Health Technology Assessment (HTA) reports may have a major impact on the health care provided in a country. Hence, one would assume that these reports have a high methodological quality and thus represent a potentially important source of information, for instance, for identifying primary studies for inclusion in the evidence syntheses (for example, systematic reviews, Cochrane reviews, HTA reports). The aim of the present analysis is to evaluate the methodological quality of HTA reports used as a literature source for HTA reports produced by the German Institute for Quality and Efficiency in Health Care (IQWiG).

Eligible IQWiG reports were assessments of drug or non-drug interventions considering HTA reports as the literature source for primary studies and published up to October 2016. An HTA report included in the IQWIG report was considered in the analysis if it was a complete report published in English or German and indexed in the Health Technology Assessment Database (Wiley) or MEDLINE. Only the most current HTA report in an IQWiG report was considered; if more than one current HTA report was available, the one for inclusion in the analysis was randomly selected. The methodological quality of the HTA reports identified was evaluated with the AMSTAR (“Assessment of Multiple Systematic Reviews”) tool (1), which comprises 11 items on methodological quality (meaning a maximum achievable score of 11).

A total of fifty eligible IQWiG reports using fourty-one eligible HTA reports as literature sources were identified. The mean AMSTAR score of these HTA reports was 5.3 (95 percent Confidence Interval, CI: 4.3, 6.2). None of the HTA reports achieved a score of 11, nineteen (46 percent) had a score between 6 and 10, and twenty-two had a score below 6.

HTA reports included in IQWiG reports only have an average methodological quality.