A multicentre, prospective and observational study was conducted by 191 dermatologists from all over Spain to obtain a representative sample of the territory. The study was conducted in accordance with the Declaration of Helsinki (Fortaleza, 2013) and the Good Clinical Practices. All the study's materials were reviewed and approved by ethical committee of Hospital General Universitario Gregorio Marañón (Madrid), and all patients were asked to provide written consent before inclusion. The sample comprised consecutive patients over 18 years old who consulted their dermatologist between January and November 2014 and presented AK lesions at time of inclusion.

Demographics and dermatological profile data were collected at baseline: demographics (age, sex, level of education), reason for consultation (aesthetic concern, believe that AK is a disease, doctor's indication, relatives or friends’ advice); dermatological profile (Fitzpatrick phototype,17 previous treatments for AK (yes/no), number, location and clinical classification of AK lesions that require treatment, length of treatment indicated by the dermatologist (1 day, <1 week, > 2 weeks, >4 weeks). It was not contemplated to perform biopsies of the lesions for this study.

To evaluate habits, attitudes, and understanding of exposure to sunlight, four subscales of the “beach questionnaire”15 were used:

• 1.

  Habits of sun exposure on the beach (3 items with Likert format) as a mean of days and number of hours.

• 2.

  Sunburns on the beach (1 item with Likert format): sunburn is defined as the presence of redness and pain after sun exposure.

• 3.

  Sun protection practices on the beach (6 items with Likert format): put in the shade, wear sunglasses, wear a hat or cap, wear Long-sleeved clothing or long pants, avoid sun during the middle of the day and use high sunscreen.

• 4.

  Knowledge about sun exposure (7 items with dichotomous responses).

An additional item was added to evaluate if patients used to expose themselves to the sun at the moment of the baseline visit (dichotomous response), regardless it was during walks, at the beach, parks or in other circumstances.

To evaluate patients’ concern about AK, dermatologists asked patients about the frequency of skin self-examination and medical dermatologic visits and use of tanning lamps. The following pool of questions were also assessed to evaluate patients’ perceptions about AK with dichotomous format of responses: awareness of AK as a disease, need of treatment, need to avoid sun-exposure. Finally, the dermatologist evaluated the patient's acceptance of the therapeutic plan (rated on a generic numeric scale ranging from 0 (none) to 10 (complete)). items.

Quality of Life (QoL) was evaluated with the Spanish version of the Actinic Keratosis Quality of Life Questionnaire (AKQoL).18 The AKQoL, originally proposed by Esmann et al,12 was adapted and validated for our group and allows assessment of the impact of AK on patients’ QoL. It is composed of three domains or subscales: emotions (fear, guilt, shame, worry and irritation/bother), function (personal views of QoL, social life and appearance) and control over life in general. The questionnaire comprises nine items scored on a 4-point scale ranging from 0 (rarely/not at all) to 3 (very much/all the time). The total possible score ranges from 0 to 27 with higher scores indicating greater impairment of QoL.

Follow-up visits were performed between one and three months after baseline in patients receiving therapy for AK in order to obtain data about adherence to treatment and clinical outcomes.

Adherence to treatment was evaluated by means of the dermatologist's estimate of the proportion of days with correct application of treatment (100% of days: complete adherence; ≥80%: correct adherence and <80%: non-adherence) and by Morisky-Green test - MGT,19 a self-reported measure of medication taking with four items that patients were asked to complete at home before the follow up visit.

Clinical outcomes (complete remission and treatment discontinuation) were also collected and recorded by dermatologists at the follow up visit.

Continuous variables were summarized and are presented as the number of valid cases (n), as means (standard deviation) (SD), medians and percentiles, and extreme values (minimum and maximum), while categorical variables are described by the number of valid cases and percentage of each category. Comparisons between groups were performed using Pearson's Chi-square tests for categorical variables and one-way ANOVA tests for numerical variables. Inferential analysis was performed for variables such as length of treatment (<1 week or ≥2 weeks), adherence (according to the MGT) and impairment on QoL (mean score of AKQoL). The associations between the “beliefs and attitudes of patients” and “length of treatment” with “adherence to treatment” and the association between “clinical outcome” and “length of treatment” were presented as Odds Ratio (OR) with Confidence Intervals at 95% [95%CI]. Patients with a single-day treatment were excluded when analysing these associations.

A total of 1240 patients (mean age 73.6 (10.55) years, range 31 - 98 years) were included in the study and 1159 (93.5%) of them completed it. Main reasons for consultation to dermatologist were “physician referral” (59.2%) and “think that AK is a disease” (35.2%).

