Significant psychological morbidity occurs in irritable bowel syndrome: a case-control study using a pharmacy reimbursement database.
BACKGROUND
Psychological problems are associated with IBS but the strength of this association is unclear.


OBJECTIVE
To assess co-prescribing of antispasmodic and CNS-acting drugs through a nested case-control study.


METHODS
A national dispensing database identified patients who were first dispensed antispasmodic medicines for a continuous 3-month period or more during 2006, using 2005 as a run-in period. Each patient was matched with four control patients and excluded if they received drugs indicated for IBD.


RESULTS
Four hundred and seven patients commenced antispasmodic drugs during 2006. These patients were matched with 1628 controls. In 2005, patients subsequently prescribed antispasmodics were 2-3 times more likely to receive CNS-acting drugs than controls. In the year following commencement of IBS therapy, patients were 2-4 times more likely than controls to be prescribed CNS-acting drugs including antidepressants (35.4% vs. 9.3%), anxiolytics (27.8% vs. 8.8%), antipsychotics (9.8% vs. 3.3%) and hypno-sedatives (32.7% vs. 11.3%; P < 0.0001). The adjusted OR (95% CI) for antidepressant, anxiolytic, hypnosedative and antipsychotic prescribing in IBS patients were 3.81 (2.79-5.20), 2.84 (2.12-3.81), 2.62 (1.91-3.60) and 2.58 (1.80-3.66), respectively.


CONCLUSIONS
Patients prescribed ongoing therapy for presumed IBS are 2-4 times more likely to be prescribed CNS-acting drugs than controls, providing evidence of psychological comorbidity in IBS.
Canavan
J B
JB
Gastroenterology Unit, The John Radcliffe Hospital, Oxford, UK. jim@drcanavan.com
Bennett
K
K
Feely
J
J
O'Moráin
C A
CA
O'Connor
H J
HJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000150:complications* / Q000188:drug therapy; D016022:Case-Control Studies; D016208:Databases, Factual; D003866:Depressive Disorder / Q000150:complications* / Q000188:drug therapy; D004347:Drug Interactions; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010276:Parasympatholytics / Q000627:therapeutic use*; D017891:Pharmacoepidemiology
D000928:Antidepressive Agents; D010276:Parasympatholytics