Unintentional drowning in Finland 1970–2000: a population-based study

Philippe Lunetta1, Gordon S Smith2, Antti Penttilä1 and Antti Sajantila1

1 Department of Forensic Medicine, PO Box 40 (Kytösuontie 11), University of Helsinki, 00300 Helsinki, Finland
2 Liberty Mutual Research Institute for Safety, 71 Frankland Road, Hopkinton, Massachusetts 01748 USA. E-mail: philippe.lunetta{at}helsinki.fi


    Abstract
 Top
 Abstract
 Material and Methods
 Results
 Discussion
 References
 
Background While standard data on drowning reported by the World Health Organization (WHO) fails to provide a reliable picture of the burden of drowning in Finland, they suggest that the rates are much higher than those of other industrialized countries.

Aim To determine the true burden of drowning in Finland and factors related to its high rates.

Design Descriptive, retrospective, population-based analysis of all deaths by drowning, among residents of all ages.

Setting Finland, 1970–2000.

Material and Methods Mortality and population data furnished by Statistics Finland (SF) were used to determine age- and sex-specific drowning mortality rates using both nature- and cause-of-injury codes. Individual-level data from the death certificates were analysed and cross-linked to a nationwide postmortem toxicology database.

Results From 1970 to 2000, 9279 unintentional drownings occurred (mean: 299.3/year SD 84.3, rate 6.1/100 000/year; M:F ratio = 8.6:1), accounting for 11.7% of all unintentional injury deaths. Drowning rates overall have decreased from 9.9/100 000/year in 1970–1972, to 4.5 in 1998–2000 (–2.7%/year; 95% CL: –3.0; –2.5). The most frequent activities related to drowning included boating (29.8%), falling (26.1%), swimming (25.0%), and activities on ice (12.4%). In non-boating-related drownings, 74.5% of males and 67.4% of females tested had a blood alcohol concentration (BAC) ≥50 mg/dl, while in boating-related drownings, the respective values were 78.1% and 71.4%.

Conclusions WHO statistics underestimate the true burden of drowning in Finland by up to 40–50%. Drowning rates and alcohol involvement in drowning are much higher than in other comparable developed countries. Broad-based countermeasures to reduce alcohol use in water activities are needed as part of any strategy to reduce drowning rates.


Keywords Drowning, immersion, surveillance, alcohol, forensic autopsy, Finland

Accepted 9 March 2004

Drowning is an important cause of unintentional injury deaths and a major contributor to premature mortality in many countries.1–3 Almost 500 000 people are annually estimated to die around the world as a result of drowning, the second leading cause of injury death after traffic accidents.2,4 Official statistics are, however, known to underestimate the true burden of drowning and recent studies in high-income countries (US, Australia, New Zealand) have shown the importance of considering all drownings (e.g. boating, transport) in obtaining a complete profile of drowning mortality.5–8

Located in northern Europe, Finland (population: 5.3 million) with 1100 km of coastline, 9650 km of inland waterways, and more than 188 000 lakes,9 is a water-oriented society with a high mortality in aquatic settings.10 Despite a progressive decrease in drowning rates, our preliminary analyses using official statistics revealed that Finnish drowning rates at the end of the 1990s (4.9/100 000) were still significantly higher than those of other developed countries.11–16 However, neither the reported statistics nor our earlier paper focusing on boating deaths provided a comprehensive picture of all unintentional drownings in Finland.10

In this population-based study, we examined the potential reasons for the apparently high drowning rates relative to those of other industrialized countries, including the time trends and demographic features of unintentional drownings among Finnish residents of all ages, from 1970 to 2000. Because more detailed information from coded data in vital statistics is unavailable, we also reviewed original death certificates from 1998 to 2000 to obtain more information on the circumstances of all unintentional drownings and on the drowning victims themselves.


    Material and Methods
 Top
 Abstract
 Material and Methods
 Results
 Discussion
 References
 
Design and setting
We conducted a descriptive, retrospective, population-based analysis of aggregate- and individual-level data for unintentional drowning among Finnish residents of all ages, from 1970 through 2000.

