Table 1 Incidence of SIPE
References | Study design | Subjects | Sample size and description | Type of exposure | Case definition | Case ascertainment method | Incidence reported (n = SIPE cases) | Critical evaluation (see Additional file 4 for more detail) |
|---|---|---|---|---|---|---|---|---|
Smith et al. [16] | Prospective incidence study | Triathletes | 68,557 competitors in 11 triathlon races in the UK between 2011 and 2016, distances of 400 m, 750 m and 1500 m | Not reported | Absence of water aspiration, acute onset of dyspnoea, cough and/or frothy sputum, with evidence of pulmonary oedema on physical examination | Medical records of competitors presenting to medical team | 0.01% (n = 5) of triathlons raced | Conference abstract so limited detail. Only included competitors that sought medical assistance. No information on demographics. Unclear if any cases were recurrences in same individual |
Braman Eriksson et al. [15] | Prospective incidence study | Outdoor swimmers (elite and amateur) | 13,878 swimmers (6317 males, 7561 females) aged 12–70 competing in Swedish river races over 3 days in July 2016, distances of 1–3 km | Moderately cold freshwater (17 °C), unknown number of swimmers wore wetsuits | No standard definition. Examining physicians identified cases without a formal case definition. | Clinical examination of competitors presenting to medical team | Approx. 0.5% (n = 69) of races swum | Patient symptoms and clinical findings were not recorded. No information on competitors that did not seek medical attention |
Adir et al. [12] | Prospective incidence study | Military trainees (Israeli Navy) | Unknown number of males aged 18–19 in swimming trials of 2.4–3.6 km distance (average of 30–45 min duration) in 1998–2001 | Open sea of varying temperatures (19.6 °C ± 3.2), no wetsuits, supine semi-reclining position with fins | Severe shortness of breath and coughing during or after swimming in the absence of sea aspiration, and evidence of PE found on medical examination | Interview and clinical examination of swimmers presenting to medical team | 1.8% (n = 70) of swimming trials performed | Unknown total number of swimmers and time trials. Unclear number of new cases versus recurrences |
Shupak et al. [13] | Prospective incidence study | Military trainees (Israeli Navy) | 35 males aged 18–19 performing 5 swimming trials (2.4–3.6 km) over 2 months (mid-Jan to mid-Mar). Trials were ≥ 1 week apart | Moderately cold open sea, (16–18 °C), diving jackets, supine position with fins | When, in the absence of prior seawater aspiration, the swimmer reported shortness of breath accompanied by coughing | Post-swim questionnaire completed by all trainees | 16.6% of 175 swimming trials: 8 severe cases (4.6%), 21 mild cases (12%) 60% of swimmers (n = 21) had 29 episodes of SIPE | Sample size small. Study only lasted 2 months |
Weiler-Ravell et al. [14] | Prospective incidence study | Military trainees (Israeli Navy) | 30 males aged 18–19 performing a single 2.4 km swimming trial | Warm open sea (23 °C), no wetsuit, supine with fins, over- hydration (trainees drank approx. 5 l of water prior to swimming) | Dyspnoea and haemoptysis | Clinical examination of trainees presenting to medical team | 26.7% (n = 8) of swimmers in one trial | Only one swimming trial. No clear case definition |