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Another gender data gap: female drowning in Aotearoa, New Zealand
  1. Karen Richardson1,
  2. Amy E Peden2,3
  1. 1 Water Safety New Zealand, Wellington, New Zealand
  2. 2 School of Population Health, Faculty of Medicine, UNSW Sydney, Sydney, New South Wales, Australia
  3. 3 Royal Life Saving Society - Australia, Broadway, NSW, Australia
  1. Correspondence to Karen Richardson, Water Safety New Zealand, Wellington 6011, New Zealand; karen{at}


Introduction A gender gap is present in drowning research and prevention interventions, resulting in an inequitable focus on males. This study aimed to address the gender data gap, exploring female drowning in Aotearoa, New Zealand.

Methods National data on female fatal and non-fatal drowning requiring hospitalisation between 2003 and 2019 were sourced from DrownBase, Water Safety New Zealand’s drowning database. Univariate and χ2 analyses were conducted for fatal and hospitalisation data. Crude rates were calculated and used to explore temporal trends and RR by age groups and ethnicity for fatal and non-fatal drowning. Ratios for drowning-related hospitalisations and Accident Compensation Corporation (ACC) claims to drowning deaths were also calculated.

Results From 2003 to 2019, a total of 1087 female drowning fatalities and non-fatal (76.0%) drowning incidents requiring hospitalisation occurred. Linear trends indicate hospitalisations increased (y=0.0766x+1.4271; R2=0.4438), while fatal drowning decreased (y=−0.0101x+0.7671; R2=0.1011). The highest fatal (1.60) and non-fatal (8.22) drowning rates were seen among children aged 0–4 years. For every one female drowning fatality, there are 3.46 hospital admissions and 675.55 ACC claims.

Discussion Female drowning represents a significant burden on the health system and the community in New Zealand. Further investment in interventions targeting females about their own risky behaviours around water (not only children in their care) is suggested, including interventions focused on hazardous conditions and alcohol consumption.

Conclusion For decades, the focus of drowning prevention among adolescents and adults has been on males. However, efforts must be broadened to prevent any further increase in drowning-related incidents among females in Aotearoa, New Zealand.

  • gender
  • policy
  • descriptive epidemiology
  • drowning
  • public health
  • alcohol

Data availability statement

Data may be requested and a data access agreement entered into if deemed to be a suitable project. Please contact

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Equity is a vital component of public health; however, gender, like ethnicity,1 2 is one area where effort has been inequitably distributed to the disadvantage of those excluded.3–5 The gender gap is an example of androcentrism, the propensity to centre society around men and men’s needs, priorities and values, relegating women to the periphery.6 There is much evidence for sex differences at all levels of biological organisation; therefore, to predominately study males and apply the results to females is unhelpful.7

This gender gap exists in both our knowledge and in the data that knowledge is based on. A lack of sex disaggregated data affects our ability to give women sound health and safety advice.8 It is well documented that females have long been left out of clinical medical trials,9 resulting in a negative impact on women’s health.

The gender data gap is a not a new phenomenon; most of recorded history is one big gender data gap. With the world becoming increasingly reliant on ‘big data’,10 there is an opportunity to redress this imbalance. However, although the Sustainable Development Goals11 includes a standalone goal on gender equality and empowerment of women and girls, as well as several gender sensitive indicators within other goals, progress is slow.12

The availability of official data on the structural aspects of the lives of women and girls is insufficient, and data are rarely disaggregated by sex, hampering both the reach of any analysis and makes gender inequality invisible.13 Recent initiatives from the United Nations such as the Evidence for Data and Gender Equality project and the Data 2x organisation,14 along with Stanford University’s Gendered Innovations programme15 are all dedicated to raising awareness and improving quality, availability and use of gender data.8

Drowning is one of many injury examples where males have been the focus of research and interventions focused on prevention.16–18 Although females currently account for 30% of worldwide drowning incidents, they have, to date, received very little attention in regard to research,19 with the issue often discussed as a topic secondary to male drowning. There is a need for an examination of the pre-event and postevent circumstances of female drowning incidents to be undertaken in order to enhance the meagre evidence base.

