Dental Statistics Made Easy

Nigel C. Smeeton

• Publisher: Chapman and Hall/CRC
• Year: 2016
• Print ISBN: 9781138469662
• eBook ISBN: 9781498775083
• Topic: Mathematics
• Subtopic: Probability & Statistics
• Index: Mathematics

This essential textbook presents the basics of dental statistics in an accessible way, combining explanation in non-technical language with key messages, practical examples, suggestions for further reading and exercises complete with detailed solutions. There is an emphasis on the principles and application of statistics without the use of algebra.

The statistical material is strongly rooted in practical examples drawn from a wide range of journal articles representing both dental health care delivery and clinical dentistry. The perspective is international, with papers drawn from a variety of settings around the world. Many articles are recent and report contemporary developments in dental care.

The intended audience includes dental students and practitioners, those engaged in dental research and other health care professionals. For students and tutors, it covers the undergraduate curriculum, and the exercises and solutions make it ideal for course use. For practitioners and researchers it provides the first principles of study design, accessing the dental literature, and the preparation and publication of original dental research.

CHAPTER 1

Introduction

Dentistry is a rapidly evolving profession. Methods of patient management are under constant scrutiny and there is a wide range of views about the funding of dental care. New methods of diagnosis and treatment continue to be developed. The current rapid advances in technology will without doubt accelerate this process.

Before new methods can be considered suitable for general implementation, they need to be compared with current techniques. Such studies often yield much detailed information that has to be evaluated. For example: Is the new technique “better”? Are there any side effects? What are the cost implications? In order to resolve these questions properly, a multidisciplinary team is required that includes (for example) psychologists, sociologists, economists, and statisticians. Dental statistics plays a crucial role in the design and evaluation of such studies. Once the findings have been summarized, they need to be applied to the practice of dentistry in general. Statistical methods are essential in order to achieve this goal.

It is the responsibility of the qualified dentist to keep abreast of developments in dental practice, particularly those that are relevant to the quality of patient care. In many countries, practicing dentists are required to undertake continuing professional development (CPD) in order to remain registered. Information about dental care is more readily available to the general public than ever before (e.g., on the Internet), and some patients will ask their dentist detailed questions about their treatment. A basic knowledge of statistics can enable the dentist to become better informed about dental issues. In particular, it can assist in the following.

The Understanding of Papers in Journals

One component of many CPD programs is the critical reading of a number of dental articles. Dentists might also need to evaluate papers on themes related to their particular specialty. Articles of general interest to dentists appear in high-circulation dental periodicals such as the British Dental Journal and the Journal of the American Dental Association. Papers of interest to a particular field of dentistry tend to appear in specialist journals such as Community Dental Health, the International Journal of Paediatric Dentistry, and the Journal of Oral and Maxillofacial Surgery. Occasionally, dental articles of potential interest to all clinicians are published in high-circulation medical journals such as the British Medical Journal, the Journal of the American Medical Association, and The Lancet. Many papers (both general and specialist) make use of statistical terms; some knowledge of statistics will therefore make it much easier to glean useful information from them. It is unwise to have blind faith in everything that is published; journal articles can contain errors and a little knowledge of dental statistics can assist in the detection of some of them.

Day-to-day clinical decisions should be based on the current evidence (this is known as evidence-based dentistry). To facilitate this process, the journal Evidence-Based Dentistry publishes abstracts of important advances in the practice of dentistry. Many of these summarize the results of a comprehensive search of literature databases such as MEDLINE, a continually updated source of information on articles from medical, dental, and biological journals (see Chapter 17). This relieves the busy dental practitioner of what can be a very time-consuming task.

Clinical Audit

In many dental practices, patients complete a short information sheet when they register. This usually requests the patient’s name, address, gender, date of birth, current medical conditions, and medications prescribed. A dental record is created for that patient. Information regarding the condition of the patient’s teeth, investigative procedures, and treatment received is added after each visit by the patient. It is good practice to audit dental records to assess (for instance) procedures performed, patient referrals, and methods of payment for care. In many countries, dental practices operate in a free market and careful financial auditing is essential.

Suppose that a new method of treatment is adopted at a dental practice. The partners will need to evaluate its success (or otherwise) from the records of patients in the practice. If the findings are in the form of numbers, the use of statistical methods is the most appropriate form of evaluation.

Health Services Research

Increasingly, general dental practices are being linked to dental schools for the purpose of research studies in the community. Practices can act as data-collecting centers for projects based, for instance, in a dental school. In addition, if they so wish, dentists can learn about research methods and gain assistance with the planning of their own investigations, thus becoming active researchers in their own right.

The view that few dental students or practitioners are interested in participating in research is becoming increasingly outdated. Dental practice research networks have developed into a major resource (Heasman et al. 2015) at local, regional, and national dental practice levels. Some involvement in research activities is becoming increasingly commonplace. The origin of one of the earliest general dental practice networks in the United Kingdom (UK) is described below.

Example 1.1

Kay, Ward, and Locker (2003) describe the development of a general dental practice research network in the northwest of England. Some general dental practitioners in the region were interested in participating in research in an active way beyond data collection alone. Following funding from a research and development initiative for primary dental care, a series of workshops was organized. These were aimed at developing the research skills of practitioners in areas such as literature retrieval, critical appraisal of articles, questionnaire design, applying for research funding, and data analysis. A further goal was to stimulate the practitioners’ own research ideas, so that the n...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Contents
• Preface to the Third Edition
• Preface to the Second Edition
• Preface to the First Edition
• 1 Introduction
• 2 Planning a Study
• 3 Types of Study in Dental Research
• 4 Sampling
• 5 Randomized Controlled Trials
• 6 Ethical Considerations
• 7 The Normal Distribution
• 8 Diagnostic Tests
• 9 Sampling Variation
• 10 Introduction to Hypothesis Tests
• 11 Comparing Two Means
• 12 Dealing with Proportions and Categorical Data
• 13 Comparing Several Means
• 14 Regression, Correlation, and Agreement
• 15 Non-Normally Distributed Data
• 16 The Choice of Sample Size
• 17 Evidence-based Dentistry
• 18 Statistical Refereeing
• Appendix
• Solutions to Exercises
• References
• Index