Male Sexual Function in New Zealand: A Population-Based Cross-Sectional Survey of the Prevalence of Erectile Dysfunction in Men Aged 40-70 Years

J Sex Med. 2017 Jul;14(7):928-936. doi: 10.1016/j.jsxm.2017.05.011.


Background: Sexual function declines with age and erectile dysfunction (ED) is a common condition worldwide; however, prevalence rates vary markedly between populations and reliable data specific to New Zealand (NZ) are lacking.

Aim: To assess the prevalence of ED in NZ men using a population-based cross-sectional survey.

Methods: Postal questionnaires were sent, according to a modified Dillman method, to a randomly selected age-stratified population-based sample of 2,000 men 40 to 70 years old obtained from the electoral roll. Self-reported erectile function was assessed using the five-item International Index of Erectile Function (IIEF-5) and the single-question self-assessment tool.

Outcomes: The prevalence of ED is presented as crude, age-adjusted to the distribution of the NZ population, and standardized to the World Health Organization World Standard Population (WSP). Associations between sexual function and age were analyzed using χ2 test.

Results: The response rate was 30% (599) and 28% (562) were complete for analysis. The crude prevalence of ED was 42% (22% mild, 10% mild to moderate, 6% moderate, and 4% severe), the age-adjusted prevalence was 38%, and the WSP-adjusted prevalence was 37%. Among men reporting ED, 16% were medically diagnosed and 22% were treated. ED affected 24% of men in their 40s, 38% in their 50s, and 60% in their 60s (P < .001). Age was associated with a significant increase in diagnosed ED (P = .001), treated ED (P = .006), dissatisfaction with current sexual function (P < .001), associated anxiety or depression (P = .023), and a decrease in sexual activity (P < .001).

Clinical translation: Approximately one in three NZ men 40 to 70 years old might have ED. Although comparable to overseas populations, this prevalence is high.

Strengths and limitations: This study provides the most reliable, comprehensive, and current information on ED and its risk factors in NZ men. Strengths include the large sample, the use of random selection from a population-based sampling frame, established effective survey methods, and the validated IIEF-5. Limitations include the inability of cross-sectional data to determine causation, non-sampling errors associated with the population-based sampling frame, the low response rate, the inability to assess non-respondents, the possibility of men with ED who were sexually inactive not responding or not completing the IIEF-5, and the inherent inability to rule out recall bias.

Conclusion: ED is a marker of subclinical cardiovascular disease. The high prevalence and low levels of diagnosis and treatment indicate a lost opportunity for timely intervention to delay or prevent the progression toward clinical disease. Quilter M, Hodges L, von Hurst P, et al. Male Sexual Function in New Zealand: A Population-Based Cross-Sectional Survey of the Prevalence of Erectile Dysfunction in Men Aged 40-70 Years. J Sex Med 2017;14:928-936.

Keywords: Erectile Dysfunction; Five-Item International Index of Erectile Function; New Zealand; Population-Based Study; Prevalence; Wellness, Lifestyle and Diet (Well-LaD) Study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cross-Sectional Studies
  • Depressive Disorder / epidemiology
  • Depressive Disorder / etiology
  • Erectile Dysfunction / complications
  • Erectile Dysfunction / epidemiology*
  • Erectile Dysfunction / psychology
  • Humans
  • Male
  • Middle Aged
  • New Zealand / epidemiology
  • Population Surveillance
  • Prevalence
  • Random Allocation
  • Risk Factors
  • Self-Assessment
  • Sexual Behavior
  • Surveys and Questionnaires