Although the male unintentional drowning rate is higher than females, female unintentional drowning incidents in New Zealand appear to be rising.20 Female fatal drowning increased by 20% in 2018 and female hospitalisations equalled male hospitalisations in the 15–24 year age group, the first-time females have made up more than 20% of the gender ratio of hospitalisations.19 In total, female hospitalisations were up 90% on 2017.19 This increase is of concern and warrants further investigation. As such, this study aimed to examine fatal and non-fatal drowning events to gain a clearer picture of what factors are impacting on female drowning to inform future research and prevention efforts.


This total population study applies a gendered lens21 to the analysis of unintentional fatal and non-fatal female drowning in New Zealand to determine contributing factors.

Data sources

Female fatal and non-fatal drowning data from 2003 to 2019 were retrieved from Water Safety New Zealand’s (WSNZ) drowning database, DrownBase.22 DrownBase is the national database that tracks all drownings within New Zealand, both fatal (from 1980) and non-fatal drowning resulting in a hospital stay of 24 hours or longer (from 2003). Data in Drownbase were sourced from New Zealand Police, the Coronial Services of the Ministry of Justice and the New Zealand Health Information Service (NZHIS).22

Non-fatal drowning hospitalisations were defined as admission to hospital for a stay of 24 hours or longer. Data were provided by the Ministry of Health NZHIS and include all hospitals in NZ. Only those incidents that have been identified to be a drowning-related event were sent to WSNZ and subsequently recorded in DrownBase.

Accident Compensation Corporation (ACC) data include all new claims lodged for drowning-related accidents and associated medical care. The ACC is the New Zealand crown entity responsible for administering the country’s no-fault accidental injury compensation scheme. The information WSNZ receives is largely reliant on the information claimants provide when the ACC45 (ACC claim form) is completed. This research includes all claims defined as drowning based on free text where the word DROWN appeared or claims coded with contact=drowning or where the claim’s readcode was ‘Drown’ or ‘Submersion’.

Data classification and coding

The classification and coding of drowning data in New Zealand has been previously reported in detail23; however, in brief, WSNZ organises all unintentional (deemed preventable in the WSNZ system) drowning fatality data into eight activities: immersion incident (includes accidental immersion, that is, no intention of being in the water, flood/civil emergency and rescuing others); powered boat; sailing; non-powered boat; water sport/recreation (includes swimming, boogie boarding, tubing/canyoning, diving/jumping, board riding and water skiing); underwater (includes scuba diving, snorkelling and free diving); land-based fishing; and occupational related (commercial fishing). Non-preventable drowning fatalities in the WSNZ data are those arising from a road or air vehicle incident, homicide, suicide or of unknown origin. Non-preventable drowning fatalities are collated in DrownBase; however, this study focuses on unintentional drowning only.

Drowning locations were coded into eight categories: beaches; domestic environments (eg, bathtubs, buckets and toilets); home pools; inland still waters; offshore; public pools; rivers; and tidal waters. Drownings are also coded by ethnicity within the following categories: NZ European; Māori; Pacific Peoples; Asian; and ‘Other’ (eg, Australian, English and South African).

Alcohol involvement was recorded if the police and/or coroner’s report states that alcohol was involved and was a contributing factor to the event. Drugs are recorded as being involved if drugs taken were contributory to death (this includes both prescription medications and illicit drugs). Hazardous conditions were identified as being contributory to the drowning if official reports (police and coroners reports) identified such conditions (ie, rips, strong currents, high winds, large waves and darkness) as being present during the fatal drowning incident.


Univariate and χ2 analysis were undertaken to explore variance in female fatal drowning and drowning-related hospitalisations by age group and ethnicity. As up to eight variables were explored in the drowning location category, a modified Bonferonni correction24 was applied throughout the χ2 analysis deeming statistical significance p=0.006. Crude fatal drowning and hospitalisation rates per 100 000 female population were calculated using national population data from Stats NZ for December of each year by age group.25 Population estimates by ethnicity are available for census years25; therefore, a 17-year average of the deaths were used with a 3-year average (2006, 2013 and 2018) of the population to calculate rates by ethnicity. Linear trends in rates were calculated using Excel. RR with a 95% CI was calculated using the 65+ years age group and females of Asian ethnicity as the control groups.

