The Minister of Health of Madagascar gave permission for the surgical programs including the evaluation and Mercy Ships Institutional Review Board approved the study (MS-2016-003). The requirement for individual written consent was waived.
Study setting
Mercy Ships is a surgical NGO that delivers free surgeries, training and quality improvement initiatives in coastal sub-Saharan African countries [19]. The ship, the Africa Mercy, visits countries at the invitation of the head of State typically spending 10 months in one country before moving to another country. Using 5 operating rooms and 82 beds, a range of surgical services are provided for approximately 1200 patients per field service. Between September 2015 and February 2016, Mercy Ships was based in Madagascar and undertook five specialist surgical programs: general surgery; women’s health; maxillofacial surgery; orthopaedic surgery; and plastic surgery. The different surgical specialities took place in different months during the study period, with only three specialities occurring at any one time.
Study design and patient population
We aimed to evaluate pre- and postoperative disability in 500 consecutive patients in Madagascar using a prospective observational design. To ensure an even distribution, we aimed for 100 consecutive patients per speciality. Sample size was based on available results from the pilot study [20], which calculated 83 patients per group at a power of 80% and alpha of 0.05. All patients gave verbal voluntary consent to participate and the only exclusion criteria was inability to speak French or Malagasy.
Outcome measure
This study uses the WHODAS 2.0 as a PRO tool to evaluate the impact of surgery on pre- and postoperative disability across a range of surgical specialties.. WHODAS 2.0 has as a 12 or 36 item version. We chose the 12 item version for this study because the 12 item version has been validated in surgical patients [6] and we have previously used the 12 item WHODAS 2.0 as part of a pilot survey reporting patient satisfaction in Madagascar [20]. Additionally the 12 item version is easy to use; can be administered face-to-face or by telephone in about 5 min [13], and is publicly available [12].
WHODAS 2.0 lists 12 activities of daily living and asks individuals to rate the level of difficulty experienced for a task during the previous 30 days [12]. A five-point rating scale (none = 0, mild = 1, moderate = 2, severe = 3, extreme/cannot do = 4) is used; the scores on each activity are combined into a final score out of 60 which is then expressed as a percentage. Higher scores reflect greater disability and a score of 25% or greater is defined as disability [6].
Preoperatively, trained nurses and translators fluent in English, French, and Malagasy, administered the 12-item WHODAS 2.0 (French version) by face-to-face interview. For patients in whom French language was limited, the translators gave additional explanations in Malagasy according to WHODAS administration guidelines. The same nurses and translators telephoned patients 3 months after surgery for post-operative administration of WHODAS 2.0. Up to three separate attempts were made to reach each postoperative patient. Missing data on any survey were handled according to WHODAS manual guidelines [13]: if a single response was missing, the mean value of the remaining responses was assigned; and if more than one response was missing the WHODAS score was not calculated.
Demographic data, American Society of Anesthesiologists (ASA) physical score, duration of surgery, length of hospital stay, and in-hospital post-operative complications were collected from a separately maintained patient database. The ASA score is an international physical status classification system for patients prior to surgery [21]. ASA status is classified as I-VI (I, normal healthy patient; II, patient with mild systemic disease; III, patient with severe systemic disease; IV, patient with severe systemic disease that is a constant threat to life; V, a moribund patient who is not expected to survive without the operation; VI, a declared brain-dead patient whose organs are being removed for donor purposes). Catalogued post-operative complications were unexpected readmission, unplanned return to the OR, unexpected ICU admission, surgical site infection as defined by the US Centres for Disease Control [22], myocardial infarction; stroke, renal failure, gastrointestinal bleed, deep vein thrombosis, pneumonia, sepsis, urinary catheter associated urinary tract infection, central venous catheter associated blood stream infection, coma greater than 24 h, cardiopulmonary arrest, and death.
Hypothesis and primary outcome measure
The primary hypothesis was that surgical interventions would decrease pre-operative disability. Therefore the primary outcome measure was difference in pre and post-operative WHODAS 2.0 scores.
Statistical analysis
Statistical analysis was performed with Microsoft Excel Real Statistics. A paired t-test was used for comparison of pre and postoperative WHODAS 2.0. Two sided p-values of < 0.05 were considered significant. Mann Whitney test was used to compare non-parametric data (age, sex, ASA score, surgical duration and hospital length of stay) between patients follow-up and those lost to follow-up. Two sided p-values of < 0.05 were considered significant.