Review: PPRNs in relative effectiveness research, plus a survey of key stakeholders

What is it?

The usefulness of PPRNs as a source of data for relative or comparative effectiveness research (CER) and the views of key decision makers using health research are unclear.

For a description of PPRNs, a summary of their benefits and limitations and some examples of PPRNs, see Patient-Powered Research Networks.

A review of PPRNs was commissioned by GetReal to explore these issues. The overall objectives were to:

  • Understand available PPRNs and classify them based on their suitability for use in CER.
  • Demonstrate the potential usefulness of PPRNs (especially PCORnet for CER to regulators, health technology assessment (HTA) agencies and payers for evaluating comparative effectiveness of products by:
    • showcasing successful examples of generation of comparative effectiveness data (if any) on licensed products
    • identifying any disease areas for which PPRNs are particularly useful
    • understanding the limitations and practical feasibility of using PPRNs for CER
  • Assess the level of acceptability of PPRNs to regulators, HTA agencies and payers for measuring relative effectiveness.
  • Review the potential future role of PPRNs in effectiveness research (over an approximate 10 year time horizon) and any implications for effectiveness research in general in Europe.
  • Understand the potential impact of PPRNs on patients and patients’ views of PPRNs.

What was examined in this case study?

The following approaches were used to address the objectives:

  • Pragmatic literature review: to provide an overview of recent publications on PPRNs, identified through Medline, EMBASE and Google Scholar.
  • Desktop research: to identify existing PPRNs and assess them for their suitability for CER. Suitability was determined using characteristics relevant to CER such as source of data, medicine, outcomes and potential covariates and an overall scoring system was developed.
  • Survey of key decision makers and key opinion leaders: to assess the usefulness and acceptability of PPRNs for CER using phone interviews.

See more details on methods in this GetReal presentation on Patient-Powered Research Networks for Relative Effectiveness Research

Abbreviations: KOI – Key opinion leaders

What were the findings and conclusions?

Pragmatic literature review

  • 18 publications were identified, most of which reported views or opinions; one study used PPRN data for CER.
  • An example of a PPRN used successfully for CER was identified for amyotrophic lateral sclerosis, in which PatientsLikeMe built a tool to collect data for people taking lithium off-label. The study prompted scientific debate on how patient-reported data can contribute to neurological research.
  • Thematic analysis extracted 15 themes related to future use, and 33 quotes related to potential challenges.
  • There is ongoing debate in the literature about standardising and harmonising patient-reported outcome data as well as electronic health record (EHR) data for CER. Views on PPRN data for CER are positive but approached with caution.

Desktop research

  • 33 PPRNs were identified; four were European but most were from the US and funded by the Patient-Centered Outcomes Research Institute (PCORI). 3 PPRNs were excluded because their websites were not considered accessible.
  • The PPRNs covered a wide range of diseases but most covered any or multiple diseases, or diseases of the nervous system.
  • Adequacy of PPRNs for CER:
    • 7% (2/30) were considered adequate for CER.
    • All collected patient-reported data but only some use EHR data; not using EHR may prevent CER when outcomes are clinical measures
    • All collected current treatments, outcomes, and demographics (essential for CER)
    • Dosage and frequency of pharmacological treatment, medication adherence and co-morbidities are inconsistently collected
  • More aspects of drug exposure and covariates collected in PPRNs would increase usefulness of PPRN data.
  • Non-PCORI PPRNs had higher scores than PCOR PPRNs – this was surprising since PCOR funds PPRNs based on their potential use in CER.


  • Few healthcare decision makers were aware of PPRNs but all key opinion leaders were.
  • Most participants thought PPRNs could be useful for effectiveness research but their views were inconsistent.
  • Most healthcare decision makers thought PPRNs were acceptable for making healthcare decisions, but many provided caveats or limitations.
  • Key obstacles were felt to be the burden around ethics and regulation, the lack of systematic or standardised data collection, and validation of self-reported data.
  • PPRNs using EHRs were felt to be most useful, although few of these exist (36% of PPRNs identified from desktop research used EHRs).

What were the recommendations made?

  • Increase awareness and use of PPRNs by decision makers: the survey showed that healthcare decision makers may find value in existing PPRN data, particularly related to the subjective patient experience of their disease and treatment, but they may not be aware of these data.
  • Increase access to EHRs: access to EHRs was felt to enable PPRNs to be most useful, but few have access to EHR. It is important for PPRNs in development to gain access to EHRs.
  • Improving current PPRNs could improve their ability to generate more useful data for CER: having both EHR and patient-reported outcomes from current PPRNs could enable PPRNs to generate more useful data for CER.

What are the limitations?

Pragmatic literature review

  • The literature is likely to change: only a limited number of publications were identified, which may be because most PPRNs were launched recently. The number of publications reporting on PPRNs is likely to increase in the future.
  • Not all PPRNs may have been identified: PPRNs may have been missed by the search because of the lack of a consistent term for PPRNs and because the search was conducted in English.
  • Potentially biased reporting: most of the literature was from proponents of PPRNs, which could have provided a biased review in the thematic analysis and underrepresentation of negative themes.

Desktop research

  • Not all PPRNs may have been identified: as with the literature search, the lack of consistent terminology and searching only in English means that some PPRNs may have been missed.
  • Missing data prevented categorisation: some PPRNs had missing information so could not be characterised accurately.


  • Location of interviewees: all decision-makers were based on the UK, where PPRNs are less well known. Most key opinion leaders were based in the US where many PPRNs are based.
  • Potential bias in key opinion leaders: most key opinion leaders have a special interest in PPRNs or have conducted research into PPRNs. This gives them additional insights, but they may also have a particularly favourable view of them.