Fatal and hospital-related drowning were compared by age group, ethnicity and season. Additional variables were available for analysis for fatal drownings only, such as drowning location, activity, drug and/or alcohol involvement and hazardous conditions. Due to data availability, the calculation of ratios of fatal drowning to drowning-related hospitalisations and ACC claims is conducted overall and by age group for the period 2015–2017 only.


Between 2003 and 2019 (a period of 17 years), there were a total of 1087 fatal and non-fatal drowning incidents requiring hospitalisation among females in New Zealand. Of these, 261 were fatal (24.0%) and 826 (76.0%) were hospitalisations. Fatal drowning rates ranged from a high of 1.05 per 100 000 people in 2008 to a low of 0.35 in 2012, whereas hospitalisations ranged from a high of 3.28 in 2016 to a low of 1.29 in 2007. Linear trends indicate drowning-related hospitalisations have increased over the study period (y=0.0766 x+1.4271; R2=0.4438), while fatal drownings have decreased (y=−0.0101 x+0.7671; R2=0.1011) (figure 1).

Figure 1

Fatal drowning and hospitalisations rates per 100 000 population and linear trend, females, New Zealand, 2003–2019.

Fatal drowning among females aged 25–64 years is the only age group that reported an increasing trend across the study period (y=0.0053 x+0.5585; R2=0.0114). Drowning-related hospitalisations increased for all age groups, with the largest increase occurring among females aged 65 years and over (y=0.1244 x+0.0965; R2=0.3809) (figure 2).

Figure 2

Fatal drowning and hospitalisations rates per 100 000 population by age group, linear trend, females, New Zealand, 2003–2019.

Children aged 0–4 years recorded the highest rate of fatal drowning (1.60/100 000 population) and drowning-related hospitalisations (8.22). The second highest fatal drowning was seen among females in the 65+ years age group (0.85), while the second highest rate of drowning-related hospitalisations was found in the 15–24 years age group (2.69). When compared with people 65+ years, children 0–4 years also recorded the highest RR of fatal drowning (RR=1.88; 95% CI 1.24 to 2.86) and drowning-related hospitalisation (RR=6.28; 95% CI 4.82 to 8.20) (table 1).

Table 1

Fatal drowning and hospitalisation rates per 100 000 population by age group and ethnicity, RR, 95% CI, females, New Zealand, 2003–2019

People of ‘Other’ ethnicity had the highest RR of drowning, dying at a rate nine times (RR=9.01; 95% CI 0.83 to 98.32) that of people of Asian ethnicity. People of ‘Other’ ethnicity also reported the highest RR of drowning-related to hospitalisations, a rate 25 times that of people of Asian ethnicity (RR=25.08; 95% CI 5.76 to 109.21). Pacific Peoples reported the second highest RR of fatal drowning (RR=2.42; 95% CI 0.30 to 19.76), while Māori females experienced a rate of drowning-related hospitalisation four times as high as Asian people (RR=3.60; 95% CI 0.92 to 14.07) (table 1).

Children aged 0–4 years accounted for 15.3% of drowning fatalities and 24.9% of drowning-related hospitalisations. Drowning among children 0–4 (χ2=10.5; p=0.001) and 5–14 years old (χ2=17.4; p<0.001) were significantly more likely to result in hospitalisation, whereas drowning among those aged 65 years and older was significantly more likely to be fatal (χ2=17.7; p<0.001). New Zealand European was the ethnicity that accounted for the largest proportion of both drowning deaths (52.6%) and hospitalisations (50.8%), followed by Māori (16.9% of deaths; 23.1% of hospitalisations); however, there were no significant differences found between proportion of fatalities and hospitalisations by ethnicity. Similarly, while summer was the season with the largest proportion (49.3%) of drowning deaths and hospitalisations, there was no significant difference detected (table 2).

