Table 2.
Estimated effect of introduction of NHS Direct on changes in service use
| Service | Durbin-Watson statistic (significance*) | Estimated trend in use per month (%)
|
Change in trend (95% CI) | Test statistic† | |
|---|---|---|---|---|---|
| Before introduction | After introduction | ||||
| Ambulance services | |||||
| Milton Keynes | 1.9 (NS) | 0.7 | −0.2 | −0.9 (−2.0 to 0.2) | t=−1.61, P=0.14 |
| Preston and Chorley | 1.1 (S) | 1.0 | 0.9 | −0.1 (−1.7 to 1.6) | t=−0.11, P>0.5 |
| Northumbria | 1.6 (NS) | 0.8 | 0.6 | −0.2 (−1.2 to 0.8) | t=−0.45, P>0.5 |
| Accident and emergency departments | |||||
| Milton Keynes | 1.1 (S) | 0.2 | 0.7 | 0.5 (−0.2 to 1.3) | t=1.42, P=0.16 |
| Preston and Chorley | 2.6 (I) | 0.0 | −0.1 | −0.1 (−0.8 to 0.5) | t=−0.34, P>0.5 |
| Northumbria | 2.3 (NS) | −0.1 | 0.0 | 0.2 (−0.5 to 0.8) | t=0.52, P>0.5 |
| General practitioner cooperatives | |||||
| Milton Keynes | 2.4 (NS) | 1.9 | −0.9 | −2.8 (−6.5 to 1.1) | t=−1.42, P=0.16 |
| Preston and Chorley | 1.2 (I) | 2.2 | −0.2 | −2.3 (−5.0 to 0.4) | t=−1.71, P=0.09 |
| Northumbria | 1.6 (NS) | 2.1 | −1.3 | −3.4 (−5.7 to −1.0) | t=−2.82, P=0.02 |
*
S=significant at P=0.05 but not at p=0.025; NS=not significant; I=inconclusive.
†
All t statistics have 10 degrees of freedom except for ambulance services in Milton Keynes, which had 9 because of one missing data point.