Measurement properties of the tests reviewed
| Main variables | Practice test needed | Standardisation | MCID | Reproducibility | |
| IET | V′O2peak, WRpeak and V′E–V′CO2 indices | No | Adjusting WR increments to the patient capacity Criteria for “good effort” | No Suggested targets in PAH: V′O2 >10 L·min−1·kg−1 V′E–V′CO2 slope <45 | V′O2peak 5–10% WRpeak 5–10% V′E–V′CO2 indices ±2.3 both within and between individuals |
| CWRET | tLIM, isotime IC and isotime dyspnoea | No | Intensity of baseline tests to attain tLIM between 180 and 480 s recommended to reduce variability Pedalling rate Criteria to terminate the test | 105 s or 33% Bronchodilator trials suggest that clinical outcomes improve with increases >60 s | tLIM: 5–10% within individuals 23.7% between individuals |
| ISWT | Time/distance, dysponea and SpO2 | Yes | Audio signal | 47 m | NA |
| ESWT | Time/distance, dyspnoea and SpO2 | Yes | Audio signal Optimum intensity/duration of baseline test yet to be defined | Time 56–71 s Distance 72–81 m | Time −7±72 s Distance −7±113 m both within individuals |
| 6MWT | Distance/SpO2 and dyspnoea | Yes | Track length Encouragement | 25–33 m In PAH, MCID relates to symptom amelioration, but not to survival | Distance 5–8% when performed twice within individuals |
MCID: minimal clinically important difference; IET: incremental exercise test; CWRET: constant work-rate exercise test; ISWT: incremental shuttle walk test; ESWT: endurance shuttle walk test; 6MWT: standardised 6-min walk test; V′O2peak: peak oxygen uptake; WRpeak: peak work-rate (or peak power); V′E–V′CO2: ventilation–carbon dioxide output indices; WR: work-rate; PAH: pulmonary arterial hypertension; V′O2: oxygen uptake; tLIM: tme to the limit of tolerance, typically for constant work-rate tests; IC: inspiratory capacity; SpO2: arterial blood oxygen saturation measured by pulse oximetry; NA: not applicable.