CONCLUSION
Despite growing interest in evaluating the outcomes of LTOT, there is no
harmonised terminology or gold standard definition of LTOT in
observational research using routinely collected data. The most common
threshold applied was 90 days of supply or use within a year.
Definitions were often based on those used in prior research and less
often on empirical data, with few studies reporting results according to
more than one definition. The appropriateness of definitions employed
should be driven by the study aims, the data available, and the
strengths and limitations of each measure. Researchers should also
consider improving the quality of reporting to allow research
transparency, reproducibility, and comparability of findings.
ACKNOWLEDGEMENTS: This research is supported by the National Health and
Medical Research Council (NHMRC) Centre of Research Excellence in
Medicines and Ageing (ID: 1060407) and a Cooperative Research Centre
Project (CRC-P) Grant from the Australian Government Department of
Industry, Innovation and Science (ID: CRC-P-439). LD is supported by an
Australian National Health and Medical Research Council Senior Principal
Research Fellowship (APP1135991) and by a US National Institutes of
Health grant (R01 DA144740 PI: Degenhardt). The National Drug and
Alcohol Research Centre is supported by funding from the Australian
Government Department of Health under the Drug and Alcohol Program.
CONFLICTS OF INTEREST: The authors report no actual, potential,
or perceived conflict of interest with regards to the submission of this
manuscript. The Centre for Big Data Research in Health, UNSW Sydney has
received funding from AbbVie to conduct research, unrelated to the
present study. Allergan did not have any knowledge of, or involvement
in, the present study. LD has received untied educational grant funding
from Indivior, Mundipharma, Seqirus and Reckitt Benckiser to examine new
opioid medications in Australia. These companies had no knowledge of
this review.