Table 2

Fatal drowning and drowning-related hospitalisations by age group and ethnicity, χ2 analysis (p value), females, New Zealand, 2003–2019

Due to data collection systems, additional data are available for fatal drowning. Analysis of these variables indicated rivers to be the leading location for fatal female drowning overall (25.7%), accounting for a quarter of all drowning deaths in each age group (0–24 years, 25–64 years and 65+ years). Drowning at beaches was more likely to occur among women aged 25–64 and 65+ years (χ2=12.3; p=0.006). There were no other significant trends by drowning location and age group. Immersion activities accounted for the largest proportion of fatal drowning incident among females of each age group examined. There were no statistically significant differences by age group and activity prior to drowning. Alcohol was known to be involved in 13.0% of all cases and was significantly more likely to be involved among fatal drowning cases of women aged 25–64 years (χ2=8.7; p=0.013). There were no significant differences detected by age and presence of drugs or drugs and alcohol combined. Unsurprisingly, there was a significantly higher proportion of females in the 0–24 years age group to report no drug or alcohol involvement than any other age group (χ2=16.4; p<0.001). Hazardous conditions were significantly more likely to be involved in fatal drowning cases among women aged 25–64 years (χ2=12.9; p=0.002). (table 3).

Table 3

Circumstantial variables related to fatal drowning, X2 (p value), females, New Zealand, 2003–2019

Analysis of ratios of hospital admission and ACC claims to fatal drowning indicates 3.46 hospital admissions and 675.55 ACC claims for every one drowning death. By age group, the highest hospitalisation ratios were seen among 0–4 year old females with 9.00 hospitalisations for each fatality, whereas the highest ACC claims were reported in the 5–14 years age group (1 fatality to 2485.00 ACC claims). The ratio reduces as females age; however, the hospitalisation rate spikes again among females aged 65+ years, with 3.83 hospitalisations per death. Females in this age group record the second lowest number of ACC claims per death at 300.67, with 0–4 year old females recording the lowest number 116.75 per fatality (table 4).

Table 4

Ratio of drowning deaths to drowning-related hospitalisations and drowning-related Accident Compensation Corporation (ACC) insurance claims, females, New Zealand, 2015–2017


Drowning has been identified as a global threat to public health, with research to date focused on patterns of male drowning16–18 to the exclusion of a dedicated focus on females,19 thus perpetuating the gender data gap. This study aimed to examine fatal and non-fatal drowning events (both hospitalisations and accident compensation claims) to gain a clearer picture of what factors are impacting on female drowning to inform future research and prevention interventions.

In New Zealand, as in other nations,26 27 from ages 0–12 years, drowning prevention initiatives focus on both sexes, such as the bathmat campaign for infants28 and the delivery of the national standard for aquatic education ‘Water Skills for Life’ aimed at school age children.29 However, after the preteen years, the focus shifts solely to males. Campaigns targeting males, such as Surf Life Saving New Zealand’s #SaveTheMales30 and the Swim Reaper,31 are much needed and have been successful in reducing the high drowning rate of young males in New Zealand.32 In fact, prevention interventions have contributed to the crude fatal drowning rate in New Zealand declining by 25% in the 10 years between 2005 and 2014.23 However, a lack of focus on females may be a contributing factor to the slow reduction in fatal drowning among females (y=−0.0101 x+0.7671; R2=0.1011) and the rising rates of drowning-related hospitalisations (y=0.0766 x+1.4271; R2=0.4438) in particular, among adult females observed in this study.

As studies in other countries have identified, it is vitally important to draw attention to the full burden of drowning.33–35 This study has identified a significant drowning burden among females with four hospitalisations and a further 676 ACC claims for each fatality. Solely focusing on preventing drowning among males is not going to reduce the overall drowning-related burden on the health system and the broader community. For there to be any change in the rates of female preventable drowning fatalities, hospitalisations and injuries, there must be investment in drowning prevention initiatives targeting females as well. Such initiatives must ensure that females are aware of how to reduce their own drowning risk as adults and not only targeting females in drowning prevention initiatives for young children in their care.

Rivers were identified as the leading location for female fatal drowning, accounting for 26% of all deaths. Beaches, as the second leading location for female drowning (20%), have a dedicated organisation (Surf Life Saving New Zealand) focused on reducing drowning at such environments. Rivers, however, lack this dedicated focus, and prevention of drowning at these locations would benefit from further work, including exploring if sex-based differences in river visitation and usage as identified in Australian research,36 also apply in the New Zealand context.