Data collection and analysis
Mortality and population data furnished by Statistics Finland (SF), for 1970–2000, were used to determine drowning mortality rates by sex and age groups based on the resident population. From 1987 to 2000, SF collected data on whether the certifying physician considered alcohol intoxication a contributing cause of death (generally when blood alcohol concentration [BAC] is ≥50 mg/dl).17

Individual-level data tabulated by SF for all unintentional drownings occurring from 1 January 1970 to 31 December 2000 were selected for analysis by use of the International Classification of Disease, 8th, 9th, and 10th Revisions (ICD-8, ICD-9, ICD-10) ‘nature of injury’ and ‘external cause of injury’ codes (N and E codes, respectively) for drowning.*,** The variables were gender, age, dates of birth and death, province of death, and factors contributing to death. In addition, we examined the free-text and other fields on all death certificates from drownings occurring from 1 January 1998 to 31 December 2000 for information on site and pre-drowning activities.{dagger}

To obtain BAC values and other toxicology results, individual level-data from 1998 to 2000 were linked, using each victim's demographic variables, with the database of the Laboratory of Toxicology, Department of Forensic Medicine, University of Helsinki. This laboratory carries out by statute most of the alcohol analyses and all other toxicology for the entire country.18,19 BAC values missing from this database were obtained from forensic pathologists in charge of the respective cases and from clinical records of victims who died in hospital.

Statistical methods
The Poisson regression model (EGRET, 1999) was used to analyse time trends. The 95% CI were calculated assuming a Poisson distribution. For comparison of proportion Pearson's {chi}2 test for independence (StatXact-5, 2001) was used.


    Results
 Top
 Abstract
 Material and Methods
 Results
 Discussion
 References
 
From 1970 to 2000, there were 9279 unintentional drownings in Finland (6.1/100 000/year; mean: 299.3/year SD 84.3), accounting for 11.7% of all unintentional injury deaths. Of these drownings, 56.5% (n = 5244) were non-boating-related, 37.1% (n = 3443) boating-related, 5.7% (n = 529) land-traffic-related, and 0.7% (n = 63) related to other external causes (Table 1). The distribution of drowning in the six provinces of Finland ranged from a high of 9.3/100 000 in the lake-rich eastern province bordering Russia with no access to the sea, to a low of 5.3/100 000 in the western coastal province.


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Table 1 Drowning 1970–2000. Total number, rates, and time trends, by manner

 
Age and gender distribution
Boating-related drowning rates peaked among 50–54 year olds, while the distribution of non-boating drownings was bimodal, with a first peak among 0–4 year olds and a second among 60–64 year olds (Figure 1). Children 0–14 years old accounted for 8.7% of cases. The male:female ratio was 8.6:1 for all drownings, 21.5 for boating-related drownings, 9.3 for both non-boating and land traffic-related drownings, and 4.4 for other unintentional drownings.



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Figure 1 Unintentional drowning 1970–2000: age-specific rates, non-boating and boating-related drownings

 
Monthly distribution
Most (65.2%) boating- and non-boating-related drownings occurred during the warmer months (May–August) with a peak in June and July (Figure 2). The other drownings, including mostly those resulting from traffic crashes, occurred more frequently in spring and autumn.



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Figure 2 Unintentional drowning 1970–2000: monthly distribution, non-boating and boating-related drowning

*The line shows the average air temperature in Helsinki, source: Finnish Meteorological Institute.

 
Drowning and alcohol
During 1987–2000, alcohol was a contributing factor to death in 63.9% of boating-related drownings (annual range: 54.4–76.7%) and 51.6% of other drownings (annual range: 41.3–58.5%) among victims of all ages.

Time trends: 1970–2000
General trends
Overall unintentional drowning rates have decreased almost 3% annually during 1970–2000. This decrease was greatest for boating-related drownings (–3.36% annually), while the decrease in non-boating drowning (–2.47%) and land-traffic drowning (–1.58%) was less pronounced (Table 1, Figure 3). The decline in drowning deaths was over 10 times as great as for all unintentional injuries, which also declined significantly during the same period, but less markedly (–0.23%; 95% CI: –0.31, –0.16).



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Figure 3 Unintentional drowning 1970–2000: time-trends of boating and non-boating related drowning

*Trend line: two-period moving average.

 
Trends by age groups and genders
Overall drowning rates decreased similarly in males (–2.86%/year; 95% CI: –3.1, –2.6) and females (–2.70%/year; 95% CI: –2.0, –1.3), while boating-related drowning declined more markedly in both sexes (–3.9% versus –5.4%, male versus female) than non-boating drowning (–2.6% versus –1.8%). The boating- and non-boating-related drowning rates declined significantly in most age groups, with the largest decrease in the younger age groups (0–34 years); non-boating drowning showed, however, an upward trend for 55–64 year olds (Tables 2a, 2b).


