scholarly journals The use of segmented regression in analysing interrupted time series studies: an example in pre-hospital ambulance care

2014 ◽  
Vol 9 (1) ◽  
Author(s):  
Monica Taljaard ◽  
Joanne E McKenzie ◽  
Craig R Ramsay ◽  
Jeremy M Grimshaw
Keyword(s):  
Time Series ◽  
Interrupted Time Series ◽  
Segmented Regression ◽  
Time Series Studies

The Impact of a National Antimicrobial Stewardship Program on Antibiotic Prescribing in Primary Care: An Interrupted Time Series Analysis

2018 ◽  
Vol 69 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Violeta Balinskaite ◽  
Alan P Johnson ◽  
Alison Holmes ◽  
Paul Aylin
Keyword(s):  
Primary Care ◽  
Time Series ◽  
Broad Spectrum ◽  
Interrupted Time Series ◽  
Series Data ◽  
Antibiotic Prescribing ◽  
Segmented Regression ◽  
Broad Spectrum Antibiotic ◽  
Stewardship Program ◽  
The Impact

Abstract Background The Quality Premium was introduced in 2015 to financially reward local commissioners of healthcare in England for targeted reductions in antibiotic prescribing in primary care. Methods We used a national antibiotic prescribing dataset from April 2013 until February 2017 to examine the number of antibiotic items prescribed, the total number of antibiotic items prescribed per STAR-PU (specific therapeutic group age/sex-related prescribing units), the number of broad-spectrum antibiotic items prescribed, and broad-spectrum antibiotic items prescribed, expressed as a percentage of the total number of antibiotic items. To evaluate the impact of the Quality Premium on antibiotic prescribing, we used a segmented regression analysis of interrupted time series data. Results During the study period, over 140 million antibiotic items were prescribed in primary care. Following the introduction of the Quality Premium, antibiotic items prescribed decreased by 8.2%, representing 5933563 fewer antibiotic items prescribed during the 23 post-intervention months, as compared with the expected numbers based on the trend in the pre-intervention period. After adjusting for the age and sex distribution in the population, the segmented regression model also showed a significant relative decrease in antibiotic items prescribed per STAR-PU. A similar effect was found for broad-spectrum antibiotics (comprising 10.1% of total antibiotic prescribing), with an 18.9% reduction in prescribing. Conclusions This study shows that the introduction of financial incentives for local commissioners of healthcare to improve the quality of prescribing was associated with a significant reduction in both total and broad-spectrum antibiotic prescribing in primary care in England.

scholarly journals On ignoring instead of chasing after coagulation factor VII during warfarin management; an interrupted time series study

Blood ◽  
2021 ◽  
Author(s):  
Alma R. Oskarsdottir ◽  
Brynja R. Gudmundsdottir ◽  
Hulda M. Jensdottir ◽  
Bjorn Flygenring ◽  
Ragnar Palsson ◽  
...  
Keyword(s):  
Time Series ◽  
Coagulation Factor ◽  
Maintenance Phase ◽  
Interrupted Time Series ◽  
Factor Vii ◽  
Segmented Regression ◽  
Post Intervention ◽  
Coagulation Factor Vii ◽  
Monitoring Test ◽  
Time In Range

During warfarin management, prothrombin time (PT) based PT-INR variability is partly due to clinically inconsequential fluctuations of factor (F) VII. The new Fiix-PT and Fiix-normalized ratio (Fiix-NR), unlike PT-INR, is only affected by reduced FII and FX. Starting July 1st 2016 we replaced PT-INR monitoring of warfarin with Fiix-NR in our patients. Using interrupted time series methods, we retrospectively assessed if this affected thromboembolism (TE) and major bleeding (MB) incidence during 12 months prior to and 18 months after the replacement, months 13-18 being predefined as transitional months. The dynamic cohort comprised all our service´s 2,667 maintenance phase warfarin patients managed at any time during the 30 months. Using two-segmented regression, a breakpoint in total TE monthly incidence became evident six months after laboratory monitoring test replacement, followed by 56% reduction in TE incidence (from 2.82% to 1.23% per patient year, P=0.019 by ANOVA). Three-segmented regression found no significant TE incidence trend (slope +0.03) prior to test replacement but during months 13-18 and 19-30 the TE incidence gradually decreased (slope -0.12; R2=0.20;P=0.007). Based on segmented regressions, MB incidence (2.79% ppy) did not differ pre- or post-intervention. Incidence comparison during the 12 month Fiix- and PT-periods confirmed a statistically significant 55-62% reduction in TE. Fiix-monitoring reduced testing, dose adjustments and normalized ratio variability, and prolonged testing intervals and time in range. We conclude that ignoring FVII during Fiix-NR monitoring in real world practice stabilizes the anticoagulant effect of warfarin and associates with major reduction in thromboembolism without increasing bleeding.

scholarly journals Evaluation of a complex intervention to improve primary care prescribing: a phase IV segmented regression interrupted time series analysis

2017 ◽  
Vol 67 (658) ◽  
pp. e352-e360 ◽  
Author(s):  
Sean MacBride-Stewart ◽  
Charis Marwick ◽  
Neil Houston ◽  
Iain Watt ◽  
Andrea Patton ◽  
...  
Keyword(s):  
Primary Care ◽  
Time Series ◽  
High Risk ◽  
Older People ◽  
Secondary Analysis ◽  
Interrupted Time Series ◽  
Segmented Regression ◽  
Intervention Period ◽  
Interrupted Time Series Analysis ◽  
Primary Analysis

BackgroundIt is uncertain whether improvements in primary care high-risk prescribing seen in research trials can be realised in the real-world setting.AimTo evaluate the impact of a 1-year system-wide phase IV prescribing safety improvement initiative, which included education, feedback, support to identify patients to review, and small financial incentives.Design and settingAn interrupted time series analysis of targeted high-risk prescribing in all 56 general practices in NHS Forth Valley, Scotland, was performed. In 2013–2014, this focused on high-risk non-steroidal anti-inflammatory drugs (NSAIDs) in older people and NSAIDs with oral anticoagulants; in 2014–2015, it focused on antipsychotics in older people.MethodThe primary analysis used segmented regression analysis to estimate impact at the end of the intervention, and 12 months later. The secondary analysis used difference-in-difference methods to compare Forth Valley changes with those in NHS Greater Glasgow and Clyde (GGC).ResultsIn the primary analysis, downward trends for all three NSAID measures that were existent before the intervention statistically significantly steepened following implementation of the intervention. At the end of the intervention period, 1221 fewer patients than expected were prescribed a high-risk NSAID. In contrast, antipsychotic prescribing in older people increased slowly over time, with no intervention-associated change. In the secondary analysis, reductions at the end of the intervention period in all three NSAID measures were statistically significantly greater in NHS Forth Valley than in NHS GGC, but only significantly greater for two of these measures 12 months after the intervention finished.ConclusionThere were substantial and sustained reductions in the high-risk prescribing of NSAIDs, although with some waning of effect 12 months after the intervention ceased. The same intervention had no effect on antipsychotic prescribing in older people.

Sign in / Sign up

Export Citation Format

Share Document