↵* For some aspects of construct validity only (association between pericardial effusion and mortality, tricuspid regurgitant jet velocity, and dyspnea). V: valid: A criterion was judged validated if appropriate information was available from studies including exclusively PAH-SSc patients (quality definition A1, see Table 1). Exception is face validity, which is evaluated by the judgement of experts as an appropriate measure rather than by specific studies. NV: not valid: Similarly, a criterion was judged not valid if appropriate information was available from studies including exclusively PAH-SSc patients (quality definition A1). PV: partially validated: A criterion was judged partially validated if data from studies lower than quality level A1 indicated that the criterion was validated. U: unclear, possibly not valid: A criterion was judged unclear/possibly not valid if data from studies lower than quality level A1 indicated that the criterion was not valid. NA: not applicable; ND: no data.