This study has identified that 30% of drowning fatalities occurred when conditions were hazardous. This indicates that many females are underestimating the conditions and engaging in risky behaviours, leading to fatal drowning. Traditionally, initiatives regarding risk-taking behaviour around water has been aimed at males, particularly adolescent and younger adult males.17 However, studies indicate that gender differences in risk-taking are narrowing over time,37 providing justification for the need to ensure females are also aware of risk factors for drowning and safe behaviours to reduce this risk in the future.

Alongside exposure to hazardous conditions, combining alcohol and aquatic activity is another risk factor for drowning.38 While studies have typically explored alcohol-related risk-taking behaviour from the perspective of young males,39 data from Australia indicates similarly high levels of alcohol consumption among females and males at river locations.40 This study identified 13% of all fatal drowning cases among females in New Zealand were known to involve alcohol. More broadly, there is evidence of gender convergence in alcohol consumption in New Zealand,41 indicating a need to ensure alcohol-related drowning prevention education and campaigns are also targeted at females.

There are several strengths of this study. This research is the first to solely explore female drowning, an area so far vastly underexplored, despite accounting for a significant proportion of the overall drowning burden. This study also is the first to examine fatal and non-fatal drowning, the latter through the use of hospitalisation and accident compensation claims to further quantify the full burden of drowning. The use of coronial data allows for detailed causal information to be examined. The longitudinal nature of theses data allows for the exploration of trends over time. There are, however, several limitations. Limited variables available for hospitalisation data means comparison with fatal drowning can only be explored on the basis of age, ethnicity and season. The ACC data are also limited, being available for the calendar years 2015–2017 only. As such, ratios of fatal drowning to hospitalisations and ACC claims can only be calculated for this 3-year period. Future studies should explore the feasibility of accessing hospital and ACC data by location and activity to further inform prevention efforts. There are a variety of fields for ACC claimants to complete, some mandatory, some not, resulting in variability in the nature and quality of the descriptions claimants provide. While the data included are largely representative of the claims received by ACC, the data WSNZ provided should not be considered a completely definitive measure of the claims ACC received in the relevant period (ie, there could be more claims than recorded). This is, however, the first time accident compensation data have been compared with deaths and hospitalisation data to provide a full picture of drowning, and as such, this study addresses an important gap in the literature.


For decades, the focus of drowning prevention research and interventions among adolescents and adults has been on males. However, this study has identified the burden of fatal and non-fatal unintentional drowning among females in New Zealand, highlighting drowning as not only being a male issue. There are opportunities to broaden interventions traditionally targeting males on topics such as alcohol involvement and risk-taking behaviours to include females. Such interventions will be successfully applied to females after further research on women’s attitudes and behaviours around water have been undertaken. It is hoped that by drawing attention to the gender data gap in drowning, prevention efforts can be broadened before the overall drowning toll (fatal and non-fatal drowning) among female adolescents and adults in Aotearoa, New Zealand, increases any further.

What is already known on the subject

  • Drowning is a global public health threat that disproportionately impacts males.

  • Despite females accounting for a third of the global burden, there have been no dedicated studies exploring female drowning.

  • This lack of dedicated research perpetuates the gender data gap.

What this study adds

  • The first dedicated study to explore female fatal and non-fatal drowning.

  • An identification of temporal trends and risk factors for female drowning in New Zealand.

  • Ratios of non-fatal drowning hospitalisations and Accident Compensation Commission scheme drowning claims to fatal drowning.

Data availability statement

Data may be requested and a data access agreement entered into if deemed to be a suitable project. Please contact

Ethics statements

Patient consent for publication

Ethics approval

Water Safety New Zealand (WSNZ) has agreements with Coronial Services New Zealand, the National Coronial Information System (Australia) (NZ008) and the New Zealand Ministry of Health (2007–0825) to access data in order to maintain DrownBase. The protocols of DrownBase access adhere to the principles of the New Zealand Privacy Act 2020. A data access agreement is in place between WSNZ and the Accident Compensation Corporation (ACC) to access anonymised ACC data as requested for research.


This study is supported by Water Safety New Zealand. The drowning prevention work of Water Safety New Zealand is supported by the New Zealand Government.



  • Twitter @amyepeden

  • Contributors KR conceptualised the study and was in charge of data curation. AEP conducted analysis and data visualisation. KR and AEP drafted the manuscript. Both authors approve the submitted version.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer reviewed.