Data Collection and Statistical Analysis
Every hospital has to have a system which can provide the hospital management with information necessary to plan and provide satisfactory patient care and efficiently manage the hospital. One of the main sources of hospital statistics is the medical record. Therefore, a suitably designed medical record system combined with a good patient registration system must be designed to suit these requirements.
Statistics are facts set down as figures. Preparing statistics involves the collection, analysis, interpretation, and presentation of facts as numbers. The hospital administrator and governing board use statistics to compare current operations with the past and as a guide in planning for the future.
Keeping up with current reporting system will save a great deal of unnecessary work. This will help to modify the collecting techniques so that information kept will be accurate and useful. Medical records are the primary sources of data used in compiling medical statistics.
Daily, monthly and annual reports
The daily and monthly analysis report concerning the professional care rendered to patients may indicate the number of patients registered newly as out patients, and the number of patients registered as revisit patients. This will include reports of admissions, discharges, number of surgeries performed and, the number of patients occupied as in-patients on a given day or month.
This report may be combined with a comparative report of the previous year, the same day and same month. If this is done on a routine manner the necessary additional data can be compiled on a daily, monthly and yearly basis and the information will be available when it is needed. The monthly analysis and comparative reports are important to the administration and governing board for future planning and control of activities.
Descriptive statistics
There is increasing emphasis on standardization of health statistics for valid intra hospital and inter hospital comparisons and analysis. In some hospitals, daily census reports are kept according to organized clinical services as well as nursing unit. Thus, for each service the daily statistical report will show the number of patients admitted directly or by transfer and the number of bed occupancy.
All statistical data gathered should be reviewed periodically so that obsolete or unused data no longer need to be collected. Since the medical records department sets the pattern for data collection, medical records in-charge should be aware of needs for new data related to activities newly developed in the hospital.
Some hospitals gather certain statistics for which there is no agreement among hospitals on definition. Such data will be useful only to those particular hospitals and to persons who are aware of the limitations of the definitions. Such data may be useful for internal operational purposes.
Out-patient services
Out-patient services data is extracted from the registers or system maintained at the registration counters in the out-patient department, specialty clinics and emergency services. The data will be useful to the extent that these registers or system contains pertinent information. Commonly used statistics pertaining to out patient services are,
- Number of new patients
- Number of revisit patients
- Speciality wise break-up of patients
- Unit wise break-up of patients
- Age and gender wise distribution of patients
- Out-patient diagnostic statistics
The formula for deriving this can be computed as follows:
| Daily average Out-patient visits = | Total no. of out-patient visits during the period |
| No. of op working days during the period |
Weekly predicting report
In order to create awareness among the staff of the hospital, a report anticipating the number of out-patients, in-patients and surgeries can be generated based on relevant figures during corresponding year of previous year. This statistical report can be prepared by adding expected growth rate to the actual data of the last year. During this preparation one has to keep in mind about the discrepancy between days and festivals of previous year and the current year.
This can be corrected by comparing with the last 3 year statistical data and anticipating the actual number of patients for the particular day or the week. Depending on the growth rate of out-patients, in-patients and surgeries of the current year, the prediction calendar can be prepared by adding 3% to 5% to the next year. This predicted report will be useful to plan each week for man power resources, granting casual leave to the staffs and to create awareness among the working staff.
Fortnight report
Based on the predicted weekly report and the actual number of patients treated in the week, a comparative report can be prepared to understand about the present growth trend of the hospital. This report can be prepared by collecting the number of out-patients, in-patients and the surgeries performed within fortnight. To understand the growth trend elaborately, this report can be further included with villages, districts, taluks and, cities.
This fortnight report can be prepared by comparing with actual patient visit of the last year with the number of patients anticipated this year which is compared with the current number of patients treated this year. This report will be helpful to the hospital authorities, doctors and the working staff to know the growth trend of their hospital.
