3.1 Study Area And Study Period
The study was conducted in the Amhara region in four comprehensive specialized hospitals. Felege Hiwot Comprehensive Specialized Hospital has 400 beds and around 15 adult outpatient departments (OPD) serving over 7 million people from the surrounding area. The OPD serves around 900 patients per day [23]. Debre Markos Comprehensive Specialized Hospital serves over 5 million people living in Debre Markos city and its surrounding [24]. Dessie Comprehensive Specialized Hospital serves more than 5 million populations [25]. Debre Berhan Comprehensive Specialized Hospital serves approximately 3 million catchment populations [26].
3.2 Study Design And Study Periods
A retrospective follow-up study was conducted to assess the incidence and predictors of AKI among type 2 diabetes patients from April 1 to 28, 2021.
3.3 Source Of Population
The source populations were all newly diagnosed Type 2 diabetes mellitus patients having follow-ups in Amhara region comprehensive specialized hospitals from January 1, 2014, to January 1, 2020.
3.4 Study Population
The study populations were all newly diagnosed Type 2 diabetes mellitus patients who were enrolled in Amhara region comprehensive specialized hospitals from January 1, 2014, to January 1, 2020, during data collection time.
3.4 Inclusion And Exclusion Criteria
3.4.1 Inclusion criteria
All adult T2DM patients having follow-ups in Amhara region comprehensive specialized hospitals from January 1, 2014, to January 1, 2020
3.4.2 Exclusion Criteria
Patients’ charts incomplete with major variables (serum creatinine, fasting blood sugar), lost medical records, patients who had AKI at the time of the diagnosis for T2DM and patients have no baseline records were excluded from the study.
3.5. Sample Size Determination
The minimum sample size was 544 using the command (stpowerlogrank, hratio (1.29) power (0.8) wd prob (0.1)) in STATA version 4 software by having the following assumption statistical power of 80%, 95% confidence interval and withdrawal of probability of 10% and adjusted of 1.29 from the previous study [27, 28]. Predictors and their hazard ratios for AKI among T2DM taken from previous studies were history of heart failure, prior bolus insulin regimen, baseline eGFR, and baseline HbA1c > = 9%.
Sampling Technique And Sampling Procedures
The study participants were filtered from the registration book in each hospital. All registered newly diagnosed T2DM patients from January 1, 2014, to January 1, 2020, were listed based on their medical record number and proportionally allocated the total sample size for each hospital. Then the sampling interval (K) was determined by dividing the total number of T2DM patients in six-year by the desired sample size from each hospital proportionally. Finally, the patient’s charts were filtered for every K interval from each hospital by using systematic random sampling.
3.7 Operational And Term Definitions
Acute Kidney Injury:- is an abrupt loss of kidney functions characterized by an increase in Serum creatinine by 0.3 mg/dl or 1.5 to 2 times baseline value which was diagnosed and recorded by clinicians on the patient card [29].
Incidence of AKI: - numbers of new onset of acute kidney injury after diagnosis of T2DM within the follow-up time.
Time to acute kidney injury
- the time from the diagnosis of T2DM to the first episode of acute kidney injury.
Event
- development of acute kidney injury at any time during the follow-up after the diagnosis of T2DM
Censored
the Patients who did not develop AKI until the end of the study, transferred out, died or lost to follow-up before experiencing AKI within the follow-up period.
Body Mass Index (BMI)
dividing the weight in kilograms by the square of the height in meters that can be categorized as underweight, < 18.5 kg/m2, normal, 18.5–24.9 kg/m2, overweight, 25-29.9 kg/m2, and obesity, ≥ 30 kg/m2[30]
Sepsis:- was defined as a clinically recorded sepsis on the patient’s chart or a combination of evidence of infection and 2 out of 3 criteria in quick Sequential Organ Failure Assessment (qSOFA) score(respiratory rate > 22b/minute, Glasgow coma scale < 15 and systolic blood pressure < 100 mmHg) per the 3rd International consensus definition released in 2016 [31].
Incomplete patient charts
refers to patient cards which were not recorded including unknown date of DM and AKI diagnosis.
Obesity
the patient’s baseline body mass index exceeded 30 kg/m2.
Poor glycemic control:-the patient card was recorded as poor glycemic control or the patients who had average blood glucose measurements on three consecutive visits > 130 or < 70 mg/dl [32].
3.8 Variables
Dependent Variable: incidence of AKI
Independent Variables:
The independent factors of the study are socio-demographic factors (age, sex, residence, occupation, marital status, educational status, and family history of diabetes mellitus), behavioral factors (smoking history, history of alcohol intake, and glycemic control), clinical factors and laboratory factors includes fasting blood sugar, level of HgA1C, infection, Diabetic Keto Acidosis, Hyperglycemia Hyperosmolar State, hypoglycemia, sepsis, comorbid conditions (dyslipidemia, myocardial infarction, chronic kidney disease, congestive heart failure, diabetic foot ulcer, chronic liver disease, diabetic nephropathy, and hypertension), BMI, and treatment-related factors including insulin, oral hypoglycemic agent, non-steroidal anti-inflammatory drugs, statin, beta-blockers, diuretics, angiotensin-converting enzyme inhibitors, and other nephrotoxic antibiotics).