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Table 2a Boating drowning 1971–2000. Time trends in drowning rates, by age groupsa

 

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Table 2b Non boating-drowning 1971–2000. Time trends in drowning rates, by age groups

 
Trends by months
Overall unintentional drowning rates decreased significantly during every month except February, September, and December. The highest decrease occurred in May (–3.94%/year; 95% CI: –4.98, –2.90).

Drowning and alcohol
During 1987–2000, alcohol-positive boating-related drownings among victims of all ages decreased significantly (–5.77%/year; 95% CI: –7.54, –4.96) but non-boating drowning saw no significant changes (–0.23%/year; 95% CI: –1.68, 1.24).

In depth study: 1998–2000
During 1998–2000, there were 704 (234.7/year; rate 4.5/100 000/year; M:F = 6.4) unintentional drownings classified with the ICD-10 codes for drowning; 450 (63.9%; 2.9/100 000/year) were non-boating-related, 204 (29%; 1.3/100 000/year) were boating-related, and 50 (7.1%; 0.3/100 000/year) were classified with an ‘E code’ other than for drowning. Among the latter group were 45 (6.4%; 0.3/100 000) land traffic-related drownings. In 687 cases (97.6%) the diagnosis was based on a medico-legal autopsy, in 13 (1.8%) cases on clinical data, and in the remaining 4 (0.6%) on a certificate of death issued abroad. In only 19 cases (2.7%), did death from complications occur in a hospital >24 hours after the submersion episode. Ten victims (1.4%) were foreign residents in Finland, and 11 (1.6%) cases involved Finns who drowned abroad.

Distribution by site and activities
Most fatalities (97.3%) occurred at the scene, and only 2.7% during hospital care. The majority of cases occurred in fresh water (82.1%), mainly in lakes (43.9%), with only 17.9% occurring at sea (Table 3). More than 80% of the cases were related to boating, falling into the water, or swimming; 12.4% were connected with activities on ice; and the remaining cases resulted from traffic accidents, bathing, or diving (Table 4). The main location for boating (n = 210), falling (n = 184), and swimming (n = 176) drownings was a lake (60.8%, 47.2%, and 23.9%, respectively). Only 8% of swimming-related drownings occurred at sea. Activities on ice were responsible for 12.4% (n = 87) of drownings; 34.5% of which involved walking, 23.0% driving a snowmobile, 16.1% operating a kick-sled, 13.8% skiing or skating, and 4.6% driving a car or moped. More than half (55.2%) of these cases occurred on a lake.


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Table 3 Unintentional drowning 1998–2000: distribution by site

 

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Table 4 Unintentional drowning 1998–2000: distribution by associated activity

 
Swimming-related drownings had a clear peak in June and July, while boating drownings were more evenly distributed during summer and autumn, as were also the fall-related drownings. Drownings related to activities on ice peaked in December and April.

Association with alcohol
BAC analysis was performed on 84.5% of the victims. Of 704 drowning victims of all ages, 405 (57.5%) had a BAC ≥50 mg/dl, 386 (54.8%) ≥100 mg/dl, and 133 (18.9%) ≥250 mg/dl. Among 15–64 year olds not dying in hospital, the testing rate was 92.2%. Among 15–64 year old victims tested for alcohol, the percentage of alcohol-involved cases (BAC ≥50 mg/dl) was 75.0% (Table 5). Among those >65 this percentage fell to 46.3%, while among those <15 there was only one alcohol-positive case (6.7%, male) (Table 6). In non-boating drownings, 74.5% of the males and 67.4% of the females tested for alcohol had a BAC ≥50 mg/dl, but in boating-related drownings, the respective values were 78.1% and 71.4%. Overall, the strongest association was observed in fall-related drownings (82.8%), followed by those related to swimming and boating (78.9% and 77.8%, respectively) (Table 7). Most of the alcohol-positive cases occurred during the warm season (81.0%) in natural bodies of water, especially ponds (86.4%), rivers (83.1%), lakes (75.9%), and the sea (74.5%) (Tables 8, 9). Although based on only eight drownings, the highest proportion of alcohol-positive drowning was found in bathtub drowning (87.5%) (Table 8).


