Around one in five hospital outpatient appointments were unattended in England last year, new data has revealed.
The figure is up on a decade ago, when the number was closer to one in six.
Of the 21% of appointments that were unattended in 2016/17, roughly a third were due to patients not turning up.
Cancellations by hospitals and patients each accounted for another third.
By contrast, in 2006/07 almost half of all unattended appointments were due to people not turning up.
The figures, from NHS Digital, also show that the total number of outpatient appointments has nearly doubled since 2006-07, rising from 63.2 million appointments to 118.6 million in 2016-17.