Background:

The WATCH-DM integer-based risk score (WATCH-DM(i)) was originally developed and validated to predict heart failure (HF) hospitalization risk in patients with type 2 diabetes mellitus (T2DM). However, its potential association with all-cause mortality in patients without HF remains unclear.

Objectives:

This study aimed to evaluate the prognostic utility of the WATCH-DM(i) score for all-cause mortality in a real-world outpatient cohort of T2DM patients without known HF.

Design:

This was a retrospective observational cohort study with national mortality registry linkage performed at a single center.

Methods:

We analyzed data from 449 adults with T2DM enrolled in a hospital-based cohort between 2016 and 2022. The WATCH-DM(i) score was calculated according to the original published integer-based model reported by Segar et al., using clinical and laboratory parameters. Patients were stratified into four risk groups based on their score. All-cause mortality data were obtained via national linkage. Cox regression models, Kaplan–Meier survival analysis, landmark analysis, and time-dependent receiver operating characteristic curves were used to assess mortality risk.

Results:

Over a median follow-up of 61 months, 39 patients (8.7%) died. Each 1-point increase in the WATCH-DM(i) score was associated with a 29% higher risk of all-cause mortality (HR: 1.287, 95% CI: 1.151–1.439, p < 0.001). Higher risk groups showed progressively greater mortality, especially after 24 months. The score demonstrated good discrimination for 5-year mortality (C-index: 0.751). Metformin use was independently associated with lower mortality risk (HR: 0.410, p = 0.019).

Conclusion:

The WATCH-DM(i) score is a robust prognostic marker of 5-year all-cause mortality in T2DM patients without HF and may serve as a practical tool for risk stratification in outpatient settings.

Plain Language Summary

Using a simple clinical risk score to identify people with type 2 diabetes at higher risk of death

Why was the study done? People with type 2 diabetes have a higher risk of early death, even when heart failure is not present. In daily clinical practice, risk assessment often relies on multiple tests that may be difficult to apply consistently. The WATCH-DM score is a simple clinical risk score originally developed to estimate heart failure risk in people with diabetes. It uses information routinely collected during clinic visits. However, it was unclear whether this score is also associated with the risk of death in patients with diabetes who do not have heart failure. What did the researchers do? The researchers studied 449 adults with type 2 diabetes receiving routine outpatient care in Taiwan. None had heart failure at the start of the study. Baseline clinical information, including age, body weight, blood pressure, kidney function, cholesterol levels, blood sugar control, and history of heart disease, was used to calculate the WATCH-DM score. Participants were followed for about five years using national death records to examine the relationship between the score and all-cause mortality. What did the researchers find? During follow-up, 39 participants died. Higher WATCH-DM scores were associated with a higher risk of death. For each one-point increase in the score, the risk of death increased by about 30%. People in higher score categories showed worse survival over time, especially after the first two years. The score was able to distinguish between lower- and higher-risk patients using information already available in routine care. What do the findings mean? These findings suggest that the WATCH-DM score may help identify people with type 2 diabetes who are at higher risk of death, even in the absence of heart failure. Because the score is simple and based on routinely collected data, it may be useful for risk stratification in outpatient settings. Larger studies in different populations are needed to confirm these results.