Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015): An Interrupted Time-Series Study Using Latent Curve Models

Ronald D. McDowell; Kathleen Bennett; Frank Moriarty; Sarah Clarke; Michael Barry; Tom Fahey

doi:10.1177/0272989X18818165

Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015): An Interrupted Time-Series Study Using Latent Curve Models

Ronald D. McDowell
, Kathleen Bennett
, Frank Moriarty
, Sarah Clarke
, Michael Barry
, Tom Fahey

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

Objectives. To examine the impact of the Preferred Drugs Initiative (PDI), an Irish health policy aimed at reducing prescribing variation. Design. Interrupted time series spanning 2012 to 2015. Setting. Health Service Executive pharmacy claims data for General Medical Services (GMS) patients, approximately 40% of the Irish population. Participants. Prescribers issuing preferred drug group items to GMS adults before and after PDI guidelines. Primary Outcome. The percentage coverage of PDI medications within each drug class per calendar quarter per prescriber. Methods. Latent curve models with structured residuals (LCM-SRs) were used to model coverage of the preferred drugs over time. The number of GMS adults receiving medication and the percentage who were 65 years and older at the start of the study were included as covariates. Results. In the quarter following PDI guidelines, coverage of the preferred drugs increased most in absolute terms for proton pump inhibitors (PPIs) (1.50% [SE 0.15], P < 0.001) and selective and norepinephrine reuptake inhibitors (SNRIs) (1.17% [SE 0.26], P < 0.001). Variation between prescribers remained relatively unchanged and increased for urology medications. Prescribers who increased coverage of the preferred PPI also increased coverage of the preferred statin immediately following guidelines (correlation 0.47 [SE 0.13], P < 0.001). Where guidelines were disseminated simultaneously, coverage of one preferred drug did not significantly predict coverage of the other preferred drug in the next calendar quarter. Prescribing of preferred drugs was not moderated by prescriber-level factors. Conclusions. Modest changes in prescribing of the preferred drugs have been observed over the course of the PDI. However, the guidelines have had little impact in reducing variation between prescribers. Further strategies may be necessary to reduce variation in clinical practice and enhance patient care.

Original language	English
Pages (from-to)	278-293
Number of pages	16
Journal	Medical Decision Making
Volume	39
Issue number	3
DOIs	https://doi.org/10.1177/0272989X18818165
Publication status	Published (in print/issue) - 1 Apr 2019

Bibliographical note

Publisher Copyright:
© The Author(s) 2019.

Funding

Health Research Board (HRB) Centre for Primary Care Research, Department of General Practice, Royal College of Surgeons in Ireland Medical School, Dublin 2, Ireland (RM, FM, TF); Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen’s University, Belfast, UK (RM); Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin 2, Ireland (KB); Health Service Executive Medicines Management Programme, Trinity Centre for Health Sciences, St. James’s Hospital, Dublin 8, Ireland (SC); and National Centre for Pharmacoeconomics, Trinity Centre for Health Sciences, St. James’s Hospital, Dublin 8, Ireland (MB). The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Financial support for this study was provided entirely by a grant from the HRB of Ireland under the HRB Centre for Primary Care Phase 2 Funding award, grant HRC/2014/1 (RM, FM, TF) and grant RL-15-1579 (KB). The funding agreement ensured the authors’ independence in designing the study, interpreting the data, writing, and publishing the report.

Funder number
RL-15-1579, HRC/2014/1

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 3 Good Health and Well-being

Keywords

growth curves
interrupted time series
medical practice variation

Access to Document

10.1177/0272989X18818165

Cite this

@article{e6b538412e9b4d27863f86212f7bb1b1,

title = "Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015): An Interrupted Time-Series Study Using Latent Curve Models",

abstract = "Objectives. To examine the impact of the Preferred Drugs Initiative (PDI), an Irish health policy aimed at reducing prescribing variation. Design. Interrupted time series spanning 2012 to 2015. Setting. Health Service Executive pharmacy claims data for General Medical Services (GMS) patients, approximately 40\% of the Irish population. Participants. Prescribers issuing preferred drug group items to GMS adults before and after PDI guidelines. Primary Outcome. The percentage coverage of PDI medications within each drug class per calendar quarter per prescriber. Methods. Latent curve models with structured residuals (LCM-SRs) were used to model coverage of the preferred drugs over time. The number of GMS adults receiving medication and the percentage who were 65 years and older at the start of the study were included as covariates. Results. In the quarter following PDI guidelines, coverage of the preferred drugs increased most in absolute terms for proton pump inhibitors (PPIs) (1.50\% [SE 0.15], P < 0.001) and selective and norepinephrine reuptake inhibitors (SNRIs) (1.17\% [SE 0.26], P < 0.001). Variation between prescribers remained relatively unchanged and increased for urology medications. Prescribers who increased coverage of the preferred PPI also increased coverage of the preferred statin immediately following guidelines (correlation 0.47 [SE 0.13], P < 0.001). Where guidelines were disseminated simultaneously, coverage of one preferred drug did not significantly predict coverage of the other preferred drug in the next calendar quarter. Prescribing of preferred drugs was not moderated by prescriber-level factors. Conclusions. Modest changes in prescribing of the preferred drugs have been observed over the course of the PDI. However, the guidelines have had little impact in reducing variation between prescribers. Further strategies may be necessary to reduce variation in clinical practice and enhance patient care.",