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Table 5 Unintentional drowning 1998–2000: Blood alcohol concentration (BAC) (mg/dl) among victims 15–64 years old tested for alcohol (n = 472)

 

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Table 6 Alcohol-related unintentional drowning (blood alcohol concentration [BAC] ≥50 mg/dl), by age groups (1998–2000)

 

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Table 7 Alcohol-related unintentional drowning (blood alcohol concentration [BAC] ≥50 mg/dl) among victims 15–64 years old (n = 524), by activity (1998–2000)

 

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Table 8 Alcohol-related unintentional drowning (blood alcohol concentration [BAC] ≥ 50 mg/dl) among victims 15–64 years old (n = 524), by site (1998–2000)

 

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Table 9 Alcohol-related unintentional drowning (blood alcohol concentration [BAC] ≥50 mg/dl) in victims 15–64 years old (n = 524), by season (1998–2000)

 
Association with drugs
Screening for drugs other than alcohol was performed on 252 (48.0%) of the 525 victims 15–64 years old. No illegal drugs were found in the victims; 187 (74.2%) tested negative for drugs while 65 (25.8%) tested positive for one or more therapeutic drugs. In 52 (20.6%) cases, tests detected a psychotropic drug, and 65.4% of these cases showed BAC >50 mg/dl. Bath-related drownings were tested for drugs in four of eight cases, two of which revealed traces of psychotropic drugs.

Contributing factors
The death certificates reported no contributing cause of death in 76 (10.8%) cases, a single contribution in 495 cases, 2 in 119 cases, and 3 in 14 cases. The contributing factors were alcohol in 375 cases, a medical condition in 165 cases, trauma and other external causes in 25 cases, and medication use in 16 cases.

The most frequent ‘natural’ contributing factor was cardio-circulatory disease (n = 116). The certifying physician considered epilepsy a contributing factor to death in 8 (1.1% of all drownings) of the 15 victims with a history of seizures, and in 2 cases deemed it the underlying cause of death. Only one drowning associated with an epileptic seizure was witnessed. Among contributing factors due to external causes were 11 incidents with head trauma, 10 involving hypothermia, 2 cases of tibia fractures, and one case each for air embolism and food aspiration.


    Discussion
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 Abstract
 Material and Methods
 Results
 Discussion
 References
 
Drowning has been a public health concern in Finland since the first cases were reported in the church-based death registries during the 1600s.20 From 1866 to 1890, a total of 14 396 unintentional drownings were reported (51% of all unintentional injury deaths), a rate of 28.7/100 000.21 Since then, drowning rates have progressively decreased to 8.9/100 000 by the end of the 1960s.22 Our study shows that the overall rates have continued to fall during the last three decades, from 9.9 in 1970 to an all-time low of 4.4 in 1998–2000, a 2.7% annual decline.

Despite these declines, Finland continues to have one of the highest drowning rates in the developed world. It is the fourth leading cause of unintentional injury death among all age groups, after falls, poisoning, and traffic injuries,11 and accounted for 8.5% of all unintentional injury death during 1998–2000. This percentage is consistently lower, for instance, in the US and Canada (4.3% and 5.8%, respectively).12–14 While Finland's rates of drownings in younger children are similar to or even slightly lower than in other high-income countries, drowning rates in adults are much higher, especially among older males. Alcohol involvement in this group was very high (75% of 15–64 year olds tested for alcohol had a BAC ≥50 mg/dl) compared with other developed countries.

There are two main levels of data on drowning for international comparisons.6,8 Standard WHO data are available for many countries worldwide but furnish no reliable figures on the global burden of drowning because most developing countries collect no or inadequate data on water-related mortality. Furthermore, WHO data do not include drownings from natural disasters (e.g. flood), which, in low-income countries, are major contributors to drowning rates. In addition, WHO reports neither boating-related drownings (which account for up to 30% of drownings in Canada), nor land-transport drownings (which account for 11% of drownings in New Zealand).5,14 More comprehensive data on drowning comes from in-depth studies performed in some high-income countries, especially the US, Canada, Australia, and New Zealand.8 In Europe, nationwide studies were performed during the 1990s only in Denmark;23,24 in Finland there was one national study but it was limited to boating-related drowning.10

