The Cox model of predicting mortality among melioidosis patients in Northern Malaysia

Abstract

Melioidosis is an infectious disease that is initiated by a bacteria recognized as Burkholderia pseudomallei . Despite the high fatality rate from melioidosis, there is a minimal published study about the disease in Malaysia. This study aimed to identify the prognostic factors of mortality among melioidosis patients in northern Malaysia. All inpatient patients who were admitted to Hospital Sultanah Bahiyah, Kedah and Hospital Tuanku Fauziah, Perlis with culture-confirmed melioidosis during the period 2014 to 2017 were included in the study. The study retrospectively collected 510 melioidosis patients from the Melioidosis Registry. Hazard ratio (HR) used in advanced multiple Cox regression was used to obtain the final model of prognostic factors of melioidosis. The analysis was performed using STATA/SE 14.0 for Windows software. From the results, among the admitted patients, 50.1% died at the hospital. The mean age for those who died was 55 years old, and they were mostly male. The most common underlying disease was diabetes mellitus (69.8%), followed by hypertension (32.7%). The majority of cases (86.8%) were bacteremic. The final Cox model identified 5 prognostic factors of mortality among melioidosis patients. The factors were diabetes mellitus, type of melioidosis, platelet count, white blood cell count, and urea value. The results showed that bacteremic melioidosis increased the risk of dying by 3.47 (HR: 3.47, 95% confidence intervals [CI]: 1.67–7.23, P = .001) compared to non-bacteremic melioidosis. Based on the blood investigations, the adjusted HRs from the final model showed that all 3 blood investigations were included as the prognostic factors for the disease (low platelet: HR = 1.76, 95% CI: 1.22–2.54, P = .003; high white blood cell: HR = 1.49, 95% CI 1.06–2.11, P = .023; high urea: HR = 2.92, 95% CI: 1.76–4.85, P < .001; and low level of urea: HR = 2.69, 95% CI: 1.69–4.29, P < .001). By contrast, melioidosis patients with diabetic had 30.0% lower risk of dying from melioidosis compared to those with non-diabetic (HR = 0.70, 95% CI: 0.52–0.94, P = .016). Identifying the prognostic factors of mortality in patients with melioidosis allows a guideline of early management in these patients, which may improve patient's survival.

Endemic melioidosis in central Taiwan—A longitudinal case cohort study

“…The second and third underlying diseases of our cases are hypertension (3, 27.2%) and anemia (3, 27.2%), including iron-deficiency anemia (case 3), normocytic hypochromic anemia by chronic renal failure (case 4), and myelodysplastic syndrome (case 11). Our epidemiologic data are consistent with findings that hypertension is the second common underling disease among 510 patients with culture-confirmed melioidosis in Malaysia ( 19 ). Few literatures have reported the association between anemia, especially thalassemia, and melioidosis ( 30 , 31 ), among which bacteremia and increasing mortality were identified ( 30 ).…”

“…Few literatures have correlated the laboratory profiles to the outcome of melioidosis patients such as mortality. Mardhiah et al ( 19 ) found significant correlation between abnormal laboratory profiles such as abnormal WBC (> 10,000 or < 4,000 cell/mm 3 ), decreased platelets counts (< 150,000 cells/mm 3 ), and increased BUN (> 21.8 mg/dL) and Cr (> 1.41 mg/dL) but not Hb, AST, and ALT with mortality. Chou et al ( 17 ) has also identified elevated serum creatinine (Cr) as one of the poor prognostic factors (survivors, 2.28 mg/dL vs. non-survivors, 3.34 mg/dL; p = 0.03).…”

Melioidosis and Burkholderia pseudomallei: progress in epidemiology, diagnosis, treatment and vaccination

“…A study of 510 patients with melioidosis from northern Malaysia showed very high rates of bacteraemia (86.8%), persisting high mortality (50.1%) and emphasized the importance of diabetes as the major risk factor for melioidosis (69.8%) [41]. A study from Sarawak in Malaysian Borneo confirmed the previous finding of predominantly gentamicin-susceptible B. pseudomallei (65% of clinical isolates) [42 ▪ ].…”

Review of Research on Mortality from Melioidosis in Malaysia

“…The mean age was 51.88 (15.19) years old. The same study reported the mean age of the melioidosis patient was 51.88 (15.19) years old [26]. In terms of ethnic groups, the majority who were affected were Malays, followed by Chinese and Indians (Ratio of 4.1:1.5:1).…”