Exploring treatment burden of Oral Nutritional Supplements (ONS) and impact on antibiotics using a data linkage approach
Authors: Fisher R , Smith A , Rosembert D 
Published: November 2023

Abstract

Introduction
Treatment burden associated with thickeners is significant1. Understanding of potential treatment burden associated with ONS is lacking, however wastage due to ONS partial or full nonconsumption, and stock piling are recognised2. Wastage is evidence of over prescribing. Improving fluid intake by increasing variety is evidence based3 - ONS reduces opportunity.
Whether thickener or ONS is prescribed, patients can withdraw consent by not drinking (verbally/silently). We investigated a potential correlation between ONS and low intake dehydration, and if detectable using a proxy measure: antibiotic prescribing for urinary tract infection (UTI). We explored using ePACT2 data to investigate co-prescribing of interventions that inter-relate, a type of data linkage study. Improved fluid intake can decrease laxative use, but did not reduce antibiotic use3. We hypothesized that with a large data set, it may be possible to detect associations of treatment burden and antibiotic use.

Aim
To explore the relationship between prescribing of ONS with antibiotics for UTIs in older adults in Primary Care (England).

Methods
We investigated co-prescribing of antibiotics prescribed for UTI (nitrofurantoin, trimethoprim) and ONS in older adults (&gt; 65 years) in Primary Care. Data was obtained from the NHS Business Services Authority Data Services Support as bespoke analysis of prescribing ePACT2 data linked by NHS number. Retrospective analysis was performed on anonymised data for 3 years (January 2019 to December 2022). Ethical approval was not required. Data unattributable to a specific region was excluded.

Results
Initial analysis suggested that prescribing of UTI antibiotics was 3 times more common in older adults prescribed ONS compared with controls (an average 2.86% of the patients on GP list were prescribed an antibiotic for a UTI, increasing to 8.59% for those co-prescribed ONS). This correlation appeared consistent, however, due to high volume and level of detail of UTI antibiotic prescribing, this interpretation is incorrect. On further analysis, the population rate of UTI antibiotic and ONS was plotted to show trend over time, demonstrating no correlation. Prescription of UTI antibiotic over time is consistent, reflecting that acute lower UTI is not very reducible, and antibiotic prophylaxis use is common and repeated monthly.
Additionally, from this data set you cannot ascertain if frequency of antibiotic prescription(s) pre-dates initiation of ONS. We did not investigate confounding factors such as co-prescribing of catheter use, gender, frailty and advancing age. Our oldest patients with decreased thirst, reduced appetite cues and ability to eat and drink will also be those most likely to get an UTI.

Discussion/Conclusion
Future data linkage work in this area should include a wider range of data e.g. detailed demographics, medical and prescribing history over time and all adverse events from low intake dehydration. Exploration of the impact of ONS and thickener prescription on patient experience, perceived treatment burden and the impact on fluid intake would be useful. Audit of shared decision making at initiation and review would also be beneficial in obtaining baseline data on consent at start and throughout duration of prescription.

References
1. Steele SJ, Ennis SL, Dobler CC. Treatment burden associated with the intake of thickened fluids. Breathe 2021; 17: 210003.
2. Collins, C.; Tucker, C.; Walton, C.; Podbur, S.; Barrett, S. Pharmacy Technician Review of Oral Nutritional Supplements (ONS) within Care Homes. Pharmacy 2019, 7, 28. https://doi.org/10.3390/pharmacy7010028
3. Wilson J, Bak A, Tingle A, Greene C, Tsiami A, Canning D, Myron R, Loveday H. Improving hydration of care home residents by increasing choice and opportunity to drink: A quality improvement study. Clin Nutr. 2019 Aug;38(4):1820-1827. doi: 10.1016/j.clnu.2018.07.020. Epub 2018 Aug 4. PMID: 30150005.