Finnish rates of both boating- and non-boating-related drowning are higher than those in developed countries where in-depth studies have been performed.7,12–14,23,25 The overall rates in Finland are approximately 2–3 times higher than in the US, Canada, and Australia.6,12,14,25 Comparison with European Union (EU) and Nordic countries is possible only for non-boating drownings based on narrowly defined WHO data. Finnish non-boating drowning rates are the highest among the Nordic countries, rank second among EU countries after Greece, and surpass the EU average by 2–3 times.26

Boating- and land traffic-related drownings, not included in the WHO data, account for some 30–40% of additional cases.10,11,15 Furthermore, because of its high boating-related drowning rates, Finland probably has the highest overall drowning rates in the EU. Overall, during 1990–2000, the WHO underestimated Finnish drowning rates by 40% (min. 28% in 1999; max. 51% in 1993). Finnish drowning rates remain, however, below those reported by the WHO for neighbouring Baltic countries (e.g. Latvia: 9.9/100 000) and Russia (11.1/100 000).26

The Finnish unintentional drowning rates are a conservative estimate since the data obtained does not include those unintentional drownings which may have been classified as ‘undetermined drowning’.27 The prevalence of adult male victims, especially in boating-related drownings, is more pronounced in Finland than in other industrialized countries.1214,23,25 For adult males, the overall rates are up to 3–4 times as high as those in the US and Canada,12,14 which has been related to possible differences in swimming skills, higher exposure frequency and risk-taking behaviour as well as heavier alcohol use in water settings.28

The relation between drowning and alcohol has been documented in different countries and various settings,10,14,25,28–35 even though the proportion of victims tested in different studies and the different criteria used to define alcohol-positive drowning represent important issues for comparability of data. In Finland, the association between alcohol and drowning is, especially among adult males, higher than in other countries.14,23,29–33 Most studies report between 25% and 50% of drownings as alcohol-related. In the US, for instance, alcohol was involved in 31% of all 701 recreational boating fatalities occurring in 2000;13 in a Maryland and North Carolina study of 221 recreational boating fatalities from 1990 to 1998, 36% had a BAC >50 mg/dl.29 In Canada in 1999, 32% of the 122 victims of boating-related drowning and 53% of the 40 victims of swimming-related drowning had a BAC >80 mg/dl.14 In Finland alcohol is involved in 63.8% of non-boating- and 77.8% of boating-related drowning victims 15–64 years old. We presented the result of alcohol-involved drowning, in our study, as the percentage of the cases tested, since those cases not tested cannot be assumed to be BAC negative. Indeed, although medical examiners in Finland may occasionally not determine BAC if they expect the result to be negative, when we reviewed the cases not tested for alcohol, they appeared likely to have a distribution of BAC values similar to those tested. We considered alcohol to be involved in cases with a BAC >50 mg/dl, a value that only can occasionally be attributed solely to endogenous alcohol production.36 Moreover, when considering the cases with a BAC >100 mg/dl, the percentage of alcohol-positive dropped ‘only’ from 68.1% to 64.9% of all unintentional drowning tested.

The role of risk factors other than alcohol is more difficult to assess. In our study, 2% of drowning victims had a history of seizures, but this was mentioned as a contributing factor in approximately half the cases and deemed the underlying cause of death in 0.3% of the cases. The proportion of drownings with epilepsy as an underlying cause of death in other countries is higher, and ranges from 0.7% (US) to 4.8% (England and Wales).6 These differences may well represent differing attitudes of the certifying physicians towards the causal attribution of epilepsy and application of the ICD coding rules, especially in unwitnessed cases. On the contrary, according to ICD-10 rules, other natural diseases that lead to drowning by causing victims to fall into water or by incapacitating them while in the water are considered contributing factors of death, not underlying causes.

Childhood drowning rates in Finland compare favourably with international rates:37 they accounted for 8.7% of all unintentional drownings during 1970–2000, which decreased to 5.2% for 1998–2000. Drowning rates among children aged 0–14 years are lower than those reported in Canada, the US, the UK, Australia, and Denmark,12–14,24,25,38–40 especially among 0–4 year olds. In older childhood groups the rates are slightly higher than in other industrialized countries; for instance, at the end of the 1990s, the non-boating drowning rate in Finland among 5–9 year olds was about 2.1/100 000, while in the US, the corresponding values have been under 2.0/100 000 since the 1980s.38,39 In Finland, children drown mainly in natural bodies of water, while drowning in swimming pools, which accounts for many childhood drownings in other high-income countries,39,41 is very rare. This is likely due in part to the low number of residential swimming pools, reflecting the short swimming season. Drowning rates in adolescents and young adults in Finland are also similar to those in countries such as the US,33,38,40 but in contrast do not show the peak in rates that are seen in many other countries.

