NO CHANGE IN PRIMARY HEALTH CARE COST AMONG PEOPLE WITH IBS IN THE TWO YEARS FOLLOWING REFERRAL TO A GASTROENTEROLOGIST: A UK DATABASE COHORT STUDY

Purpose:    Irritable bowel syndrome (IBS) is a functional gastrointestinal condition affecting 11% of people internationally.  No definitive diagnostic investigation exists and international guidelines recommend clinical diagnosis and management within primary care.  Only 4% of patients diagnosed with IBS in primary care are later diagnosed with a serious organic gastrointestinal diagnosis.  Despite this, many patients are referred to gastroenterology, incurring substantial healthcare costs.  This study seeks to assess if visiting a gastroenterologist reduces the amount and cost of primary care utilization for IBS patients.

Methods:    We identified within the UK Clinical Practice Research Dataset IBS patients who had their first gastroenterology outpatient appointment identified in UK Hospital Episode Statistics in 2008 and 2009. Anyone diagnosed with organic gastrointestinal disease was excluded.  Consultation rates and rate ratios were estimated. We applied costs according to the 2012 UK NHS tariff. 

Results:    There were 3010 people with IBS referred to gastroenterologists for the first time in 2008 and 2009. Their mean age was 48 years and 71% were women.  Median time from IBS diagnosis to seeing a gastroenterologist was 30 weeks.  The table shows rates and costs of primary care utilization before and after attending gastroenterology.

Time from year of first gastroenterology appointment	Primary care visits per person year
	Crude rate (95% CI)	Median number (IQR)	Median cost (IQR)
Two years before	5.4 [5.3, 5.5]	5 [2, 8]	£154 [£72, £272]
One year before	5.9 [5.8, 6.0]	5 [3, 9]	£180 [£95, £288]
Index year	7.9 [7.8, 8.0]	7 [5, 11]	£239 [£144, £364]
One year after	6.3 [6.2, 6.4]	6 [3, 9]	£180 [£108, £311]
Two years after	6.6 [6.5, 6.7]	5 [2, 8]	£154 [£72, £275]

   The rate ratio, adjusted for age, sex and socioeconomic status, comparing the two years before with the two years after was 1.12 (95% CI 1.10 to 1.14).  Costs increased substantially during year of referral, then returned near to baseline.

Conclusions:   Patients with IBS referred to gastroenterology had significantly increased primary care utilization and cost during the year in which a patient was referred.  There was a small increase in frequency of attendance at primary care in the two years following their out-patient appointment compared to the two years before and no increase or decrease to the healthcare costs in primary care.