This study was conducted with the aim of identifying the determinants of pre hospital delay of MI patients of Northern Bangladesh. Understanding the influencing factors of delayed hospital presentation after onset of myocardial infarction can aid in adoption of suitable strategies to ensure prompt quality treatment.
The median of total pre-hospital delay of the patients included in this study was 9 (IQR 13) hours, while median of decision time was 2 (IQR 2.8) hours. Referral time from private hospitals was higher than government hospitals. Overall, 39.5% patients admitted to RMCH within 6 hours. Patients who had typical clinical presentation, could suspect the symptoms as cardiac origin, visited qualified physicians and admitted directly to RMCH had more likely presented within 6 hours.
A study conducted in a Dhaka, the capital city of Bangladesh reported the mean pre-hospital delay of MI patients as 11.67 hours and about 77% of the patients reached the hospital within 6 hours (15). That study was conducted in private tertiary care hospital, where most of patients were from affluent families, who also showed lower pre-hospital delay in our study. The proportion of early presentation (within 6 hours) was 17.2%, as reported by a study conducted in a government tertiary care hospital situated in Chittagong in Southern part of Bangladesh (16). Situation of government tertiary care hospitals, the main service centers for mass population is quite similar all over the country. In developed countries pre-hospital delay of MI patients was much lower than Bangladesh. For example, among the patients included in the Global Registry of Acute Coronary Events (GRACE) study it was a median 3 hours and more than 70% patients presented to hospital within 6 hours (18). Even compared to neighboring country India, where median pre-hospital delay of MI patients were reported as 3 to 5.2 hours and almost 60% patients admitted to hospital within 6 hours (19,20), pre-hospital delay among our study population was much longer.
In our study cohort both younger and elderly patients had more likely a pre-hospital time of more than 6 hours. The conventional belief of people about myocardial infarction to be a disease of old age drives the younger patients to misinterpret the cardiac symptoms as less important ones like heartburn or peptic ulcer disease and this hinders them to take prompt action. Older age is a widely reported risk factor of prolong pre-hospital delay (16,18,21). No significant sex difference were found in case of pre-hospital delay in this study, which is consistent with other studies from both developed and developing countries including the Bangladeshi one (10,16,22–24). However, some other studies identified female sex as significant predictors of prolonged pre-hospital delay (12,25).
Patients’ from rural areas and lower income families were more vulnerable for delayed hospital admission though it was not related with their educational qualification. Rural area of residence (22,26) and lower socio-economic condition (27) were specified as risk factors of delayed hospital presentation due to delays in arranging money or proper transport in previous studies. Moreover, patients who had primary care facilities within 5 km were able to reach more likely within 6 hours. Similar finding is present in a previous studies where patients claimed longer distance of primary care center for late presentation (22,24,28). However the mode of transport (ambulance or general vehicle) was not associated with delayed hospital presentation in our study, though a study showed that patients who used private ambulance had shorter delay compared to those who used public ambulance or other transport (26). The role of educational status remains conflicting as some studies found higher educational qualification shortens the pre-hospital delay (12,22,27), while some others found no relation (26,29). Beside these, an interesting fact has brought forth by our study that middle class patients had a much higher odd of delayed hospital admission even more than lower income people. The cause of this bizarre finding is not clear. Further evaluation is suggested to describe the phenomenon.
Patients’ clinical symptoms are significant predictors of their delay to reach hospital. Patients who had predominantly severe chest pain more frequently presented to hospital within 6 hours compared to patients with other pain or atypical vague symptoms as found in other studies too (18,27). There is a high chance to misinterpret the atypical symptoms as non-cardiac origin, which discourage them to seek prompt medical help and increases the delay. Though difference between STEMI and non-STEMI was not significant, non-STEMI may present mostly with atypical symptoms, which can affect the pre-hospital delay of some patients.
