Background:
Freely available and easily accessible (e.g. via the internet) written consumer health information (CHI) plays an increasingly important role in the treatment decision process between patients and their health-care professionals. Criteria describing the quality of CHI have already been defined. However, there is criticism that they are not yet comprehensively addressed within existing CHI. This study aims at assessing the quality of written CHI about treatment options for chronic myeloid leukaemia (CML).

Methods:
Written CHI material was identified by an internet search in three search engines. In addition, organisations (n=118) potentially offering written CHI on CML, were directly contacted and asked to provide their patient information material. Furthermore, their websites were screened for relevant material. The structural quality of the included material was assessed with the standardised quality appraisal instrument DISCERN by two independent raters.

Results:
33 patient information sources on CML and its treatment options were included. The overall mean DISCERN rating (absolute rating based on questions 1-15: min 15 to max 75) was 44.12 (range 24 to 65, SD 11.49) and the overall mean DISCERN score (mean rating based on questions 1-15: min 1 to max 5) was 2.94 (SD 0.766). Mean DISCERN scores show a statistically significant discrepancy in quality of the material between the different types of information providers (p=0.012), but not between providers presenting a quality certification on their website and those without a quality label (p=0.385).

Conclusion:
These results confirm that available CHI does not sufficiently meet existing quality criteria for patient information. Especially material offered by commercial organisations has significantly lower DISCERN ratings than that offered by non-profit organisations. Astonishingly, the material of providers approved by quality labels such as Health-on-the-Net (HON), which claim to set apart trustworthy from non-trustworthy websites (e.g. potential for commercial influence), does not demonstrate higher quality than material by providers without any quality labels.