Preparation of prediction calendar
For any institute as it grows, it becomes absolutely necessary to predict the number of patients visiting the hospital every day. This workup can be done by developing a calendar for every day which can be further developed on monthly basis for twelve months in a year. This daily predicted data for the upcoming year can be even printed as a book with the predicted data on one side and the actual number on the other side .
National holidays, festival and all important events which are going to take place in that New Year can also included in the prediction calendar. A column can be drawn in the calendar to compare the actual number of patient’s versus the predicted number. A comparative report with actual number of patients treated for the past three years with the current year can also be prepared for every month to know the growth trend of the hospital.
Comparative statistical reports
- The comparative report of professional performance provides comparative figures which are of value to the medical staff to evaluate its own performance, and to the governing board and the hospital administrator as a picture of professional performance of the hospital and medical staff
- The work of the current month can be compared with that of the same month of the previous year, and the total to date of the current year with that of the corresponding period of the previous year. The daily census provides some of the data for this report
- It is the responsibility of the medical records In-charge to keep up with the changing data requirements of the governing board to which the hospital must submit reports and have the data available when it is needed.
Common hospital percentages and rates
The term ratio is frequently used instead of percentage. A ratio expresses the quantitative relation of one thing to another, such as the relation of births to deaths. Careful attention must be given to all figures. Many errors in arithmetic occur because of misplaced decimal points.
There is one bit of common sense reasoning that will help medical record In-charge when computing a rate. A rate should be considered as the number of times something did happen compared to the number of times something could have happened. When expressing this ratio as a percentage, the number of times a thing happened is divided by the number of times it could have happened.
Infection rate
Every hospital must have a committee charged with the responsibility to investigate, control, and prevent infections. The primary purpose of evaluating infections is to determine the cause so that repetition may be avoided. Medical judgment is needed to establish the incidence of infections and the proper control measures to be taken. The hospital committee charged with infection control should set up procedures for the surveillance and reporting of infections.
Postoperative infection rate
The ratio of all infections in clean surgical cases to the number of operations performed in a particular period. The postoperative infection rate may also be required on statistical reports. If endophthalmitis rate is needed, it must be specified if this is to be computed out of all operations or out of all clean operations.
| Number of infections in clean surgical cases for a period | x100 |
| Number of surgical operations for the period |
Length of stay calculations
The length of stay (for one in-patient) is the number of calendar days from admission to discharge. To compute a patient’s length of stay, the date of admission is subtracted from the date of discharge when the patient is admitted and discharged in the same month. The average length of stay (average duration of hospitalization, average stay) is “the average length of hospitalisation of in-patients discharged during the period under consideration”
The formula for computing the average duration of in-patient hospitalisation is
| Total length of stay (No. Of days stay) |
| |
| Total discharges |
Average daily in-patient census (average daily census)
The average daily in-patient census records the average number of in-patients present each day for a given period of time. To arrive at the average number of in-patients in the hospital, the total in-patient service days for the period must first be determined. The formula to obtain the average daily in-patient census for a whole hospital is
| Total in-patient service days for a period |
| |
| Total number of days in the period |
In-patient bed occupancy ratio
The in-patient bed occupancy ratio can be computed at any specified point in time or for any specified day. To compute the percentage for a specified day, the in-patient service days for that day are multiplied by 100 and divided by the in-patient beds available for the day. To obtain the in-patient bed occupancy ratio as a daily average in a longer period, the formula is
| Total in-patient service days for a period | x 100 |
| Total number of in-patient beds available x Number of days in the period |
Anesthesia death rate
The ratio of anesthesia deaths caused by anesthesia deaths caused by anesthetic agents for a period to the number of anesthetics administered for the period. Since anesthesia deaths occur frequently, this rate will usually be computed on an annual basis. An anesthetic death is defined as a death that takes place while the patient is under anesthesia or which is caused by anesthetics or other agents used by an anesthetist or anesthesiologist in the practice of his profession. The number of anesthetics administered is obtained from the anesthesiology department or the operating room. The formula for figuring this percentage is:
| Total number of deaths caused by anesthetic agents for a period | x 100 |
| Total number of anesthetics administered for the period |
Computerised statistical reporting system
- In most hospitals the collection of statistical information is done with the assistance of a data processing system
- Regardless of whether information is processed and stored in the hospital’s computer or contracted to an outside data processing service, a large amount of valuable hospital data can be retrieved for use in tracking patient care, research and planning efforts, and reporting to other health related organisations
- The daily census sheets are often the first automated venture made by a facility when converting from a manual to computerised statistical reporting system. From the census information fed into the computer, a daily list of admissions, discharges and occupancy list is printed and used
Presentation of quality control data
- Feeding patient information into a computer for processing and storage does not diminish the medical record department’s responsibility for the accuracy and reliability of collected data. It is safe to assume that the computer can perform simple mathematical functions accurately.