Patients’ behavior and primary action after onset of symptoms was an important factor to determine pre-hospital delay. Patients who suspected MI were more likely to have early hospital presentation while those who considered the symptoms as nothing serious or waited for disappearance of symptoms were more likely to have delayed hospital presentation. This finding is similar to other studies where perceived susceptibility to MI was associated with shorter pre-hospital delay and misinterpretation of symptoms or pain resistance behavior were associated with prolonged pre-hospital delay (30,31). Visiting non-qualified or under-qualified medical practitioners or drug sellers or taking self-medication significantly increased pre-hospital delay. Such a trend is also present in India where visiting non-qualified practitioner was found to increase the delay (32). Though medical practice by non-qualified persons are rare in developed countries, consultation with non-medical personnel for advice or self-medication (33) and visiting GPs (19,24) markedly prolonged the pre-hospital delay there. Though the patients admitted directly to RMCH had a longer median decision to hospital arrival time, most of them were able to reach within 6 hours. The cause of this difference is clear as most of the patients who have visited government primary health centers were mostly from rural areas whereas the patients admitted directly were mainly from nearby urban areas. The finding is consistent with previous studies of different countries (11,24,34) though it was totally opposite to the other study of Bangladesh (16). They found visiting a primary care center had increased the rate of early presentation, however, they defined early presentation as admission within 12 hours of symptoms onset. Referral time was much higher from private hospitals compared to government hospitals, that caused these patients mostly delayed hospital presentation. Commercial attitude of private hospitals may be the cause of this prolonged referral time.
Role of chronic comorbidities on pre-hospital delay remains conflicting. In our study patients with diabetes mellitus or previous history of coronary arterial diseases were more likely to admit earlier compared to their counterpart while presence of hypertension didn’t have such positive correlation. But a number of studies evidenced the association between prolonged pre-hospital delay and diabetes or previous history of cardiovascular diseases (18,35). However, positive family history of cardiovascular disease undoubtedly aggravated the prompt action both in our and previous study populations (16,32). Perhaps the patients suffering from various chronic diseases are more aware and careful about their health which helps them to seek early medical care.
In-hospital mortality was higher among the patients who admitted after 6 hours, even after adjusting for other confounding factors like age, sex, type of MI and comorbidities that can play role in mortality. Similar finding was reported by another study among German population, where unknown or prolonged pre-hospital delay was associated with increased in-hospital death (36). Treatment efficacy of myocardial infarction decreases with time after onset of symptoms, that increases the risk of mortality (2,6,7).
The present study provides clear insight of the factors associated with pre-hospital delay of myocardial infarction patients of Northern Bangladesh. Patients’ behavior and health seeking action like considering the symptoms as nothing severe, self-medication or visiting non-qualified practitioners had increased the pre-hospital delay. These misconceptions and wrong care seeking action are most likely due to lack of knowledge and awareness about symptoms of MI or cardiac pain, which is reported in a study from Pakistan (8). Public awareness about symptoms of myocardial infarction should be raised so that misinterpretations can be reduced. Moreover, patients should be encouraged to visit qualified physicians or hospitals and medical practice of non-qualified personnel should be restricted to reduce misdiagnoses. Referral time, especially from private primary care hospitals should be reduced. Providing emergency diagnostic support like ECG and cardiac troponin to the primary care centers can reduce the referral time and thereby reduce the total pre-hospital delay. Proper use of ambulance service and the newly launched emergency number (999) can reduce the delay, though there is still no evidence in Bangladesh, but studies from other countries like Sweden reported that calling emergency medical care can reduce the pre-hospital delay (24).
The strengths of this study are inclusion of patients from the largest tertiary care hospital of Northern Bangladesh, who represent a large portion of national population. Moreover, patients’ symptoms, diagnoses and other clinical data were taken from the medical records that reduced the recall bias. The study will guide the further researches in this field.
The study is not beyond limitations. This was a cross sectional single-center study which doesn’t reflect the overall picture of the country. Time of onset of symptoms and primary action were based on patients’ statement. So recall bias is possibly a lagging of this study. Moreover, consecutive sampling of patients was not possible. Patients who were critically ill to interview or died within a short period of admission before conducting the interview were not included in the study. In-hospital complications other than death were not taken into account.