Peter Baghurst Public Health Research Unit Women’s and Children’s Hospital

Limitations on cross-correlations of single indicators: The case for a WHA clinical outcomes (unit-record) database. Peter Baghurst Public Health Research Unit Women’s and Children’s Hospital Women’s and Children’s Healthcare Network North Adelaide, South Australia

Epidurals and PPH within one hospital 13,778 vaginal births with PPH volumes at Women’s and Children’s Hospital No significant risk associated with epidural use (Odds ratio=1.05, p = 0.70) – and after adjusting for known risk factors, the Odds Ratio fell to 0.80,(p = 0.14). Highly significant increased risk,Odds ratio 1.38, (p < 0.001) – but after adjustment the Odds Ratio fell to 0.91, (p = 0.10).

% third and fourth degree tears in SA By parity and epidural use Epidural use is associated with increased perineal trauma By instrument assistance, parity and epidural use Epidural use is associated with less perineal trauma in all groups!! (But we needed data on individual women to construct this table)

Is stratification (selected primiparas) enough? • Recall a selected primip is a woman giving birth • For the first time • At term (with vertex presentation) • Aged 20-34 years • We examine outcomes in this group under the assumption that these women are more homogeneous with res[pect to their risk of particular outcomes • But…. If we look at, say, severe perineal tears in selected primips, the probability of a tear may vary from less than 1% in a Caucasian woman giving birth spontaneously to a 2200g baby; to 50% in a Chinese woman having a 4200g baby and requiring assistance with forceps • Also……selected primips comprise only 25% of the obstetric population. Shouldn’t we be paying more attention to the others?

The message… • Cross-correlation of single clinical indicators is interesting – but interpretation is severely restricted – because most clinical outcomes are determined by multiple ‘risk’ factors. • In order to compare hospital-outcomes fairly, we need to adjust for major risk factors – and this requires access to data on individual women (some times referred to as “unit-record” data).

How might it work? • Member hospitals would send de-identified data files (e.g., Excel spreadsheets, in which each row contained data-items on every individual in their care over the past twelve months) - to WHA. • If neonatal outcomes are held in separate file – two files would have to be uploaded • A data analyst at WHA, in consultation with each member hospital) would pre-process these files to extract and compute common items required for the construction of clinical indicators (i.e., there would be NO demand for the uploaded data to be in a common format!) • Clinical indicators would be generated for all members at WHA. (No more having to do it yourself!)

Advantages • Current WHA indicators could be automatically calculated from such a database (no more pestering from me!) • The database would become an extremely useful research tool for studies approved by WHA members • This could well attract research funding

Potential problems • AIHW is currently considering establishing a national database. The list of data items currently proposed is huge – and it might take many years – and a lot of good will - for all hospitals to collect data in a standardised format. • Overlap with local jurisdictional data collections?

Peter Baghurst Public Health Research Unit Women’s and Children’s Hospital