Study setting
Ayder Comprehensive Specialized Hospital is found in Mekelle, Tigray regional state, Ethiopia. Mekelle is found at 783 Km north of Addis Ababa. Mekelle has total population 586,897. Mekelle city has nine governmental health centers, one referral Hospital and one military Hospital and two general hospitals. Ayder Comprehensive Specialized Hospital begins its referral and non-referral services in 2008 to the 9 million populations in its catchment areas of the Tigray, Afar and parts of the Amhara regional states in Ethiopia[14].
Ayder Comprehensive Specialized Hospital has capacity of about 500 beds in four major departments and other specialty units. Patient flow of ACSH is above170, 000 per year. The hospital provides hypertensive service in cardiac unit and stroke service in neurology unit. Medical ward, medical ICU, cardiac unit and diabetic unit were the study units[14].
Study design and period
A case-control study was conducted in Ayder comprehensive specialized Hospital, Tigray from February to April 2018.
Population and sampling
Cases were all sampled adult hypertensive patients with stroke diagnosed by the neurologist (consultant internist) or confirmed by brain imaging (CT-scan) or MRI. Controls were all sampled adult hypertensive patients without clinical evidence of stroke and without a history of stroke at ACSH during the data collection period. Cases with less than three follow-ups for hypertension treatment before first stroke occurrence and controls with less than three follow-ups for hypertension treatment were excluded. Pregnant mothers were also excluded from both cases and controls. The sample size was calculated using Epi Info version 7 statistical software using the following assumptions: a proportion of 10.7% and 24.1% of greater alcohol consumption was considered for controls and cases respectively[7] at 95% CI, 80% power. The case to control ratio was 1:4. Using those information 81 cases and 324 controls were selected but after adding 10% non-response rate the total sample becomes 445 of which 89 were cases and 356 were controls. Finally eligible cases and controls recruited using systematic sampling technique.
Data Collection Procedure
Record review of hypertensive and stroke patients was conducted to identify cases and controls. Information on socio-demographic data and behavioral risk factors for stroke was obtained from the patient or close relative (for unconscious cases) by interview.
Medical history like clinical duration of hypertension, type of stroke, the presence of stroke, and complication other than stroke was taken from the patient record. Height, weight, blood pressure, total cholesterol level and fasting blood sugar were taken during data collection.
During data collection data collector measures weight, height, blood pressure, as follows. Weight was measured in light closing and without shoes by calibrated UNICEF Seca digital weighing scale. Stadiometer in centimeter in erect position at a precision of 0.1cm without shoes was used to measure height. Mercury sphygmomanometer was used to measure blood pressure average of two measurements 5 minutes apart was recorded for those who we take BP during the data collection.
Assessment and definition of variables
Outcome variable: Stroke
Independent variables
Scio demographic included: age, sex, marital status, occupation, residency and educational status.
Behavioral factors included: Physical exercise, Smoking, alcohol, frequency of fellow up, salty diet, fatty food use, loss to fellow up, medication adherence
physical exercise physically active- if patients make regular physical activities 30 minutes and above, 5 days and above per week physically inactive- if patient is make physical exercise less than 30 minutes per week or less than 5 days per week[15]. , Medication adherence was assessed using Morisky medication adherence score to anti-hypertensive medications having eight questions each with yes=0 and No=l, adherent if they score 7-8 and non-adherent if they score <=6[16].
Alcohol drinker- a person who drinks 10.5 unites of alcohol and above per week[15].
Physical measurements and clinical factors: Fasting blood glucose (FBG), cholesterol level, blood pressure control, body mass index (BMI) and comorbidities. Normal FBG <126 mg/dl, raised FBG >=126 mg/dl[7].
Cholesterol level: normal if less than 200 and high cholesterol level 200 and above, BMI: underweight(less than 18.5), normal (18.5-24.9), over weight (25-29.9) and obese (30 and above). Systolic blood pressure: controlled(<140) and uncontrolled (>=140), diastolic blood pressure: controlled (<90) and uncontrolled(>=90)[17]. Comorbidities: yes if patient has any known medical disease.
Data analysis and management
Data were cleaned, coded, entered and analyzed using SPSS version 23. Summary statistics: frequencies tables and graphs were used to present for categorical variables and mean, median for continuous variables in both cases and controls.
First bivariate logistic regression was done to assess the association between each independent variable and the dependent variable. Variable with a P-value < 0.25 significance level in bivariate logistic regression was taken to multivariable logistic regression. Finally multivariable logistic regression was used to assess the association between independent variables with the dependent variable and to control confounding variables. Adjusted odds ratio and P-value <0.05 and with 95% CI was used to declare statistical significance.