In the modern days, the developed countries faced the challenges of the high rate of adolescent pregnancy rate. The highest rates were recorded for the USA; thus, the efficacy and safety of contraception amongst adolescent girls became an important and pertinent problem. The article written by Cromer A. et al. (2004) is devoted to this issue of modern adolescent medicine. It’s aimed to compare the bone mineral density in the adolescent girls receiving depot medroxyprogesterone acetate (DPMA) and oral contraceptives (OC) containing both estradiol and levonorgestrel versus those receiving no hormonal treatment.
This prospective cohort study has a 2b level of evidence (CEBM, 2001). This level of evidence for therapy, etiology, prevention, or harm is characterized with the following parameters: “Individual cohort study (including low-quality RCT; e.g., <80% follow-up)”. However, other classifications of evidence also could be used. By the GRADE system, which is in use by Cochrane collaboration currently (Greenhalgh T., 2006), the level of evidence is M (moderate quality). It corresponds to grade B by SORT system (ibid.). But it seems that it is the highest possible level for such studies because it was conducted on the sample of girls who self-selected type of hormonal contraception, and it is impossible to apply randomization for assessing clinical effects of these contraceptives. Also, randomized clinical trials (RCT) are used with the limitations in the studies related to the harm investigation (Greenhalgh T., 2006).
The title of the article clearly reflects the content of the article. She short abstract does not mislead to the content of the study and includes the purpose of the research, describes study design and methodology clearly. All findings of the study are presented in the abstract, and they are corresponding to the main text.
Twenty-nine references are cited in the background section of the article. All these articles were published recently – the oldest source (Katzman DK et al. in the Journal of Clinical Endocrinology and Metabolism) was issued in 1991. All cited facts were taken from the primary source and related to the research problem. The literature analysis contains a critical appraisal of cited references. Thus the authors focused the attention of the reader on such disadvantages of the cited literature like the small size of samples, absence of evidence of low dose estriol pills on the bone density. The significance and pertinence of the problem of osteopenia amongst adolescent girls were clearly shown, and the rationale for the study was provided.
The target auditorium for this study is presented by gynecologists, nurses, and other health care specialists. The findings of the research could be helpful for developing clinical guidelines in the field of adolescent contraception. The negative impact of DMPA on bone health and the potential adverse effect of an OC containing 20 mcg Ethinyl estradiol and 100 mcg levonorgestrel is evident for designing the optimal formulations of contraception.
The study conducted by Cromer A. et al. is the next logical step in investigating the problem of the bone health of adolescent girls. The article is written in classic scientific style, and its content is clearly understandable. The theoretical framework is described in sufficient detail. Both scientific hypotheses and the section of materials and methods include the theoretical statements. The authors focused their attention on the following main theoretical topics: bone remodeling and its dependence on the hormonal stimuli, the selection of the objects for bone mineralization assessment, the explanation of the “recovery” phenomenon after discontinuation of hormonal contraception.
The study purpose was “to conduct a longitudinal comparison on bone mineral density in 370 adolescent girls aged 12-18 who self-selected depot medroxyprogesterone acetate or an oral contraceptive containing 20 mcg Ethinyl estradiol/100 mcg levonorgestrel with that in girls who received no hormonal treatment (control group)” (p. 434). The study was designed as the longitudinal cohort one where three referent groups are formed: girls who received DMPA (n=29), girls who used combined OC (n=79), and a control group (n=109) without any history of hormonal contraception. All procedures, including exclusion and inclusion criteria, methods of bone quality assessment, and statistical tools, are described properly.
The research questions and hypotheses are worded clearly and precisely and flow logically from the purpose of the study. However, there is no explanation why the group of the comparison has significant differences in age, body weight, and gynecological status. The procedure of the statistical analysis is described evidently. The variables were independent, but for the non-independence of repeated measures on the same individuals, the ANCOVA was applied, and post hoc pair-wise comparisons were made using Tukey’s adjustment for multiple comparisons. The null hypothesis was applied if the p-value was less than 0.05.
The findings of the study were highly evident. Both textual and table data contain explicit descriptions and statistical evidence. The interpretation of statistical analysis was made correctly. All results were discussed in a close relationship with the previously stated purpose, questions, and hypotheses. The main focus was made on the statistically significant findings, but all results were also appraised critically from the clinical viewpoint. The discussions section is tightly cross-linked with the theoretical framework and with the reviewed literature. Both strengths and weaknesses of the study were stated. The most important limitations were acknowledged as following: high degree of attrition, significant difference in bone mineral density, chronological and gynecologic age, as well as the interim character of data analysis.
However, the authors insist that all these limitations are mitigated due to the absence of the significant differences in background variables between subjects who were withdrawn from the study those who completed their 12-month observation because all BMD results were adjusted by age, body weight, and racial background and because the subjects which were not under catamnestic supervision in the total sample have no differences with those who completed their 12-month follow-up observation. There is no evidence if the clinical significance of this finding is serious or the negative effects of DMPA use could be mitigated with time, and general maintenance of bone density values could be achieved. Also, the article text omitted the important issue of the risk of fractures related to DMPA use. Another important issue that was not discussed properly is the relationship between the use of DMPA and weight gain, especially amongst overweight adolescent girls.
Because the accomplishment of an optimal peak bone mass during adolescence could prevent further development of osteoporosis, the results of Cromer BA et al. (2004) study have almost certainly important. It seems that the findings of this study are also very important for modern medicine when the age of sexual debate and active sexuality shifted to teenagers’ age amongst girls. However, these data demonstrated that the use of hormonal contraceptive pills is not quite safe for their health. Probably sexual education should be more stressed on the use of mechanic contraception as well as on sexual abstinence during the age when the processes of osteogenesis are the most active.
Because the authors did not analyze the impact of DMPA use on the frequency of bone fractures in the catamnestic period, there is expediently to continue follow-up studies on the issue of osteotropic effects of hormonal contraceptives.
References
Cromer BA., Stager M., Bonny A. et al. (2004) Depot medroxyprogesterone acetate, oral contraceptives and bone mineral density in a cohort of adolescent girls. // J Adolesc Health. – Vol. 35(6) – P. 434-441.
Greenhalgh T. (2006) How to Read a Paper: The Basics of Evidence-based Medicine (Evidence-Based Medicine) BMJ Books; 3 edition – 248 p.