We performed a descriptive analysis of the study patient sample (N = 48,336 cases) and compared the patients with and without a UTI-related hospitalization or ED visits (Table 2, Additional file 1). A total of 1,689 patients (3.5%) had UTI related hospitalization or ED visit. Patients were 78 years old on average, mostly female (63.2%) and 58.5% were white. Most patients (54.3%) had a history of short-stay acute hospital visits within 14 days of HHC admission and about 23.6% patients reported urinary incontinence existed prior to the inpatient stay or change in medical or treatment regimen. Hypertension, diabetes, arthritis were the top three diagnoses, and most patients were assessed on admission as being likely to return to a stable condition (73.8%). compared with patients without UTI-related hospitalization or ED visits, those developed the UTI events were significantly older (80 vs 78 years) and more likely to be female (66.5% vs 63.1%). No statistically significant differences were found between patients with and without UTI-related hospitalization or ED visits among different races. Patients with a UTI-related hospitalization or ED visits were more likely to have had a skilled nursing facility or inpatient rehabilitation hospital or long-term care stay 14 days prior to the HHC admission as well as urine incontinence, an indwelling catheter, and impaired decision-making than those without a UTI-related hospitalization or ED visits. Diabetes, dementia, heart failure, cardiac dysrhythmias, neurological disorder, skin ulcer, and stroke were significantly more frequent among patients with UTI-related hospitalization or ED visits, whereas arthritis was less common in these groups compared to patients without a UTI-related hospitalization or ED visits.
After bivariate analysis review, 137 variables (out of over 500) were selected to be entered into stepwise logistic regression. A full list of variables is included in Table S. (Table S., Additional file 2). The variables were from various domains ranging from demographics to previous history, current medical conditions, physical function, care management, medication regimen, and admission vital signs.
Identified risk factors for UTI-related hospitalization or ED visits
Risk factors identified by the stepwise logistic regression model are displayed in Table 3 (Table 3., Additional file 1). Demographic factors associated with UTI related hospitalization or ED visits included being female (OR = 1.31; 95% CI: 1.15–1.5), having history of falls (OR = 1.24; 95% CI: 1.08– 1.44), and multiple previous hospitalizations (OR = 1.16; 95% CI: 1.12–1.32).
Patients’ elimination status was closely associated with a UTI-related hospitalization or ED visits. Patients who had a urinary catheter present during an HHC admission had 4.7 times higher odds of developing UTI related hospitalization or ED visit compared to those without these events (odds ratio [OR] = 5.7; 95% confidence interval [CI]: 4.54–7.14). Patients who were treated for a UTI in the 14 days prior to HHC admission had 84% higher odds compared to those who were not (OR = 1.84; 95% CI: 1.56– 2.17). Being urine or bowel incontinent at HHC admission were both associated with a UTI-related hospitalization or ED visits. Patients who were experiencing urine incontinence during day and night had increased odds by 28% (OR = 1.28; 95% CI: 1.06– 1.53). Bowel ostomy and incontinence also increased the odds of patients’ UTI-related hospitalization or ED visits by 77% (OR = 1.77; 95% CI: 1.19– 2.64) and 72% (OR = 1.72; 95% CI: 1.19– 2.49), respectively.
Multiple medications were associated with HHC patients’ UTI-related hospitalization or ED visits. One of the most notable findings involved general antibacterials and antiseptics. These medications were associated with a 175% (OR = 2.75; 95% CI: 1.02–7.38) higher odds of a UTI-related hospitalization or ED visits. Other medications included in the final stepwise model were all associated with increased odds of UTI-related hospitalization or ED visits. Among them, anti-diarrheals and sulfonamides increased patients’ odds of UTI-related hospitalization or ED visits by 60% (OR = 1.6; 95% CI: 1.02–2.51) and 56% (OR = 1.56; 95% CI: 0.91–30.09), respectively.
Patients with difficulty performing IADL showed higher odds of a UTI-related hospitalization or ED visits. Those who were unable to prepare light meals or any meals had a 52% (OR = 1.52; 95% CI: 1.03–2.23) and 78% (OR = 1.78; 95% CI: 1.21–2.64) higher odds compared to those who were able, respectively. Interestingly, compared to those without a surgical wound, patients who had a problematic observable surgical wound had lower odds, at about 37% (OR = 0.63; 95% CI: 0.52–0.75).
Caregiver availability was found to be associated with UTI-related hospitalization or ED visits under the care management category. Patients identified as unlikely to have non-agency caregivers or unclear or no caregiver available to provide assistance had 79% higher (OR = 1.79; 95% CI: 1.2–2.68) odds of UTI-related hospitalization or ED visits compared to those who did not need assistance.
In addition, compared to those with normal or low body temperature, the odds of having a UTI related hospitalization or ED visit were 2.68 higher (OR = 2.68; 95% CI: 1.46–4.93) among patients with high body temperature.
Among patients’ diagnoses, having a skin ulcer increased the odds of a UTI-related hospitalization or ED visits by 41% (OR = 1.41; 95% CI: 1.2–1.66). Having diabetes or cardiac dysrhythmias increased odds of UTI-related hospitalization or ED visits by 24% (OR = 1.24; 95% CI: 1.1–1.41) and 19% (OR = 1.19; 95% CI: 1.01–1.41), respectively, whereas having arthritis or cerebral degeneration decreased odds of UTI-related hospitalization or ED visits by 19% (OR = 0.81; 95% CI: 0.68–0.97) and 29% (OR = 0.71; 95% CI: 0.52–0.97), respectively. Previous history of no discharge from an in-patient facility was associated with a 30% (OR = 0.7; 95% CI: 0.6–0.82) decrease in odds of UTI-related hospitalization or ED visits.
A predictive model for UTI related hospitalization or ED visit was developed based on the 27 risk factors that were identified by a multivariable logistic regression model. The performance of the prediction model was evaluated by Area under the Receiver Operating Curve (AUC). The predictive model showed good predictive performance with the AUC statistic of 0.75 [11] .