Impact of EU label changes for systemic diclofenac products: post-referral prescribing trends

Study type

• Study topic:
  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Drug utilisation

  Effectiveness study (incl. comparative)
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Other
• Non-interventional study design, other:
  Population-based longitudinal study, Time series analysis

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  DICLOFENAC POTASSIUM

  DICLOFENAC SODIUM

Population studied

• Short description of the study population:
  All patients registered within each data source at any time during the study period who discontinued diclofenac-containing medical products covering the regulatory intervention in June 2013.
• Age groups:
  Term newborn infants (0 – 27 days)

  Infants and toddlers (28 days – 23 months)

  Children (2 to < 12 years)

  Adolescents (12 to < 18 years)

  Adults (18 to < 46 years)

  Adults (46 to < 65 years)

  Adults (65 to < 75 years)

  Adults (75 to < 85 years)

  Adults (85 years and over)
• Estimated number of subjects:
  1000000

Study design details

• Main study objective:
  Three main objectives as follows: To determine prescription patterns of diclofenac containing products. To determine prescribers compliance with cardiovascular contraindications and risk factors. To determine prescription patterns of alternative medicines prescribed in patient where diclofenac has previously been prescribed.
• Data analysis plan:
  In order to determine prescription patterns of diclofenac containing product, prescribers' compliance with cardiovascular contra-indications and risk factors and prescription patterns of alternative medicines prescribed in patients where diclofenac has previously been prescribed, the proposed primary analysis will use interrupted time series regression to fit time trends to each series of time period data (based on quarterly time periods)for each country.Using regression modelling we will evaluate:(I)the baseline slope before the regulatory intervention time point (ii)the change in slope from the baseline trend to the post-intervention trend, and (iii) the immediate change associated with the regulatory intervention time point. The choice of analytical technique will be decided based on visual inspection of the data. The analysis will be done by data source initially, and only pooled if the statistical models do not differ significantly between data sources.