Statistics


Article Author:
Marlon Bayot


Article Editor:
Ibrahim Abdelgawad


Editors In Chief:
Wanda Wright
Cynthia Oster


Managing Editors:
Orawan Chaigasame
Carrie Smith
Abdul Waheed
Frank Smeeks
Kristina Soman-Faulkner
Benjamin Eovaldi
Radia Jamil
Sobhan Daneshfar
Saad Nazir
William Gossman
Pritesh Sheth
Hassam Zulfiqar
Steve Bhimji
John Shell
Matthew Varacallo
Ahmad Malik
Mark Pellegrini
James Hughes
Beata Beatty
Hajira Basit
Phillip Hynes
Kavin Sugumar


Updated:
2/18/2019 10:28:58 PM

Definition/Introduction

Statistics, as a science, is the scientific process of acquisition and management of a given set of data. In the medical field as well as in other life sciences, the term “biostatistics” is often used instead to emphasize its application to medicine and health. Statistics is used not only to provide information on the given health situation but to guide healthcare professionals in the decision-making process whether as part of the research study or as part of clinical work.

The application of statistics undergoes a series of steps creating a cycle of scientific activities. Usually, it begins with the acquisition of health data. This collection of data involves the gathering of health-related information through the use of data collection tools (e.g., survey questionnaires) to accurately acquire details which are pertinent to a given study. Collecting data directly from the respondents are termed as primary sources of data. If the researcher wants to use a given set of data that were collected beyond the scope of the study (e.g., vital statistics and health statistics), then these are termed as secondary sources of data. Before moving on to the next step of the process, accuracy and reliability of the data collection must be confirmed since any alterations or misinformation during this process would inevitably affect the analysis and interpretation of data on hand.

Data management, on the other hand, employs the organization and analysis of health data. Data can be organized in numerous ways, so, every researcher should only use methods depending on the specific goal of the study. For example, if the statistical data must be interpreted as individual units, it can be organized in the form of a raw data or data series (e.g., arranged in arrays or alphabetical order). This is usually done in studies having a small population (e.g., case studies, case series).  Otherwise, if the data needs to be described using a frequency distribution, it can be organized either as discrete or continuous data series using frequency tables. This collection process is frequently used in studies with larger study population. It is important to note that the best method of organizing statistical data primarily depends on the type of variable (e.g., qualitative or quantitative) and its level of measurement (e.g., nominal, ordinal, interval, ratio). Arriving at all possible data organization may not be necessary if, and only if, this will give the best information to the researchers about the objectives of the study.

The use of appropriate methods to organize data will lead to its accurate analysis. In descriptive data analysis, the use of narratives, tables, graphs, and charts can be sufficient to describe the study variables. In the inferential analysis, the researcher needs to either make an estimation of specific clinical or health parameters or perform a hypothesis testing. Several versions of data analysis software are available for use according to the type of research work.[1]

Eventually, accurate and reliable interpretation follows as a result of a properly carried out data analysis, as this step focuses on the generation of correct information based on the findings while relating it to the context of the topic under study. The current generation of discoveries, conclusions, and hypotheses will make future researchers capable of studying its underlying issues and restarting the statistical process, creating a continuous cycle of collecting, organizing, analyzing and interpreting data.

Issues of Concern

There are some issues on statistics as applied in the healthcare setting. Most of these issues are encountered from research studies, both from community and clinical researches. These include, but not limited to, the following points enumerated below:

Data collection

  • The integrity of the data collection[2] 
  • Data collection about “dying patients”[3]
  • Advantages and disadvantages of data collection approaches[4][5] 
  • Researcher-participant partnership[6]

Data organization (and presentation)

  • Use of relational database[7]
  • Creation of frequency distribution: from tabulation to graphical representation[8]
  • Type of charts based on the data analysis method[9]

Data analysis

  • Statistical analysis of small area health studies[10]
  • Misconceptions about data analysis and statistics[11]
  • Limitation of data and its measurement in studying health disparities[12]
  • Ethical issues on the use of secondary data analysis[13]

Data interpretation

  • The interpretation of p-values[14][15] 
  • Steps to data summarization[16]
  • Differences in the application of clinical and statistical significance[17][18] 

Clinical Significance

Although this is not a definite part of the statistical process according to previous and current references on the topic, the "utilization of data in the healthcare setting" can still be an additional part of an overall process.  The use of relevant statistical findings and conclusions are vital in the decision-making process of both internal and external stakeholders of health.

Just as there is a data analysis plan made before any study is implemented, a careful plan is required on how statistical results shall be shared with the appropriate audience. Graphical presentation as used in descriptive studies can effectively aid in the understanding of both technical and non-technical staff. The introduction of statistical output in presenting the results to the stakeholders may not always be beneficial at all times. Instead, the meaning and relevance of the statistical test and the practical application of its conclusion should be given more emphasis. Determining the recipients of the statistical findings will help in defining the method of disseminating specific statistical information.[19]

Generally, the importance of statistics as a tool for the execution of health research and the development of new knowledge and understanding in the healthcare practice has already been proven both in the past and in contemporary situations. While statistics carries its specific language, like medicine, science and other technical areas also do, each healthcare professionals in clinics, hospitals, laboratories, and health industries must not be hindered from knowing the basic concepts of statistics. It must be always emphasized that the application of statistics in health and medicine is meant to help the healthcare team to have a deeper understanding of health-related variables and events, and not to confuse them in any other way, for instance, due to the misuse and abuse of statistics[20], which could, indirectly yet clinically, impact patient outcomes in the future.


