26 July 2007
RESPONSE TO LETTER TO THE EDITOR (DELANEY, WEBB AND FORSYTHE)
I thank Delaney, Webb and Forsythe for their comments. The report was not of a distinct cohort followed for 2 years but of children seen and managed in community practice.1 As we noted most other studies are from scientific institutions rather than the community where most practice.
Five hundred and five children were seen in the 5-year study period 1997–2002. Within this period 368 of the 399 achieving initial dryness had reached 6 months from initial management of whom 270 had remained continuously dry for 6 months. Thirty-one of those 399 achieving initial dryness were seen within the last 6 months of the study period. Within this 5-year period 266 of the 399 achieving initial dryness had reached 24 months from initial management of which 171 had remained continuously dry for 24 months. Of the 399, 133 were seen within the last 2-year period.
The subsequent outcomes of those not achieving initial success or relapsing are not completely known, however, many returned for later trial of the alarm, and some may have sought management elsewhere.
Delaney et al. are technically correct in their statistical analysis of our group as a scientific cohort.
At 6 months 270 of the 368 who had qualified for analysis remained dry giving a continued success rate of 73%. The 31 not qualifying were not used for the success rate as they had not achieved 6 months since initial success. Similarly for 24 months the complete success rate was 64%, those not achieving 24 months not included as their outcomes were not known at 24 months.
Delaney et al. in their revised chart point to a 24-month success rate of 34% being similar to natural remission. Their flow chart compares the total remaining dry at 24 months, with those reaching 24-month follow-up as well as those not that had not reached this follow-up period, some just over 6 months from achieving dryness. To the casual observer this could lead to some confusion about alarm management in enuresis. We all seem to agree that alarm management is ‘an effective tool in the management of nocturnal enuresis’ and the initial success rate compares favourably with the Cochrane review (relative risk of failure 0.24 compared with Cochrane review of 0.38), and have a similar success at 6-month follow-up. However, at 24 months only spontaneous remission rate achievable. Does this mean alarm success is only short lived? With our large group of children achieving initial success (399), this would be worthy of resubmitting the paper as a study of profound alarm failure!
The study gives very useful and practical information for managing enuresis and answers many of the questions parents ask.
‘What is the likelihood that my child, if we proceed with management, will achieve dryness’– 79.0%
‘Will my child stay dry if he achieves initial dryness?’– 73% will remain dry at 6 months and 64% will have remained dry by the end of 24 months.
‘How long will treatment take’– table 1 in the paper gives a useful indication of times to success and can indicate to parents that the ‘main body of children achieving dryness’ is within the 4- to 11-week period.
Table 2 in the paper gives the cumulative percent achieving dryness and is useful to indicate to parents what percentage can still achieve dryness at certain stages of their program. This is particularly useful for those who are taking a longer time.
Such outcome data is helpful both in community-based paediatrics but also in major metropolitan paediatric hospitals.