The response and transport intervals of an ambulance dispatch are affected by various factors. The present ambulance system relies on the driver’s experience, knowledge of local road map and estimations of directions. These may contribute to delays, misdirection and inefficient utilization of resources. The objectives of this study were to assess the effects of GPS navigation device on the response and transport time intervals of an ambulance service operating in urban setting. This was a three-month experimental study involving simulated ambulance dispatch based in a hospital. A total of 50 simulated cycles were constructed. Travel time, arrival time and distance were documented from each cycle. The median actual response time using map and GPS navigation device was 11.82 min and 10.47 min respectively. The median actual transport time using map and GPS navigation device was 11.00 min and 10.74 min respectively. The differences in response time and transport time between map and GPS navigation were not statistically significant (p= 0.215 and p=0.710). The application of GPS reduced the error value between estimated and actual response time by 8.73%. It also reduced the mean error value between estimated and actual transport time by 1.42%. The result shows that the GPS navigation device allowed for more accurate travel time estimation and its application in an urban setting such as Kuala Lumpur has the potential to reduce ambulance response time.
Emergency ; GPS navigation ; Prehospital care ; Response time ; Transport time

The response and transport intervals of an ambulance dispatch are affected by various factors. The present ambulance system relies on the driver’s experience, knowledge of local road map and estimations of directions. These may contribute to delays, misdirection and inefficient utilization of resources. The objectives of this study were to assess the effects of GPS navigation device on the response and transport time intervals of an ambulance service operating in urban setting. This was a three-month experimental study involving simulated ambulance dispatch based in a hospital. A total of 50 simulated cycles were constructed. Travel time, arrival time and distance were documented from each cycle. The median actual response time using map and GPS navigation device was 11.82 min and 10.47 min respectively. The median actual transport time using map and GPS navigation device was 11.00 min and 10.74 min respectively. The differences in response time and transport time between map and GPS navigation were not statistically significant (p= 0.215 and p=0.710). The application of GPS reduced the error value between estimated and actual response time by 8.73%. It also reduced the mean error value between estimated and actual transport time by 1.42%. The result shows that the GPS navigation device allowed for more accurate travel time estimation and its application in an urban setting such as Kuala Lumpur has the potential to reduce ambulance response time.

Objective: The natural history of asymptomatic (silent) gallstones has been inadequately studied. Existing information derives from studies based on oral cholecystography or relatively small sample sizes. We planned a retrospective cohort study in subjects with gallstones to determine conversion rates from asymptomatic to symptomatic. Methods: We extracted data from computerised databases of one government hospital and two private clinics in Malaysia. Files were scrutinised to ensure that criteria for asymptomatic gallstones were fulfilled. Patients were called on telephone, further questioned to confirm that the gallstones at detection were truly asymptomatic, and asked about symptoms that were consistent with previously defined criteria for biliary colic. Appropriate ethical clearances were taken. Results: 213 (112 males) patients fulfilled the criteria for asymptomatic gallstones and could be contacted. 23 (10.8%) developed pain after an average follow up interval of 4.02 years (range 0.1-11 years). Conversion rates from asymptomatic to symptomatic gallstones were high in the first two years of follow up, averaging 4.03±0.965 per year. Over time the conversion rates slowed, and by year 10 the annual conversion rate averaged only 1.38±0.29. Conversion rates were much higher for females compared to males (F:M hazard ratio 3.23, SE 1.54, p>z 0.014). The lifetime risks for conversion approached 6.15% for males, and 22.1% for females. Conclusion: In conclusion, asymptomatic gallstones are much more likely to convert to symptomatic in females than in males. Males in whom asymptomatic stones are discovered should be advised conservative treatment. Surgery may be preferable to conservative management if the subject is a young female.