mar 2018.
  30. 30.
    Banovac M, Candore G, Slattery J, Houyez F, Haerry D, Genov G, et al. Patient reporting in the EU: analysis of EudraVigilance data. Drug Saf. 2017;40:629–45.CrossRefGoogle Scholar
  31. 31.
    Matos C, van Hunsel F, Joaquin J. Are consumers ready to take part in the pharmacovigilance system? A Portuguese preliminary study concerning ADR reporting. Eur J Clin Pharmacol. 2015;71:883–90.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Division of Clinical Pharmacy, Faculty of Pharmaceutical SciencesKhon Kaen UniversityKhon KaenThailand
  2. 2.Department of Medicine, Faculty of MedicineKhon Kaen UniversityKhon KaenThailand

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