AJNS

LETTERS / LETTRES
 
STROKE MORTALITY IN A TEACHING HOSPITAL IN SOUTH-WEST OF NIGERIA



  1. Faculty of Clinical Sciences, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, NIGERIA

E-Mail Contact - KOMOLAFE Morenikeji Adeyoyin : adeyoyin2001 (at) yahoo (dot) com


ABSTRACT

Stroke, a major cause of morbidity and mortality is on the increase and with increasing mortality. Our retrospective review of all stroke admissions from 1990 - 2000 show that cerebrovascular disease accounted for 3.6% (293/8144) of all medical admissions; has a case fatality rate of 45% with the majority (61%) occurring in the first week; mean age of stroke deaths was 62 years (SD +/- 13); and severe as well as uncontrolled hypertension is the most important risk factor. Community based programmes aimed at early detection and treatment of hypertension in addition to screening for those with high risk factors should be put in place.

INTRODUCTION

Stroke is a major cause of morbidity and mortality in black Africans, responsible for between 0.9 to 4% of total admissions to hospitals and 0.5 to 45% of neurological admissions1. Recent studies have shown stroke to top the list of admissions into the medical wards2. In Europe and North America there is a progressive decline in Stroke mortality rates from the 1950s to 1980s following which the rates have stabilized. In the MONICA study3, the case fatality ranged from 15-50% with an average of 30%. The highest case fatalities were in the Eastern European countries while the lowest occurred in the Nordic countries. In the United States, there has been a decrease in the case fatality of stroke from 15.7% in 1971 -82 to 11.7% in 1982-92, a change that has been attributed to decline in the incidence due to primary and secondary prevention and improved treatment. In a Nigerian community-based study the age-adjusted mortality rate of stroke is higher than that of the USA, most likely due to the increasing burden of hypertension and diabetes, lack of resources and limited access to medical treatment.

PATIENTS AND METHODS

We retrospectively reviewed the hospital records of all in-patients with clinical diagnosis of stroke admitted and managed in the neurology unit of the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria between 1990 and 2000. One hundred case files were available for review and the data obtained were analyzed using the statistical Package for Social Sciences (SPSS) version 11.0.

RESULTS

Stroke admissions accounted for 3.6% (293/8144) of all medical admissions, and with a case fatality rate of 45% (range 28.8%-56.0%) Table 1. Of the 132 deaths, only 100 case records were available for review. The male to female ratio was 1.9:1. Stroke was uncommon below 40 years (6%) whereas more than half of the deaths (54%) occurred in the 6th and 7th decades. The majority of the deaths (61%) occurred within the first 7 days of admission. The most common risk factor for stroke was hypertension (78%), followed by diabetes mellitus (9%), and cardiac arrhythmia (4%). Majority (69%) had severe hypertension (JNC stage 2) at presentation. The mean systolic blood pressure among the stroke deaths was 170 (SD +/- 42), and the mean diastolic blood pressure was 106 (SD +/- 29). Factors contributing to mortality include septicaemia 52%, hypotension 12%, renal failure 5%, and recurrent strokes in 23%.

DISCUSSION

Stroke remains an important cause of hospital related deaths. Previous workers noted a rise in the frequency and mortality in Nigerian patients with stroke1. Stroke was responsible for 3.6% of medical admissions, similar to the findings of Osuntokun (0.9 to 4%)4. Although there was a wide variation in the yearly case fatality, the average case fatality rate of 45.0% is still very high compared to figures elsewhere. There is consistent reduction in stroke incidence and mortality in the western world due to risk factor modification3. Our findings differ from the global trend with yearly increases in the frequency of stroke admissions and case fatality. This is not immediately obvious from table 1, but from 1995, hospital services in Nigeria have been epileptic, and in a year the hospital may not be admitting patients for up to 6 months. This recent increase may be attributed to change in lifestyle with the adoption of a sedentary lifestyle, and increased consumption of refined diets. The high mortality rate noted in this study may just be the tip of the iceberg as a substantial proportion of stroke patients die at home or before reaching the hospital. The diagnosis of stroke was clinical and none of the patients had CT scan. CT scan is important in differentiating the various types of stroke and to exclude common conditions such as brain tumor and subdural haematoma which mimic stroke. Severe and uncontrolled hypertension was commonly associated with the stroke deaths. Hypertension is often not diagnosed prior to stroke episode in about 60% of patients who show no other evidence of hypertensive disease4. The fact that majority of the patients had severe hypertension (JNCII) may contribute to the high case fatality. Mortality also increases with age, not unrelated to many other underlying medical conditions in the elderly. Since global trends of reduction in the mortality rate of stroke has been attributed to primary and secondary prevention and treatment5, there is the need for governments, particularly of the developing nations to give more attention to health education, increase budgetary allowances to health to make health care available, accessible and affordable. There is also the need for a multidisciplinary approach to treatment and the establishment of stroke teams proven to reduce intra-hospital mortality. Community based studies are needed to document the trends in incidence and mortality in our environment. A prospective and multicenter study with radiological and autopsy diagnosis is needed to eliminate limitations such as incomplete and missing data.

Year Total medical admissions Stroke Admissions % of total admissions Stroke deaths Case fatality rates (%)
1990 702 25 (3.56%) 8 32.0
1991 715 19 (2.66%) 10 52.6
1992 767 26 (3.39%) 10 38.5
1993 731 22 (3.01%) 9 40.9
1994 726 25 (3.44%) 14 56.0
1995 855 32 (3.74%) 15 28.8
1996 774 29 (3.75%) 16 55.0
1997 728 21 (2.89%) 11 52.4
1998 785 28 (3.57%) 14 50.0
1999 714 36 (5.04%) 13 36.1
2000 647 30 (4.64%) 12 40.0
Total 8144 293 (3.60%) 132 45.0

REFERENCES

  1. OSUNTOKUN BO. Stroke in the African. Afr J Med Sci 1977; 6:64-78.
  2. TALABI AO. A 3-year review of Neurologic admissions in the University College Hospital Ibadan, Nigeria. W Afr Med J 2003;22: 150-151.
  3. TUNSTALL PH, for the WHO MONICA Project Principal Investigators. The World Health Organization MONICA Project (monitoring trends and determinants in cardiovascular disease): a major international collaboration. J Clin Epidemiol 1988; 41:105- 114.
  4. OSUNTOKUN BO. Epidemiology of stroke in Blacks in Africa. Hypertension Res 1994; 17 suppl. J: S1-S10.
  5. BONITA R, STEWART A, BEAGLEHOLE R. International trends in stroke mortality: 1970-85. Stroke 1990;21: 989-92.


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ISSN: 1992-2647