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Statistics - Questions

Take a quiz of the questions on this article.

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What is the mean in a sample of 1,4,5,5,and 5?



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What is sensitivity?



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What is specificity?



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Twelve new cases of prostate cancer occurred among 1000 people followed for two years. What is the incidence rate of prostate cancer?



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In a population, the mean total cholesterol is 200 mg/dL with a standard deviation of 10 mg/dL. What percentage of the population will have a total cholesterol > 220 mg/dL?



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The number of pets surveyed in five families was 1, 2, 3, 5, and 6. What would be the median?



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Five patients in remission from non-Hodgkin lymphoma have been for 2, 4, 6, 8, and 10 months. What is the mean of these values?



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The last five glycosylated hemoglobin tests in a diabetic patient have been 10, 8, 9, 9 and 9.5. What is the mode?



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The probability of X is 0.4, and the probability of Y is 0.2. What is the probability of X or Y given they are mutually exclusive?



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The probability of X is 0.4, and the probability of Y is 0.2. What is the probability of X or Y given they are independent?



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What Is the median in this group of experimental numbers: 80, 90, 120, 150, 170, 200 and 220?



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What is the mode in this group of experimental numbers: 150, 200, 200, 210 and 250?



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What is the mean in this group of experimental numbers: 900, 1000, 1200 and 1500?



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The distance a patient ambulates during therapy is 12 meters, 45 meters, 31 meters, 52 meters, and 40 meters. Select the median distance.



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A study examines the change in heart rate that occurs after chest physical therapy in a patient with pneumonia. Which of the following is the dependent variable?



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Statistics - References

References

Ali Z,Bhaskar SB, Basic statistical tools in research and data analysis. Indian journal of anaesthesia. 2016 Sep;     [PubMed]
Moody LE,McMillan S, Maintaining data integrity in randomized clinical trials. Nursing research. 2002 Mar-Apr;     [PubMed]
Fowler FJ Jr,Coppola KM,Teno JM, Methodological challenges for measuring quality of care at the end of life. Journal of pain and symptom management. 1999 Feb;     [PubMed]
Saczynski JS,McManus DD,Goldberg RJ, Commonly used data-collection approaches in clinical research. The American journal of medicine. 2013 Nov;     [PubMed]
Sarkies MN,Bowles KA,Skinner EH,Mitchell D,Haas R,Ho M,Salter K,May K,Markham D,O'Brien L,Plumb S,Haines TP, Data collection methods in health services research: hospital length of stay and discharge destination. Applied clinical informatics. 2015;     [PubMed]
Holden RJ,McDougald Scott AM,Hoonakker PL,Hundt AS,Carayon P, Data collection challenges in community settings: insights from two field studies of patients with chronic disease. Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation. 2015 May;     [PubMed]
Sestoft P, Organizing research data. Acta veterinaria Scandinavica. 2011;     [PubMed]
Manikandan S, Frequency distribution. Journal of pharmacology     [PubMed]
In J,Lee S, Statistical data presentation. Korean journal of anesthesiology. 2017 Jun;     [PubMed]
Wakefield J,Elliott P, Issues in the statistical analysis of small area health data. Statistics in medicine. 1999 Sep 15-30;     [PubMed]
Motulsky HJ, Common misconceptions about data analysis and statistics. British journal of pharmacology. 2015 Apr;     [PubMed]
Bilheimer LT,Klein RJ, Data and measurement issues in the analysis of health disparities. Health services research. 2010 Oct;     [PubMed]
Tripathy JP, Secondary Data Analysis: Ethical Issues and Challenges. Iranian journal of public health. 2013 Dec;     [PubMed]
Nahm FS, What the {i}P{/i} values really tell us. The Korean journal of pain. 2017 Oct;     [PubMed]
Tanha K,Mohammadi N,Janani L, P-value: What is and what is not. Medical journal of the Islamic Republic of Iran. 2017;     [PubMed]
Yan F,Robert M,Li Y, Statistical methods and common problems in medical or biomedical science research. International journal of physiology, pathophysiology and pharmacology. 2017;     [PubMed]
Ferrill MJ,Brown DA,Kyle JA, Clinical versus statistical significance: interpreting P values and confidence intervals related to measures of association to guide decision making. Journal of pharmacy practice. 2010 Aug;     [PubMed]
West CP,Dupras DM, 5 ways statistics can fool you--tips for practicing clinicians. Vaccine. 2013 Mar 15;     [PubMed]
Kass RE,Caffo BS,Davidian M,Meng XL,Yu B,Reid N, Ten Simple Rules for Effective Statistical Practice. PLoS computational biology. 2016 Jun;     [PubMed]
Thiese MS,Arnold ZC,Walker SD, The misuse and abuse of statistics in biomedical research. Biochemia medica. 2015;     [PubMed]

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