National Database Data Collection
For the report, permission was obtained from the ministry of health to collect data from the six public hospitals in Kuwait on bariatric results and outcomes. Invitations were sent to bariatric surgeons working in these hospitals, of which 63 contributed to the data collection. This data was then submitted to a merged National Registry. A Direct Data Entry system, and an Upload-My-Data web portal were used to upload, merge, and analyze the data. Data was collected on 3,302 cases, of which 2,704 were primary procedures (Table 1). Data collection was demonstrably of a very high quality; over 87% of entries for patients having their primary operation had either no missing data or one missing data-item amongst a list of 10 obesity-related diseases assessed pre-operatively. All patients provided written consent prior to undergoing their procedure.
Definitions of Obesity Related Diseases
We aimed to set a standard baseline for defining obesity related diseases as to be able to compare between individual patients. Positive responses (data denoting patients who have the condition) were:
- Type 2 diabetes:
- Impaired glycaemia or impaired glucose tolerance.
- Insulin treatment.
- OAD & insulin treatment.
- Oral hypoglycaemics.
- Back pain or leg pain:
- Depression on medication.
- Impaired functional status:
- Can climb 1 flight of stairs without resting.
- Can climb half a flight of stairs without resting.
- Requires wheelchair or is housebound.
- Daily medication (H2RA or PPI)
- Intermittent medication.
- Intermittent symptoms; no medication.
- Treated hypertension.
- Untreated hypertension.
- Liver disease:
- Fatty liver.
- Mild steatosis.
- Severe steatosis.
- Sleep apnea:
- Increased risk of DVT or PE contains any one or more of:
- History or risk factor for DVTor PE.
- Venous edema with ulceration.
- Vena cava filter.
- Obesity| hypoventilation syndrome.
Obesity Surgery Mortality Risk Score
The Obesity Surgery Mortality Risk Score (OSMRS) stratifies patients undergoing bariatric surgery into three categories depending on how many of the following risk factors they possess:
- Male gender.
- Age ≥45 years at the time of surgery.
- BMI >50 kg m2.
- Risk factors for deep vein thrombosis / pulmonary embolism.
The patient is ascribed one point for each of the above risk factors and a cumulative score determined, giving a total score in the range zero to five; this score is normally grouped into one of three categories:
- Group A: score 0-1 (low risk)
- Group B: score 2-3 (moderate risk)
- Group C: score 4-5 (high risk)
Patients with higher OSMRS, are thought to be at a greater risk of post-operative complications and mortality. The score is only calculated when all of the required data are available in the operation record.
Descriptive statistics were used for the analysis of the data. The contributors were reassured that no statistical comparison would be attempted between different units. Furthermore, as data from different hospitals may only provide variable representation of the population, no comparative analysis was performed between hospitals.
On the whole, unless otherwise stated, the tables and charts in this report record the number of procedures. The numbers in each table are color-coded so that entries with complete data for all of the components under consideration are shown in regular black text. If one or more of the database questions under analysis is blank, the data are reported as unspecified in orange text. The totals for both rows and columns are highlighted as emboldened text. Some tables record percentage values; in such cases this is made clear by the use of an appropriate title within the table and a % symbol after the numeric value.
Rows and columns within tables have been ordered so that they are either in ascending order or with negative response options first (No; None) followed by positive response options (Yes; One, Two, etc.).
All entries with missing data are excluded from the analysis used to generate the graph. In the charts prepared for this report, most of the bars plotted around rates (percentage values) represent 95% confidence intervals. The width of the confidence interval provides some idea of how certain we can be about the calculated rate of an event or occurrence. If the intervals around two rates do not overlap, then we can say, with the specified level of confidence, that these rates are different; however, if the bars do overlap, we cannot make such an assertion.
Bars around averaged values (such as patients’ age, post-operative length-of-stay, etc.) are classical standard error bars or 95% confidence intervals; they give some idea of the spread of the data around the calculated average. In some analyses that employ these error bars there may be insufficient data to legitimately calculate the standard error around the average for each sub-group under analysis; rather than entirely exclude these low-volume sub- groups from the chart their arithmetic average would be plotted without error bars. Such averages without error bars are valid in the sense that they truly represent the data submitted; however, they should not to be taken as definitive and therefore it is recommended that such values are viewed with extra caution.