Laxative Use in Patients With Advanced Chronic Kidney Disease Transitioning to Dialysis

Keiichi Sumida; Ankur A. Dashputre; Praveen K. Potukuchi; Fridtjof Thomas; Yoshitsugu Obi; Miklos Z. Molnar; Justin D. Gatwood; Elani Streja; Kamyar Kalantar-Zadeh; Csaba P. Kovesdy

Disclosures

Nephrol Dial Transplant. 2021;36(11):2018-2026. 

In This Article

Results

Laxative use During the Transition Period

Within each 6-month period over the entire 72-month transition period, the proportion of patients with at least one laxative prescription ranged from 17.5% to 37.1% (Supplementary data, Table S3). As depicted in Figure 1, the use of laxatives gradually increased as patients progressed to ESRD, with a marked increase seen in the 6 months immediately prior to ESRD transition. Laxative use peaked in the first 6 months following dialysis initiation and remained fairly stable at ~30% throughout the post-ESRD period (Figure 1). The proportion of patients who had continuous laxative prescriptions throughout the entire transition period was 2.8%.

Figure 1.

Proportion of laxative use within each 6-month period over 36 months pre- and post-ESRD transition.

Among patients with at least one laxative prescription, the majority (≥55%) was prescribed a single type of laxative throughout the transition period, with stool softeners being the most commonly prescribed (25.8–31.5%), followed by hyperosmotics (16.9–20.8%), stimulants (8.8–11.7%), bulk formers (1.3–4.3%) and chloride channel activator (0–0.02%) (Figure 2 and Supplementary data, Table S4). There was a decreasing trend in the overall proportion of patients who used a single type of laxative over time, with a marked temporary drop seen in the 6 months immediately before and after the ESRD transition. A corresponding increase in the overall proportion of combined use of laxatives was observed. Among different laxative types, stool softeners, hyperosmotics and stimulants were commonly used in combination with each other (Figure 2 and Supplementary data, Table S4). There was a graded relationship between the number of different types of laxatives and the number of prescribed drugs (Supplementary data, Table S5).

Figure 2.

Proportion of laxative types used alone or in combination among patients with at least one laxative prescription within each 6-month period over 36 months pre- and post-ESRD transition. Solid (red) and dotted (blue) lines represent single and combined use of laxatives, respectively.

Factors Associated With Laxative use

In a total of 46 632 patients included in this analysis, baseline characteristics overall and in those categorized by laxative use status are shown in Table 1. The overall mean (SD) age was 72.5 (11.3) years; 95.2% of patients were male; 22.7% were African American; and 72.9% were diabetic. The mean baseline eGFR was 32.5 mL/min/1.73 m2. Compared with nonlaxative users, laxative users were younger, more likely to be African American, a current smoker and service connected, and less likely to be married. They had a higher prevalence of diabetes as a primary cause of ESRD and comorbidities except cerebrovascular disease, connective tissue disease, peptic ulcer disease, malignancy and atrial fibrillation, and also had longer cumulative length of hospitalization during the 2-year baseline period. The use of medications except calcium channel blockers was more common among laxative users.

Figure 3 shows the factors independently associated with pre-ESRD laxative use in descending order of the magnitude of the odds ratio (OR). In the multivariable-adjusted model, the use of certain medications such as anticoagulants [OR 4.24, 95% confidence interval (CI) 3.88–4.63], oral iron supplements (3.42, 95% CI 3.17–3.69), non-opioid analgesics (2.51, 95% CI 2.34–2.69), antihistamines (2.47, 95% CI 2.15–2.84) and opioid analgesics (2.11, 95% CI 1.98–2.23) were among the strongest factors positively associated with pre-ESRD laxative use. African American (versus white) race and the presence of anemia (OR 1.35, 95% CI 1.24–1.47), depression (1.32, 95% CI 1.16–1.49) and liver disease (1.11, 95% CI 1.03–1.20) were also associated with pre-ESRD laxative use. Meanwhile, married (versus unmarried) status (OR 0.69, 95% CI 0.65–0.73) and certain comorbidities such as HIV/AIDS (0.56, 95% CI 0.42–0.76), connective tissue disease (0.69, 95% CI 0.62–0.77) and hyperlipidemia (0.74, 95% CI 0.68–0.82) were negatively associated with pre-ESRD laxative use (Figure 3).

Figure 3.

Factors independently associated with pre-ESRD laxative use. Pre-ESRD laxative use was defined as at least two laxative prescriptions 30-days apart during the 1-year pre-ESRD period.

Factors significantly associated with pre-ESRD laxative use were fairly similar after additional adjustment for BMI, systolic blood pressure, last eGFR and eGFR slope in a sensitivity analysis. Of note, eGFR slopes less than −10 and ≥0 (versus −5 to <0) mL/min/1.73 m2/year were both associated with pre-ESRD laxative use (ORs 1.56, 95% CI 1.35–1.81 and 1.41, 95% CI 1.28–1.54, respectively) (Supplementary data, Figure S2). The odds of pre-ESRD laxative use associated with all examined variables are summarized in Supplementary data, Table S6.

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