A method of obtaining data from a patient with respiratory disease, including: recording an EMG para signal during resting breathing and an EMG paramax signal during a maximum sniff manoeuvre; obtaining the root mean square of the EMG para signal to obtain a first rectified parasternal trace (rmsEMG para); obtaining the root mean square of the EMG paramax signal to obtain a second rectified parasternal trace (rmsEMG paramax); calculating the neural respiratory drive (NRD = EMG para%max) by expressing the peak EMG para signal determined from the first rectified parasternal trace obtained in Step 2 as a percentage of the peak EMG paramax signal determined from the second rectified parasternal trace obtained in Step 3 (EMG para%max); obtaining the respiratory rate of the patient, expressed as breaths per minute; obtaining a value for the neural respiratory drive index (NRDI) by multiplying the value of the normalised neural respiratory drive obtained in Step 4 by the respiratory rate; characterised in that the method further comprises: measuring the area under the first rectified parasternal trace (rmsEMG para) to obtain a value for the resting neural respiratory drive time product (NRDTP = EMG paraAUC); obtaining a normalised value for the neural respiratory drive time index (NRDTI) as a percentage by multiplying the resting neural respiratory drive time product (NRDTP) by the respiratory rate and dividing by the maximum area under the curve of the second rectified parasternal trace (EMG paramaxAUC); and repeating Steps 1 to 8 continuously and/or after a first given period of time and comparing the two neural respiratory drive index values and the two neural respiratory drive time index values obtained. recording an EMG para signal during resting breathing and an EMG paramax signal during a maximum sniff manoeuvre; obtaining the root mean square of the EMG para signal to obtain a first rectified parasternal trace (rmsEMG para); obtaining the root mean square of the EMG paramax signal to obtain a second rectified parasternal trace (rmsEMG paramax); calculating the neural respiratory drive (NRD = EMG para%max) by expressing the peak EMG para signal determined from the first rectified parasternal trace obtained in Step 2 as a percentage of the peak EMG paramax signal determined from the second rectified parasternal trace obtained in Step 3 (EMG para%max); obtaining the respiratory rate of the patient, expressed as breaths per minute; obtaining a value for the neural respiratory drive index (NRDI) by multiplying the value of the normalised neural respiratory drive obtained in Step 4 by the respiratory rate; measuring the area under the first rectified parasternal trace (rmsEMG para) to obtain a value for the resting neural respiratory drive time product (NRDTP = EMG paraAUC); obtaining a normalised value for the neural respiratory drive time index (NRDTI) as a percentage by multiplying the resting neural respiratory drive time product (NRDTP) by the respiratory rate and dividing by the maximum area under the curve of the second rectified parasternal trace (EMG paramaxAUC); and repeating Steps 1 to 8 continuously and/or after a first given period of time and comparing the two neural respiratory drive index values and the two neural respiratory drive time index values obtained.