Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Obstetric patient safety indicator may be invalid
- Lucy C Chappell, Con J Kelleher (24 October 2008)
-
Obstetric patient safety indicator may be invalid: author response
- Veena S Raleigh, Jeremy Cooper, Stephen A Bremner, and Sarah Scobie (25 November 2008)
|
|
|||
|
Lucy C Chappell, Senior Lecturer in Maternal and Fetal Medicine Guy's and St Thomas' NHS Foundation Trust, Con J Kelleher
Send response to journal:
|
Raleigh and colleagues (1) report obstetric patient safety indicators relating to third/ fourth degree trauma in three different scenarios: associated with instrument assisted vaginal deliveries, without such assistance and with concurrent Caesarean delivery. It is difficult to comprehend how the last of these three occurs at the frequency reported in their study, which raises concerns over the validity of the other data. They suggest the scenario of ‘a trial of labour with instrumental assistance, which subsequently results in a caesarean delivery’. In order to sustain third/ fourth degree trauma, this would entail delivery of the baby’s head, at least, with significant perineal damage, followed by Caesarean delivery. The extremely rare scenario in which this might occur would be the most severe type of shoulder dystocia, in which after all other interventions have failed, the Zavanelli manoeuvre is undertaken to replace the baby’s head prior to Caesarean section (2). The other potential scenario in which concurrent third/ fourth degree trauma and Caesarean delivery might occur is during birth of twins, in which the first is born vaginally with extensive perineal damage and the second by Caesarean. However, as twin pregnancies are delivered at an earlier median gestational age (37 weeks’ gestation) (3) and at a lower median birthweight compared to singletons, significant perineal trauma is much less likely. If the rate of this indicator is 2.86 per 1000 deliveries, as they report, we would expect to see approximately 17 events per year in our maternity unit of over 6000 deliveries per annum. Our risk management team (led by CK) reviews every case of third/ fourth degree trauma and in the last five years have never discovered a case of simultaneous third/ fourth degree trauma with concurrent Caesarean delivery. It is unlikely that this finding is unique to our unit. The authors state that ‘lack of random variation indicates some consistency in coding.’ If the data are consistently coded wrongly, then the error is merely perpetuated. The comment that ‘Measures based on administrative data are reported to be generally high in specificity (that is, low rate of false positives)’ does not appear to be accurate with regard to this indicator. We would suggest that their data for concurrent third/ fourth degree trauma with Caesarean delivery have an extremely high rate of false positives, which has not been identified at any stage as incongruous. Coding and collection of administrative data are essential components of any healthcare system. If clinical input and common sense are lacking, then overall validity is called into question and the data are all the weaker for it. 1. Raleigh VS, Cooper J, Bremner SA, Scobie S. BMJ 2008;337:a1702. doi:10.1136/bmj.a1702 2. Sandberg EC. The Zavanelli maneuver: 12 years of recorded experience. Obstet Gynecol. 1999;93:312-7. 3. Kiely JL. What is the population-based risk of preterm birth among twins and other multiples? Clin Obstet Gynecol. 1998;41:3-11. Competing interests: None declared |
|||
|
|
|||
|
Veena S Raleigh, Fellow in Information Policy Healthcare Commission, EC1Y 8TG, Jeremy Cooper, Stephen A Bremner, and Sarah Scobie
Send response to journal:
|
Further to the comments by Chappell and Kelleher (1) on our paper on the AHRQ patient safety indicators(2), we’d like to state that we welcome feedback on the validity of the indicators. We would also like to clarify that the denominator for the indicator for obstetric trauma in the case of caesarean deliveries is the number of births delivered by caesarean section, and not all deliveries. So a maternity unit with 6000 deliveries a year, of which (as an example) 20% were caesarean, would have about 3 cases a year, not 17. It is also worth noting that England’s rate for this indicator is generally lower than rates for other countries participating in the OECD pilot data collection. We agree that the individual cases contributing to the indicators and the coding of events merit clinical investigation, and we concluded in our paper that "our results suggest that the indicators have potential for monitoring patient safety events in the UK but require more in-depth validation of individual cases and better coding of events." VS Raleigh, J Cooper, SA Bremner, S Scobie 25 November 2008 1. Chappell LC, Kelleher CJ. Obstetric patient safety indicator may be invalid. http://www.bmj.com/cgi/eletters/337/oct17_1/a1702#203668 2. Raleigh VS, Cooper J, Bremner SA, Scobie S. Patient safety indicators for England from hospital administrative data: case-control analysis and comparison with US data. BMJ 2008;337:a1702. Competing interests: None declared |
|||