In Finland, the percentage of drownings due to boating (28.9% 1998–2000) is similar to that in Denmark and New Zealand,7,24 but higher than in the US, Canada, and Australia.12–14,25,42 High alcohol use and the short survival time in water due to hypothermia and alcohol effects, together with the low number of witnesses,43 which would impede prompt rescue, may account for the high boating-related fatality rates in Finland. The typical victim is a middle-aged male under the influence of alcohol operating a small motorboat for leisure on a lake during the summer.

Most of the remaining drownings occur either as a result of a fall into ice-free water (26%) or swimming (25%). The proportion of fall- and swimming-related drownings in different countries varies. For instance, the proportion of fall-related drowning ranges from 12% of all drowning in New Zealand to 20% in Canada, while that of swimming-related drownings ranges from <11% in Denmark to 15% of all drownings in Canada.7,14,24 In Finland, the typical victim of a fall-related drowning is a man in his late 40s under the influence of alcohol who falls into a lake. Less than half of these cases occur during the warm season. Swimming-related drownings also occur in lakes among men of about the same age, who are usually under the influence of alcohol. More than 80%, however, occur during the warm season, which lasts until August, when water activities diminish with the end of the summer holiday and the children's return to school.

Ice-related drownings usually involve walking or driving a snowmobile on ice and represent 12.4% of all Finnish drownings. This is higher than that of Canada but comparable to the US state of Minnesota.14,44 Spring, especially April, is a high-risk period because the ice covering inland and coastal waters starts to melt and people spend more time outside. During the 1990s in Finland, drowning was the cause of death in 40.6% of all fatal snowmobile accidents,45 while in northern Sweden it accounted for 38%.46 In both Finland and Sweden, alcohol was a contributing factor in about 60% of these cases. Land transport drowning rates (motor vehicles in the water) account for about 3.1% of all drowning in Finland, a percentage lower than in Canada, Australia, Denmark, or New Zealand.5,7,14,15,23

Drowning in the bathtub is rather rare in Finland (1.8% of all drownings) compared with countries such as Canada and Australia, where it accounts for as much as 5–7% of all drownings.14,42 In our study, all victims were adult, mostly elderly, with a M:F ratio lower than in other settings. A BAC of ≥50 mg/dl existed in more than half of these cases, and only one victim had a history of seizures. The low drowning rates in bathtubs reflect the Finn's habit of using saunas and showers more frequently than baths. Childhood drowning in or near the home has decreased significantly since the 1950s,47 as tap water in domestic settings became more available, showers more popular, and the exposure of children to bodies of water near to or at home began to decrease. From 1998 to 2000 there was only one domestic child drowning, involving a 3 year old who drowned in a plastic tub.

As in other industrialized countries, recent decades have seen a decline in drowning rates in Finland, despite improved diagnosis and recording of deaths.48,49 While one reason for overall declines in injury rates in many countries has been improved trauma care,50 it appears little has changed in case-fatality drowning rates, which suggests that this decline is due to decreased incidence rather than improved survival following submersion.48 This trend has been attributed to the effectiveness of preventive measures, decreased exposure to risk, and safer behaviour in aquatic settings, and migration of populations away from bodies of water, safer boats, especially improved floatation, and possibly to a decrease in the use of alcohol in water settings.

An earlier commentary suggests that the decline in drowning may not necessarily be due only to improved water safety practices but in part to decreased exposure, at least in the US.49 In Finland, the study period overlapped with a period of significant economic growth with potentially increased exposure due to the increasing number of second homes in recreational water settings,9 and boat and snowmobile ownership. Despite this the downward trends have been rather homogeneous, observable among both genders, and in most age groups, in boating- and non-boating related drownings, and in every province. The time trends were also relatively linear, with no specific patterns even after the introduction of the revised ICD classifications in 1987 (ICD-9) and 1996 (ICD-10), indicating that it was unlikely due to coding changes. These favourable trends suggest the potential benefits of increased public awareness of danger related to aquatic activities, of swimming education among the young,* and the introduction of a legal BAC limit for boat operators (150 mg/dl in 1976, further reduced to 100 mg/dl in 1994).10 The larger decline seen for boating drownings in children may also be due to their increased use of life jackets. Drowning rates among the older age group, however, remained stable which caused a progressive shift toward the older age group of the second peak of the bimodal age distribution. The selective decrease in drowning rates particularly in late adolescent, young, and middle-aged adults could be due to the selective efficiency of prevention in these age groups. Alternatively similar declines in drowning may be explained by reduced exposure to hazardous bodies of water and more time spent in sedentary activities such as playing video games or watching TV, or in more structured and supervised recreational activities.49 Follow-up studies however are needed to substantiate this hypothesis.

