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Preoperative Scoring System to Predict Difficult LC
            Table 1: Validity of a test in screening of disease  Table 2: History parameters distribution (total number of patients = 66)
                                Diagnosis                                                          Count      %
             Screening
             test results  Diseased     Healthy       Total     Age                    ≤50 years     49      74.2
             Positive  a (True positive)  b (False positive)  a + b                    >50 years     17      25.8
             Negative  c (False negative)  d (True negative)  c + d  Sex               Female        46      69.7
             Total         a + c         b + d     a + b + c + d                       Male          20      30.3
                                                                History of hospitalization   No      53      80.3
                                                                for cholecystitis
            Very difficult                                                             Yes           13      19.7
            •  Conversion
            •  Time taken is >120 min
            All the cases have had preanesthetic fitness, a routine work-up,
            and were taken up for surgery by a single surgeon. The duration
            of surgery was calculated from incision to port closure. We
            have calculated the preoperative degree of difficulty using our
            predictive parameters and are going to compare the outcome to our
            intraoperative findings. Duration of hospital stay was also tabulated.

            results
            Statistical Analysis
            Data were entered into Microsoft Excel data sheet and were
            analyzed using SPSS 22 version software. Continuous data were
            represented as mean and standard deviation. Categorical data was
            represented in the form of frequencies and proportions. Chi-square
            test was used as test of significance for qualitative data (Table 1). 14–16
            •  Sensitivity = a/(a + c) × 100 = True positive/True positive + False   Fig. 2: Bar diagram showing history parameters distribution
              negative
            •  Specificity = d/(b + d) × 100 = True negative/True negative +   Table 3: Clinical examination findings distribution (total number of
              False positive                                   patients = 66)
            •  Positive predictive value = a/(a + b) × 100 = True positive/True                    Count     %
              positive + False positive
            •  Negative predictive value = d/(c + d) × 100 = True negative/True   BMI  <25          21       31.8
              negative + False negative                                            25–27.5          15       22.7
            •  Diagnostic accuracy = a + d/a + b + c + d = True positive + True    >27.5            30       45.5
              negative/Total
                                                                Abdominal scar     No               25       37.9
            Specificity: It is the ability of a test to identify correctly those who   Infraumbilical  31    47.0
            do not have disease, i.e., true negative.                              Supraumbilical   10       15.2
            Sensitivity: Defined as possibility of a test to identify correctly all
            those who have the disease, i.e., true positive     Palpable gallbladder  No            66      100.0
            Negative predictive value (NPV): The proportion of patients who test
            negative who are actually free of the disease.        In the study, BMI was <25 in 21 (31.8%), 25–27.5 in 15 (22.7%),
            Positive predictive value (PPV): The proportion of patients who test   and >27.5 in 30 (45.5%) subjects. In total, 31 (47.0%) subjects had
            positive who actually have the disease.            infraumbilical abdominal scar, while 10 (15.2%) had supraumbilical
            Diagnostic accuracy: Is the ability of screening tests to detect true   scar and 25 (37.9%) had none. No subject presented with a palpable
            positives and true negatives in the total population studied.   gallbladder (Table 3, Fig. 3).
            p value: (Probability that the result is true) of <0.05 was considered   On sonologic findings, wall thickness was thin or <4 mm in 36
            as statistically significant after assuming all the rules of statistical   (54.5%) and thick ≥4 mm in 30 (45.5%). Pericholecystic collection
            tests.                                             was seen in 13 (19.7%) subjects, while 14 (21.2%) presented with an
            Graphical representation of data: MS Excel and MS word were used to   impacted stone (Table 4, Fig. 4).
            obtain various types of graphs such as bar diagrams, Pie diagrams,   In the study, as per the preoperative score system, 39 (59.1%)
            ROC curve, and scatter plots.                      were predicted to have an easy procedure, 23 (34.8%) were
            Statistical software: MS Excel, SPSS version 22 (IBM SPSS Statistics,   predicted to have a difficult procedure, and 4 (6.1%) to have a very
            Somers NY, USA) was used to analyze data.          difficult one (Table 5, Fig. 5).
               In the study, 49 (74.2%) subjects were ≤50 years and 17 (25.8%)   In the study, 11 (16.7%) had placement of drain (Table 6, Fig. 6).
            were >50 years, in which 46 (69.7%) were female and 20 (30.3%) were   There is a significant positive correlation between the
            male. In total, 13 (19.7%) had previous history of hospitalization for   preoperative score and the duration of surgery (p <0.001), and the
            cholecystitis, while 53 (80.3%) patients did not (Table 2) (Fig. 2).  duration of hospital stay.


                                                        World Journal of Laparoscopic Surgery, Volume 15 Issue 2 (May–August 2022)  133
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