[Factors associated with colon cleansing measured with the Boston scale in routine clinical practice]

The Boston scale is useful to standardize colon cleansing at colonoscopy. The aim of this study was to analyze the degree of preparation before colonoscopy and the factors associated with cleansing in routine clinical practice.

We included colonoscopies performed from January to June 2013. Exclusion criteria were age <15 years, a history of colon surgery, inflammatory bowel disease, and active gastrointestinal bleeding. The standard preparation was CitraFleet. The parameters related to the degree of bowel cleansing (using the Boston scale) were age, sex, indication, colonoscopy shift (morning or afternoon), patient origin (outpatient or hospitalized), and colonoscopy findings.

We analyzed 947 colonoscopies, with exclusion of 297. A total of 5.8% (38/650) of the colonoscopies were incomplete, 50% due to lack of preparation. The mean age of the patients was 61.27 years (SD: 16.1), and 51.8% were women. The distribution of the Boston scale was 0-3 in 6.3%, 4-5 in 12.6%, 6-7 in 30.6%, and 8-9 in 50.4%, with a mean 7.04 (SD: 2.03). On multivariate analysis, the factors statistically associated with better preparation were younger age, afternoon colonoscopy and the outpatient setting. The percentage of polyps in patients with a Boston scale score ≤5 was 10% compared with 27.8% in patients with a score > 5 (P=.014).

In clinical practice, 80% of patients had an acceptable level of preparation. Older patients, those undergoing colonoscopy in the morning and hospitalized patients would be candidates for measures to improve the degree of colonic preparation.