The quality of data available on drowning in Finland is high,15,16 with more than 97% of cases having undergone a full medico-legal autopsy. Because both nature- and cause-of-injury codes are recorded, it was possible to identify all drownings, including those not reported in WHO statistics, such as drowning related to motor vehicle or snowmobile accidents. WHO statistics fail to report such cases as drowning. The development of a more comprehensive surveillance system such as that in New Zealand and Canada, however, would provide much more useful information for studying risk factors and developing and monitoring the effectiveness of prevention strategies.

The heterogeneous nature of drowning in Finland indicates that a diversified approach is required to set appropriate preventive countermeasures. Swimming education programs are a priority of the Finnish Association for Swimming Instruction and Life Saving (SUH).* The relation between swimming ability and drowning is, however, controversial, since improved swimming proficiency may result in a greater exposure to risk and must be linked to the promotion of safe behaviours in water settings.52 It appears that if we are to lower Finland's drowning rates to levels comparable to those of other EU countries and the developed world, we must further address the major issue of alcohol use in aquatic settings. Finland has had much success in reducing alcohol involvement in motor vehicle fatalities (53), but the hazards of drinking on or near the water still seem overlooked, despite the risk being, if anything, higher than on the highway.29


KEY MESSAGES

  • Drowning rates in Finland continue to be the highest among EU countries and are 2–3 times higher than in the US, Canada, and Australia despite declining dramatically from 9.9/100 000 per year for 1970–1972, to 4.4 for 1998–2000.
  • From 1970 to 2000, 9279 unintentional drownings occurred in Finland, accounting for 11.7% of all unintentional injury deaths.
  • WHO statistics underestimate the true burden of drowning in Finland by up to 40 to 50%.
  • Alcohol is an important risk factor for drownings in Finland; 75% of 15–64 year old drowning victims tested for alcohol had a blood alcohol concentration ≥50 mg/dl.
  • Finnish childhood drowning rates compare favourably with international rates as do rates in adolescents. These rates have declined from 1970 to 2000 by 5–7% annually.
  • The peak drowning rates are in the older age groups, which have declined much less than in younger people, and in fact have increased among those aged 55–64 years.

 


    Acknowledgments
 
The authors wish to acknowledge the contributions of the International Collaborative Effort (ICE) on Injury Statistics to this research. The ICE is sponsored by the National Center for Health Statistics, US Centers for Disease Control and Prevention with funding from the National Institute of Child Health and Development, National Institutes of Health.


    Notes
 
* N codes: 1970–1986 (ICD-8) and 1987–1995 (ICD-9): 994.1; 1996–2000 (ICD-10): T75.1. Back

** E-codes: 1970–1986 (ICD-8) and 1987–1995 (ICD-9): E910 (non-boating drowning), E830, E832 (boating-related drowning); 1997–2000 (ICD-10): W65–74 (non-boating drowning), V90, V92 (boating-related drowning). Back

{dagger} The procedures were approved by the local human subject ethical committee. Back

* The Finnish Association for Swimming Instruction and Life Saving (SUH) is an educational and informational organization established in 1956 which aims at improving the swimming skills of Finns and at reducing the number of fatal drowning accidents with the aid of education and swimming instruction.51 The SUH, together with the Finnish Maritime Administration, Ministry of the Interior, Ministry of Transport and Communication, Ministry of Social Affairs and Health, Finnish Centre for Health Promotion, has recently promoted a Safety in Water programme, which emphasizes four main themes: the risk of alcohol use in water setting, the use of life jackets on the water, the importance of good swimming skills, and safety on ice. This campaign is carried out as a national media campaign (TV, cinema, radio, and printed advertisements) and targets especially men of the most active age. It is supported by the "Wisely in the Water" tour, travelling around more than 40 localities during the summer (covering rescue operations, use of safety equipment, resuscitation). Back


    References
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 Abstract
 Material and Methods
 Results
 Discussion
 References
 
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