{'fraction_non_alphanumeric': 0.02466091245376079, 'fraction_numerical': 0.0012330456226880395, 'mean_word_length': 5.444444444444445, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Basics of statistics – 2: Types of clinical studies

Introduction: Statistics is an unpleasant but essential part of an oncologist's academic life. This review is an attempt to simplify the concept of various types of clinical studies. Methods: Various books, articles, and online resources were used to gather information on types, definitions, clinical role, and brief methodology of various retrospective and prospective studies. Results: The collected information has been concisely put together along with relevant examples to make the manuscript reader-friendly. Discussion: This article is a brief account of various types of epidemiological and clinical studies used in medical research. Although some modifications are made time to time to suit the study requirements, basic framework remains the same.