AK lesions were most frequently located on the face and scalp with an average duration of 13.4 (6 months). Treatment for AK was prescribed attending to the differences between the AK lesions presented in patients. One to five clinically visible AK lesions were found in the intended-to-treat area in 50.8% of cases, 35.9% presented six to twelve clinically visible AK and 11.6% presented more than 12 lesions. There were 76% of patients with AK history prior to inclusion in the study. The 66% of patients received treatment following a previous indication; almost 37% of patients had been previously treated regarding older lesions, and a 23.2% received treatment at their own request.

For more details about patients’ characteristics and dermatological profile see Table 1.

At baseline, 53.4% patients reported daily sun-exposure, mostly during daily walks. Approximately 40% had sunbathed at the beach, parks or other places eventually for more than 30 days in the last year. Use of tanning lamps was reported only in 19 cases. Photoprotective measures during sun exposure are described in Table 2.

Regarding concerns about AK, self-examination of the lesions was reported in 59.5% of cases, normally once a month (31.5%) or even daily (21.7%), and most of the patients had the conviction that treatment was necessary to improve/heal such lesions (70% very/totally convinced). Globally, the majority of patients answered the correct response in all seven items of the questionnaire of knowledge about sun-exposure. In five of those items success rate in this questionnaire was around 66% to 93% but in two items regarding the safety of sunbathing with sunscreen or being tanned patients scored below 60% of success. Mean global score on the generic questionnaire about sun-exposure knowledge was 5.38 (1.45) out of seven (Table 3).

Both dermatologist and patients agreed on the therapeutic plan in 78% of cases. Patients’ mean acceptance was rated as 8.42 (1.35) out of ten. Ninety patients received treatments of a single day duration. In the rest of cases in which therapy was prescribed, 73.8% patients received a therapy that required an application for a week or less.

Patients defined as compliant according to the MGT's criteria presented specific differences regarding beliefs and attitudes towards AK and skin care, since they were more likely to consider AK as a disease and to believe that it needs to be treated, and also more aware that they needed to avoid direct sun-exposure (Table 4). These patients also showed higher scores on acceptance of the therapeutic plan when compared with non-compliers (9.70 (1.23) vs 9.11 (1.40); p<0.001). No significant differences were observed between “adherent” and “non-adherent” patients regarding other concerns like “suffering a disease that requires chronic treatment” or their “aesthetic concerns”.

At the end of the study, only 57 patients had not completed treatment as intended, while 55.6% of whole study population achieved complete remission. Global MGT score was 3.55 (0.87) and maximum level of adherence (4 points) was reached by 72.5% of cases (Table 5).

Mean overall AKQoL score at baseline was 6.23 (4.63) and, regarding subscales results, PIQA's population scored a mean of 2.23 (1.95) (out of 9) in “Function” domain, 2.22 (1.95) (out of 9) in “Emotion” domain and 1.29 (1.30) (out of 6) in “Control over life in general” domain. Inferential analysis suggested that patients with higher levels of concern were more likely to show more impaired QoL (Figure 1). Comparison by sex reveals that AK had a greater effect on women's QoL (p <0.001). A higher negative impact on patients’ QoL was observed in cases who perform self-examination of AK lesions (p<0.001), consider AK as a disease (p<0.001) and/or believe that moisturizers can prevent skin aging (p=0.002). Receiving previous treatment for AK was another factor that had a significant impact on QoL (p<0.05) (fig. 1). AK severity assessed by number of lesions did not significantly influence QoL (p=0.194).

Figure 1.

Factors influencing on QoL.

*p<0.05; **p<0.001.

One-way ANOVA test.

(0.18MB).

To study the impact of treatment's duration we excluded ninety patients that had received a single-day therapy (basically cryotherapy and surgery). Thus, in 93.1 of cases, patients received a specific treatment for more than one day of duration and 79.3% of them applied the medication on 100% of days determined by dermatologist, while 94% showed correct adherence (application of medication on ≥80% of the intended days).

According MGT's assessment, 767 patients (72.4%) met the criteria to be considered adherent to the treatment. Comparison between patients’ length of treatment regarding MGT scores showed that patients with therapies longer than a week were six times less likely to show adherence to treatment. Significant differences in three out of four items of MGT were observed, all of them related with the lack of application of a dose (Table 5).

Statistical significant differences were found between those patients receiving treatment that required use/application for less than a week and those with longer treatments in clearance rates and proportion of cases with complete or correct adherence regarding compliance rate with the treatment's application. Furthermore, complete remission was significantly more frequent in patients receiving treatments of <1 week and patients scheduled to receive treatment lasting longer than a week were four times more likely to discontinue (Table 6). There was complete remission in 55.6% of patients against 41.6% of patients which presented partial remission. It also must be noted that there were a very little number of patients (n=4) which discontinued the treatment by self-decision.