keywords = "growth curves, interrupted time series, medical practice variation",

author = "McDowell, \{Ronald D.\} and Kathleen Bennett and Frank Moriarty and Sarah Clarke and Michael Barry and Tom Fahey",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2019.",

year = "2019",

month = apr,

day = "1",

doi = "10.1177/0272989X18818165",

language = "English",

volume = "39",

pages = "278--293",

journal = "Medical Decision Making",

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Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015): An Interrupted Time-Series Study Using Latent Curve Models. / McDowell, Ronald D.; Bennett, Kathleen; Moriarty, Frank et al.
In: Medical Decision Making, Vol. 39, No. 3, 01.04.2019, p. 278-293.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015)

T2 - An Interrupted Time-Series Study Using Latent Curve Models

AU - McDowell, Ronald D.

AU - Bennett, Kathleen

AU - Moriarty, Frank

AU - Clarke, Sarah

AU - Barry, Michael

AU - Fahey, Tom

PY - 2019/4/1

Y1 - 2019/4/1

N2 - Objectives. To examine the impact of the Preferred Drugs Initiative (PDI), an Irish health policy aimed at reducing prescribing variation. Design. Interrupted time series spanning 2012 to 2015. Setting. Health Service Executive pharmacy claims data for General Medical Services (GMS) patients, approximately 40% of the Irish population. Participants. Prescribers issuing preferred drug group items to GMS adults before and after PDI guidelines. Primary Outcome. The percentage coverage of PDI medications within each drug class per calendar quarter per prescriber. Methods. Latent curve models with structured residuals (LCM-SRs) were used to model coverage of the preferred drugs over time. The number of GMS adults receiving medication and the percentage who were 65 years and older at the start of the study were included as covariates. Results. In the quarter following PDI guidelines, coverage of the preferred drugs increased most in absolute terms for proton pump inhibitors (PPIs) (1.50% [SE 0.15], P < 0.001) and selective and norepinephrine reuptake inhibitors (SNRIs) (1.17% [SE 0.26], P < 0.001). Variation between prescribers remained relatively unchanged and increased for urology medications. Prescribers who increased coverage of the preferred PPI also increased coverage of the preferred statin immediately following guidelines (correlation 0.47 [SE 0.13], P < 0.001). Where guidelines were disseminated simultaneously, coverage of one preferred drug did not significantly predict coverage of the other preferred drug in the next calendar quarter. Prescribing of preferred drugs was not moderated by prescriber-level factors. Conclusions. Modest changes in prescribing of the preferred drugs have been observed over the course of the PDI. However, the guidelines have had little impact in reducing variation between prescribers. Further strategies may be necessary to reduce variation in clinical practice and enhance patient care.

AB - Objectives. To examine the impact of the Preferred Drugs Initiative (PDI), an Irish health policy aimed at reducing prescribing variation. Design. Interrupted time series spanning 2012 to 2015. Setting. Health Service Executive pharmacy claims data for General Medical Services (GMS) patients, approximately 40% of the Irish population. Participants. Prescribers issuing preferred drug group items to GMS adults before and after PDI guidelines. Primary Outcome. The percentage coverage of PDI medications within each drug class per calendar quarter per prescriber. Methods. Latent curve models with structured residuals (LCM-SRs) were used to model coverage of the preferred drugs over time. The number of GMS adults receiving medication and the percentage who were 65 years and older at the start of the study were included as covariates. Results. In the quarter following PDI guidelines, coverage of the preferred drugs increased most in absolute terms for proton pump inhibitors (PPIs) (1.50% [SE 0.15], P < 0.001) and selective and norepinephrine reuptake inhibitors (SNRIs) (1.17% [SE 0.26], P < 0.001). Variation between prescribers remained relatively unchanged and increased for urology medications. Prescribers who increased coverage of the preferred PPI also increased coverage of the preferred statin immediately following guidelines (correlation 0.47 [SE 0.13], P < 0.001). Where guidelines were disseminated simultaneously, coverage of one preferred drug did not significantly predict coverage of the other preferred drug in the next calendar quarter. Prescribing of preferred drugs was not moderated by prescriber-level factors. Conclusions. Modest changes in prescribing of the preferred drugs have been observed over the course of the PDI. However, the guidelines have had little impact in reducing variation between prescribers. Further strategies may be necessary to reduce variation in clinical practice and enhance patient care.

KW - growth curves

KW - interrupted time series

KW - medical practice variation

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DO - 10.1177/0272989X18818165

M3 - Article

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AN - SCOPUS:85061578349

SN - 0272-989X

VL - 39

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JO - Medical Decision Making

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ER -

Prescriber Variation in Relation to Prescribing Trends within the Preferred Drugs Initiative in Ireland (2012–2015): An Interrupted Time-Series Study Using Latent Curve Models

Abstract

Bibliographical note

Funding

UN SDGs

Keywords

Access to Document

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