- Quality control of input data however remains the responsibility of the medical records technician
- Duplication of effort may be avoided if one consolidated report satisfies everyone’s needs
- In a manual system, evaluation of the percentage of clerical error is an important consideration
- Routine quality control studies can ensure that the necessary collection of statistical information is done in an effective and cost-efficient manner
- The reports from the medical record department to the hospital administrator are forms of communication
- One needs to keep in mind that reports should be simple, highlighting important facts, and to make them as readable as possible
- The medical record In-charge who supplements these tables with such visual aids as graphs, bar charts, and pie diagrams, or any other pictograph that illustrates clearly what the figure indicate, is to be admired
- Each and every report must be titled and dated with short and clear information
- This additional effort makes a report much more interesting and attractive and easy for the reader to review and interpret
Summary
This chapter covers the basic data needed by the governing board, hospital administrator, and the working staff. The medical record department will receive requests for data that are not kept routinely, but, such requests can be fulfilled if data are kept in sufficient detail. Assistance must be provided to the medical staff and hospital committees in analyzing and interpreting the data collected.
In developing a program involving collection of statistical data, emphasis must be placed on routine, systematic collection and recording of information. The information must be stored in such a way that the medical record In-charge can retrieve it easily and present it accurately. Medical record personnel working in health care institutions which have access to computers will be able to collect much more than the basic data and will be able to retrieve them more readily in usable form. No matter what method of collecting statistics the medical record In-charge or technician employs, the meanings of terms must be defined to make the information understandable. Different definitions of the same word may be used and required for different purposes. When statistics are approached with a questioning attitude and are accurately reported, they will be valuable to all who use them.
Key points to remember
- Medical records are the primary sources of data used in compiling medical statistics
- Preparing statistics involves the collection, analysis, interpretation, and presentation of facts as numbers
- The daily, monthly analysis report concerning the profession care rendered to patients should indicate the number of patients registered newly as out patients, and the number of patients registered as revisit patients.
- All statistical data gathered should be reviewed periodically so that obsolete or unused data no longer need to be collected.
- The data of the current month can be compared with that of the same month of the previous year, and the total to date of the current year with that of the corresponding period of the previous year
- This monthly analysis and comparative report are important to hospital administration and the governing board for future planning and control of activities
- Routine quality control studies can ensure that the necessary collection of statistical information is done in an effective and cost-efficient manner
- The reports should be simple, highlighting important facts with visual aids as graphs, bar charts, and pie diagrams, or any other pictograph that illustrates clearly what the figure indicates. This effort makes a report much more interesting and attractive and easy for the reader to review and interpret
Student exercise
Answer the following
- Describe the method of collecting daily, monthly and annual statistical reports?
- How the data are compiled for out-patient services? Mention the commonly used statistics pertaining to out-patient services.
- Describe the method of predicting weekly report and preparation of calendar for the year?
- Explain how the fortnight report will be useful to the working staff and the management and the method of preparing it?
- Monthly analysis and comparative report are essential to the governing board. Explain how it is important.
- Define the following terms:
- Post-operative infection rate
- Average length of stay
- In-patient bed occupancy ratio
- Anaesthesia death rate
- Define computerised statistical reporting system? Explain how quality control studies can be done to evaluate its accuracy and reliability?
